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Title: Science in Short Chapters
Author: Williams, W. Mattieu
Language: English
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SCIENCE
IN
SHORT CHAPTERS.
BY
W. MATTIEU WILLIAMS, F.R.A.S., F.C.S.
AUTHOR OF
“_The Fuel of the Sun_,” “_Through Norway with a Knapsack_,”
“_A Simple Treatise on Heat_,” _etc._
NEW YORK:
JOHN B. ALDEN, PUBLISHER.
1883.
PREFACE.
I am not aware that this reprint of some of my scattered notes and
essays demands any apology.
The practice of making such collections and selections by the author
himself has now become very general, and is much better done thus than
by friends after his death.
Besides this, it supplies a growing want of these busy times, when so
many of us are prevented by the struggles of business from sitting down
to the consecutive systematic study of a formal treatise.
I have kept this demand steadily in view throughout, by selecting
subjects which are likely to be interesting to all readers who are
sufficiently intelligent to prefer sober fact to sensational fiction,
but who, at the same time, do not profess to be scientific specialists.
In the writing of these papers my highest literary ambition has
always been to combine clearness and simplicity with some attempt at
philosophy.
W. M. W.
WILLESDEN, _September, 1882_.
CONTENTS.
PAGE
The Fuel of the Sun 7
Dr. Siemens’ Theory of the Sun 38
Another World Down Here 41
The Origin of Lunar Volcanoes 50
Note on the Direct Effect of Sun-Spots on Terrestrial Climates 56
The Philosophy of the Radiometer and its Cosmical Revelations 59
On the Social Benefits of Paraffin 65
The Solidity of the Earth 72
A Contribution to the History of Electric Lighting 75
The Formation of Coal 88
The Solar Eclipse of 1871 93
Meteoric Astronomy 104
The “Great Ice Age” and the Origin of the “Till” 112
The Barometer and the Weather 140
The Chemistry of Bog Reclamation 159
Aerial Exploration of the Arctic Regions 170
The Limits of our Coal Supply 189
“The Englishman’s Fireside” 213
“Baily’s Beads” 221
The Coloring of Green Tea 223
“Iron Filings” in Tea 227
Concert-Room Acoustics 231
Science and Spiritualism 237
Mathematical Fictions 251
World-Smashing 257
The Dying Trees in Kensington Gardens 261
The Oleaginous Products of Thames Mud: Where they Come from
and Where they Go 266
Luminous Paint 269
The Origin and Probable Duration of Petroleum 273
The Origin of Soap 281
Oiling the Waves 285
On the so-called “Crater Necks” and “Volcanic Bombs” of
Ireland 290
Travertine 296
The Action of Frost in Water-Pipes and on Building Materials 300
The Corrosion of Building Stones 308
Fire-Clay and Anthracite 312
Count Rumford’s Cooking-Stoves 320
The “Consumption of Smoke” 327
The Air of Stove-Heated Rooms 332
Ventilation by Open Fireplaces 337
Domestic Ventilation 341
Home Gardens for Smoky Towns 351
Solids, Liquids, and Gases 367
Murchison and Babbage 386
Atmosphere _versus_ Ether 389
A Neglected Disinfectant 392
Another Disinfectant 393
Ensilage 394
The Fracture of Comets 396
The Origin of Comets 398
SCIENCE IN SHORT CHAPTERS.
THE FUEL OF THE SUN.
I offer the following sketch of the main argument which is worked out
more fully in the essay I published in January, 1870, under the above
title, hoping that many who hesitate to plunge into a presumptuous
speculative work of more than 200 octavo pages may read this article,
and reflect upon the subject.
The book has been handled in a most courteous and indulgent spirit
by all the reviewers who have noticed it, but none have ventured
to grapple with the argument it contains, although every possible
opportunity and provocation for doing so is designedly afforded. It all
rests upon the question which is discussed in the first three chapters,
viz., whether the atmosphere which surrounds our earth is limited or
unlimited in extent? If my reasoning upon this fundamental question
is refuted, all that follows necessarily falls to the ground. If I am
right, all our standard treatises on pneumatics and meteorology, which
repeat the arguments contained in Dr. Wollaston’s celebrated paper,
must be remodeled. At the outset, I reprint that paper, and point out a
very curious and monstrous fallacy which, for half a century, remained
undetected, and had been continually repeated.
As the main point of issue between myself and Dr. Wollaston is merely
a question of very simple arithmetic and geometry, nothing can be
easier than to set me right if I am wrong; and, as the philosophical
consequences depending upon this issue are of vast and fundamental
importance, the question cannot be ignored by those who stand before
the world as scientific authorities, without a practical abdication
of their philosophical responsibilities. Any man who publishes an
astronomical or meteorological treatise without discussing this
question, which stands before him at the threshold of his subject,
is unfit for the task he has undertaken, and unworthy of public
confidence. This may appear a strong conclusion just now, but a
few years will be sufficient to graft it firmly into the growth of
scientific public opinion.[1]
“The Fuel of the Sun” is simply an attempt to trace some of the
consequences which must of necessity result from the existence of an
universal atmosphere, and it differs from other attempts to explain
the great solar mystery, by making no demands whatever upon the
imagination, _inventing_ nothing,—no outside meteors, no new forces
or materials. It supposes nothing whatever to exist but the known
facts of the laboratory—the familiar materials of the earth and its
atmosphere. It is shown that these materials and the forces residing
within them must of necessity produce a sun, and manifest eternally all
the observed solar phenomena, provided only they are aggregated in the
quantities which our own central luminary presents, and are surrounded
by attendant planets, such as his. Nothing is assumed or taken for
granted beyond the simple fundamental hypothesis that the laws of
nature are uniform throughout the universe. The argument thus conducted
leads us step by step to a natural and connected explanation of the
following important phenomena:—
1. The sources of solar and stellar heat and light.
2. The means by which the present amount of solar heat and light must
be maintained so long as the solar system continues in existence.
3. The origin of the general and particular phenomena of the sun-spots.
4. The cause of the varying splendor of the photosphere, including such
details as the “faculæ,” “mottling,” “granulations,” etc., etc.
5. The forces which upheave the solar prominences.
6. The origin of the corona and zodiacal light.
7. The origin of the meteorites and the asteroids.
8. The meteorological phenomena of the planets.
9. The origin of the rings of Saturn.
10. The origin of the special structure of the nebulæ.
11. The source of terrestrial magnetism, and its connection with solar
activity.
The first and second chapters are devoted to an examination of the
limits of atmospheric expansibility. The experimental investigations
of Dr. Andrews, Mr. Grove, Mr. Gassiot, and M. Geissler are cited to
prove that the expansibility of the atmosphere is unlimited, and other
cosmical evidence is adduced in support of this conclusion.
As this, which is really the foundation of the whole argument, is
directly opposed to the views expressed by Dr. Wollaston, in his
celebrated paper on “The Finite Extent of the Atmosphere,” published
in 1822, and generally accepted as established science, this paper is
reprinted in the second chapter, and carefully examined.
Dr. Wollaston says “that air has been rarefied so as to sustain 1-100th
of an inch of barometrical pressure,” and further, that “beyond this
limit we are left to conjectures founded on the supposed divisibility
of matter; if this be infinite, so also must be the extent of our
atmosphere.”
I contend that our knowledge of the whole subject is fundamentally
altered since these words were written. We are no longer “left to
conjectures founded on the supposed divisibility of matter” to
determine the possibility of further expansibility than that indicated
by 1-100th of an inch of barometrical pressure, as we now have means
of obtaining ten times, a hundred times, a thousand times, or even
an infinitely greater rarefaction than Wollaston’s supposed limit,
an apparently absolute vacuum being now obtainable; and although the
transmission of electricity affords a means of testing the existence of
atmospheric matter with a degree of delicacy of which Wollaston had no
conception, we are still unable to detect any indication of any limit
to its expansibility.
The most remarkable part of Dr. Wollaston’s paper is the _reductio ad
absurdum_ by which he seeks to finally demonstrate the finite extent of
our atmosphere. He maintains, as I do, that if the elasticity of our
atmosphere is unlimited, its extension must be commensurate with the
universe, that every orb in space will, by gravitation, gather around
itself an atmosphere proportionate to its gravitating power, and that,
by taking the known quantity of the earth’s atmosphere as our unit, we
may calculate the amount of atmosphere possessed by any heavenly body
of which the mass is known. On this basis Dr. Wollaston calculates
the atmosphere of the sun, and concludes that its extent will be so
great as to visibly affect the apparent motions of Mercury and Venus,
when their declination makes its nearest approach to that of the sun.
No such disturbance being actually observable, he concludes that such
an atmosphere as he has calculated cannot exist. In like manner he
calculates the atmosphere of Jupiter, and finds it to be so great, that
its refraction would be sufficient “to render the fourth satellite
visible to us when behind the centre of the planet, and consequently to
make it appear on both (or all) sides at the same time.”
On examining these calculations, I have discovered the very curious
error above referred to. As this is a matter of figures that cannot
be abridged, I must refer the reader to the original calculations. I
will here merely state that Wollaston’s method of calculating the solar
gravitation atmosphere and that of Jupiter and the moon leads to the
monstrous conclusion that, in ascending from the surface of the given
orb, we always have the same limited amount of atmospheric matter above
as that with which we started, although we are continually leaving a
portion of it below.
Wollaston’s mistake is based on the assumption that, under the
circumstances supposed, the atmospheric pressure and density, at any
given distance from the centre of the given orb, will vary inversely
with the square of that distance. As the area of the base upon which
such pressure is exerted varies _directly_ with the square of the
distance, the total atmosphere above every imaginable starting-distance
would thus be ever the same. That this assumption, so utterly at
variance with the known laws of atmospheric distribution, should have
remained unchallenged for half a century, and that the conclusions
based upon it should be accepted by the whole scientific world, and
repeated in standard treatises, such as those of the “Encyclopedia
Britannica,” etc., etc., is, I think, one of the most remarkable
curiosities presented by the history of science. If it were merely
a little cobweb in some obscure corner of philosophy, there would
be nothing surprising in its escape from the besom of scientific
criticism; but this is so far from being the case, that it has hung,
since 1822, like a dark veil obscuring another, a wider, and more
interesting view of the universe which the idea of an universal
atmosphere opens out. But I must now proceed to the next stage of the
argument.
Starting from the conclusion reached in the previous chapters, that
the atmosphere of our earth is but a portion of an universal elastic
medium which it has attached to itself by its gravitation, and that
all the other orbs of space must, in like manner, have obtained
their proportion, I take the earth’s mass, and its known quantity of
atmospheric envelope as units, and calculating by the simple rule I
have laid down in opposition to Wollaston’s, I find that the total
weight of the sun’s atmosphere should be at least 117,681,623 times
that of the earth’s, and the pressure at its base equal, at least, to
15,233 atmospheres. What must be the results of such an atmospheric
accumulation?
The experiment of compressing air in the condensing syringe, and
thereby lighting a piece of German tinder, is familiar to all who have
studied even the rudiments of physical science. Taking the formulæ of
Leslie and Dalton, and applying them to the solar pressure of 15,233
atmospheres, we arrive according to Leslie, at the inconceivable
temperature of 380,832° C., or 685,529° F., as that due to this amount
of compression, or, according to Dalton, at 761,665° F. What will be
the effects of such a degree of heat upon materials similar to those
of which our earth is composed?
Let us first take the case of water, which, for reasons I have stated,
should be regarded as atmospheric, or universally diffused matter.
This brings us to a subject of the highest and widest philosophical
and practical importance. I refer to the antagonism between the force
of heat and that of chemical combination, to which the French chemists
have given the name “dissociation.” Having myself been unable to find
any satisfactory English account of this subject at a time when it had
already been well treated by French and German authors, in the form of
published lectures and cyclopædia articles, I assume that others may
have encountered a similar difficulty, and therefore dwell rather more
fully upon this part of my present summary.
It appears that all chemical compounds may be decomposed by heat, and
that, at a given pressure, there is a definite and special temperature
at which the decomposition of each compound is effected. For the
absolute and final establishment of the universality of this law
further investigations are necessary, actual investigations having
established it as far as they have gone, but these have not been
exhaustive.
There appears to be a remarkable analogy between dissociation and
evaporation. When a liquid is vaporized, a certain amount of heat is
“rendered latent,” and this quantity varies with the liquid and with
the pressure, but is definite and invariable for each liquid at a given
pressure. In like manner, when a compound is dissociated, a certain
amount of heat is “rendered latent,” or converted into dissociating
force, and this varies with each compound and with the pressure, but
is definite and invariable for each compound at a given pressure.
Further, when condensation occurs, an amount of heat is evolved, as
temperature, exactly equal to that which was rendered latent in the
evaporation of the same substance under the same pressure; and, in like
manner, when chemical re-combination of dissociated elements occurs, an
amount of heat is evolved, as temperature, exactly equal to that which
disappeared when the compound was dissociated by heat _alone_ under
the same pressure.
According to the recently adopted figures of M. Deville, the
temperature at which the vapor of water becomes dissociated under
ordinary atmospheric pressure is 2800° C., and the, quantity of heat
which disappears, as temperature, in the course of dissociation is 2153
_calorics_, _i.e._, sufficient to raise 2153 times its own weight of
_liquid_ water 1° C.; but, as the specific heat of aqueous vapor is
to that of liquid water as 0·475 to 1, that latent heat expressed in
the temperature it would have given to aqueous vapor is = 4532° C., or
8158° F.
In order to render the analogy between the ebullition and dissociation
of water more evident and intelligible, I will state it as follows:—
To commence the ebullition of To commence the dissociation of
water under ordinary pressure, aqueous vapor under ordinary
a temperature of 100° C., or pressures, a temperature of
212° F., must be attained. 2800° C., or 5072° F., must be
attained.
To complete the ebullition of a To complete the dissociation of
given quantity of water, an a given quantity of aqueous
amount of heat must be applied, vapor, an amount of heat must
sufficient to have raised be applied sufficient to have
the water 537° C., or 968° F., raised the vapor 4532° C., or
above its boiling-point, had it 8158° F., above its dissociation-
not evaporated. point had it not decomposed.
In order that a given quantity of In order that a given quantity of
vapor of water shall condense, the elements of water may combine,
it must give off sufficient heat they must give off sufficient
to raise its own weight of water heat to raise their own
537° C., or 968° F. weight of aqueous vapor 4532°
C., or 8158° F.
I have expressed these generalizations and analogies rather more
definitely than they have been hitherto stated, but those who are
acquainted with the researches of Deville, Cailletet, Bunsen, etc.,
will perceive that I am justified in doing so.[2]
With the general laws of the dissociation of water thus before us,
we may follow out the necessary action of the above-stated pressure
and consequent evolution of heat in the lower regions of the solar
atmosphere upon the large proportion of aqueous vapor which I have
shown that it should contain.
It is evident that the first result will be separation of this water
into its elements, accompanied with a loss of temperature corresponding
to the latent heat of dissociation. We may assume that in the lower
regions of the solar atmosphere the free heat evolved by mechanical
compression will be more than sufficient to dissociate the whole of the
aqueous vapor, and thus the dissociated gases will be left at a higher
temperature than was necessary to effect their dissociation. Their
condition will thus be analogous to that of superheated steam: they
will have to give off some heat before they can _begin_ to combine.[3]
There will, however, be somewhere an elevation at which the heat
evolved by the joint compression of the elementary and combined gases
will be just sufficient to dissociate the latter, and here will be the
meeting surface of the combined and the uncombined constituents of
water. There will be a sphere containing combined oxygen and hydrogen
surrounded by an atmospheric envelope containing large quantities of
aqueous vapor, and the temperature at this limiting surface will be
equal to that of the oxyhydrogen flame under a corresponding pressure.
What will occur under these conditions? Will the “detonating gases”
behave as in the laboratory? Obviously not, as a glance at the third
of the above parallel propositions will show. The dissociated gases
cannot combine without giving off their 4532° of latent heat as actual
temperature. This can only be effected by communication with matter
which is cooler than itself.
If a bubble of steam is surrounded by water maintained at the boiling
temperature, it will not condense at all, because any effort of
condensation would be accompanied with an evolution of heat exactly
sufficient to evaporate its own result. If, however, the surrounding
water is slowly radiating, or otherwise losing its heat, the enclosed
bubble of steam will condense proportionately, by giving off to its
envelope an amount of its latent heat just sufficient to maintain the
water at the boiling-point.
For further illustration, let us conceive the case of a certain
quantity of the elements of water heated exactly to the temperature
of dissociation, and confined in a vessel the sides of which are
maintained externally at precisely the same temperature as the
gases within, so that no heat can be added or taken away from them.
No sensible amount of combination can take place, as the first
infinitesimal effort of combustion, or combination, would set free
just the amount of heat required to decompose its own result. Let us
now suppose a modification of these conditions, viz., that the vessel
containing the dissociated gases, at the temperature of dissociation,
shall be surrounded with bodies cooler than itself, _i.e._, capable
of receiving more heat from it than they radiate towards it; there
would then take place just so much combustion as would set free the
amount of heat required to maintain the temperature of the vessel at
the dissociation-point; or, in other words, combustion would go on to
the extent of setting free just so much heat as the gaseous mass was
capable of radiating, or otherwise transmitting to surrounding bodies;
and this amount of combustion would continue till all the gases had
combined.
We have only to give this hypothetical vessel a spherical form and an
internal diameter of 853,380 miles—to construct its enveloping sides
of a thick shell of aqueous vapor, etc., and then, by placing in the
midst of the contained dissociated gases a nucleus of some kind, we
are hypothetically supplied with, the main conditions which I suppose
to exist in the sun.
A little reflection upon the application of the above-stated laws to
these conditions will show that the stupendous ocean of explosive gases
would constitute an enormous stock of fuel capable, by its combustion,
of setting free exactly the same quantity of heat as had previously
been converted into decomposing or separating force; the amount of
combustion would always be limited by the possible amount of radiation,
and the radiation would again be limited by the resisting envelope of
aqueous vapor produced by this combustion.
If these conditions existed in a perfectly calm and undisturbed solar
atmosphere, there would be a continually increasing external envelope
of aqueous vapor, and a continually diminishing inner atmosphere of
combustible gases; there would be a gradual diminution of the amount of
solar radiation, and a slow and perpetually retarding progress towards
solar extinction.
It should be noted that, according to this explanation, the _supply_
of heat is originally derived from atmospheric condensation due
to gravitation, that the _storage_ of surplus heat is effected by
dissociation, and its _evolution_ mainly by recombination or combustion.
The great difficulty, that of the perpetual renewal of the solar fuel,
still remains unsolved; the fact that during the millions of years of
geological history we find no indications of any declining average of
solar energy is so far still unexplained by this, as by every other,
attempt to account for the origin of solar and stellar light and heat.
In his inaugural address to the British Association Meeting of 1866,
Mr. Grove put the following very suggestive question:—“Our sun, our
earth, and planets are constantly radiating heat into space; so, in
all probability, are the other suns, the stars, and their attendant
planets. What becomes of the heat thus radiated into space? If the
universe has no limit—and it is difficult to conceive one—there is a
constant evolution of heat and light; and yet more is given off than is
received by each cosmical body, for otherwise night would be as light
and as warm as day. What becomes of the enormous force thus apparently
non-recurrent in the same form?”
This is a grand question, a philosophical thought worthy of the author
of “The Correlation of Physical Forces.” Most philosophical thinkers
will, I believe, agree with me in concluding that a sound reply to it
will solve the great mystery of the everlasting radiations of our sun
and all the other suns of the universe. So long as we regard these
suns as the _sources_ of continually expended forces of light and
heat, their everlasting and unabated renewal becomes a mystery utterly
inscrutable to the human intellect, since the creation of new force, or
any addition to the total forces of the universe, is as inconceivable
to us as any addition to the total matter of the universe. The great
solar question assumes a far more hopeful shape when we admit that all
the forces of past radiations are somewhere diffused in space, and
we ask whether a sun contains any mechanism by which it may collect
and concentrate this diffused force, and thus perpetually gather from
surrounding suns as much as it radiates towards them.
The next part of my work is an attempt to show that such a mechanism
does exist in our solar system, and to explain its action.
We know that if atmospheric air is compressed it becomes heated, that
if this heat is allowed to radiate and the air is again expanded to its
original dimensions, it will be cooled below its original temperature
to an extent precisely equal to the heat which it gave out when
compressed. On this principle I endeavor to explain the everlasting
maintenance of the solar and stellar radiations.
The sun is attended by his train of planets whose orbital motion he
controls, but they in return react upon him as the moon does upon
the earth. If this reaction were regular, like that of the moon
upon the earth, a regular atmospheric tide would result; but the
great irregularity of the dimensions, distances, and velocities of
the planets produces a result equivalent to a number of clashing
irregular tides in the solar atmosphere; or, otherwise stated, the
centre of motion and centre of gravity of the whole system will be
perpetually varying with the varying relative positions of the planets,
and thus the solar nucleus and solar atmosphere will be subject to
irregularities of motion, which, though very small relatively to the
enormous magnitude of the sun, must be sufficient to produce mighty
vortices, and thus effect a continual commingling between the outer and
inner atmospheric strata.
It must be remembered that, according to the preceding, the inner or
lower strata of the solar atmosphere should consist of our ordinary
atmospheric mixture of oxygen and nitrogen, and the dissociated
elements of water and carbonic acid, besides some of the more volatile
elements of the solar nucleus. Outside of this there should be a
boundary limit where the dissociated gases are combining as rapidly
as their latent heat can be evolved by radiation; this will form a
shell or sphere of flame,—the photosphere,—and above or beyond this
will be the sphere of vapors resulting from this combustion, which, by
their resistance to radiation, will limit the evolution of heat and
consequent combustion.
Now the vortices above referred to will break through the shell of
combustion, and drag down more or less of the outer vapor into the
lower and hotter regions of dissociated gases.
As there can be no action without equal and contrary reaction, there
can be no vortices, either in the solar atmosphere or a terrestrial
stream, without corresponding upheavals. These upheavals will eject the
lower dissociated gases more or less completely through the vaporous
jacket which restrains their normal radiations, and, thus liberated,
they will rush into combination with an explosive energy comparable
to that which they display in our laboratories; not, however, with an
instantaneous flash, but with a continuous rocket-like combustion, the
rapidity of which will be determined by the possibility of radiation.
The heat evolved by this combustion, acting simultaneously with the
diminution of pressure, will effect a continually augmenting expansion
of these upheaved gases, and as the rapidity of combustion will be
accelerated in proportion to elevation above the restraining vapors, an
outspreading far in excess of that which would be due to the original
upheaving force, is to be expected.
The reader who is acquainted with the phenomena of the solar
prominences will at once perceive how all these expectations are
fulfilled by actual observations, especially by the more recent
observations of Zöllner, Secchi, etc., which exhibit the typical solar
prominence as a stem or jet rushing upwards through some restraining
medium, and then expanding into a cloud-like or palm-tree form after
escaping from this restraint. I need scarcely add that the clashing
tide waves are the _faculæ_, and the vortices the sun-spots.
My present business, however, is to show how these vortices and
eruptions—this down-rush in one part of the solar atmosphere and
up-rush in another—contribute to the permanent maintenance of the
solar light and heat. It must be understood that these outbursts are
only visible to us as luminous prominences during the period of their
explosive outburst, and while still subject to great expansive tension.
Long after they have ceased to be visible to us their expansion must
continue, until they finally and fully mingle with the medium into
which they are flung, and attain a corresponding degree of rarefaction.
This must occur at tens and hundreds of thousands of miles above
the photosphere, according to the magnitude of the ejection. The
spectroscopic researches of Frankland and Lockyer having shown that
the atmospheric pressure at about the outer surface of the photosphere
does not far exceed that of our atmosphere, I may safely regard all
the upper portion of these solar ejections as having left the solar
atmosphere proper, and become commingled with the general interstellar
medium.
If the sun were stationary, or merely rotating, in the midst of this
universal atmosphere, the same material that is ejected to-day would
in the course of time return, and be whirled into the great sun-spot
eddies; but such is not the case; the sun is driving through the ether
with a velocity of about 450,000 miles per twenty four hours.
What must be the consequence of this motion? The sun will carry its own
special atmospheric matter with it; but it cannot thus carry the whole
of the interstellar medium. There must be a limit, graduated no doubt,
but still a practical limit, at which its own atmosphere will leave
behind, or pass through, the general atmospheric matter. There must be
a heaping or condensation of this matter in the front, a rarefaction or
wake in the rear, and a continuous bow of newly encountered atmosphere
around the boundaries in the opposite direction to that of the sun’s
motion. The result of this must be that a great portion of the ejected
atmospheric matter of the prominences will be swept permanently to
the rear, and its place supplied by the material occupying the space
into which the sun is advancing. We are thus presented with a mighty
machinery of solar respiration; some of this newly arriving atmospheric
matter must be stirred into the vortices, its quantity being exactly
equivalent to that of the old material expired by the explosive
eruptions, and left in the rear.
Now, the new atmospheric matter which is thus encountered and inspired,
is the recipient of the everlasting radiations whose destination is the
subject of Mr. Grove’s inquiry; and these, when thus encountered and
compressed, will of necessity evolve more or less of the heat which,
through millions of millions of centuries they have been gradually
absorbing; while, on the other hand, the expired or ejected matter of
the gaseous eruptions will, like the artificially compressed air above
referred to, have lost all the heat which during its solar existence
it had by compression, dissociation, and re-combination contributed to
the solar radiations. Therefore, when again fully expanded, it will be
cooler than the general medium from which it was originally inspired by
the advancing sun.
The daily supply of fresh atmospheric fuel will be a cylinder of
ether of the same diameter as the sun, and 450,000 miles in length!
I have calculated the weight of this cylinder of ether on the
assumption (which of course is purely arbitrary) that the density of
the interstellar medium is one ten-thousandth part of that of our
atmosphere. It amounts to 14,313,915,000,000,000,000 tons, affording a
supply of 165 millions of millions of tons per second; or, if we assume
the interstellar medium to have a density of only one-millionth of that
of our atmosphere, the supply would be rather more than one and a half
millions of millions of tons per second. The proportion of this which
is effective in the manner above stated is that which becomes stirred
into the lower regions of the sun in exchange for the ejected matter of
the prominences.
I will not here dwell upon the bombardment hypothesis, beyond
observing that my explanation of solar phenomena supplies a continuous
bombardment of the above-stated magnitude without adding anything to
the magnitude of the sun.
So far, then, I answer Mr. Grove’s question, by showing that the
heat radiated into space by each of the solid orbs that people its
profundities, is received by the universal atmospheric medium; is
gathered again by the breathing of wandering suns, who inspire as
they advance the breath of universal heat and light and life; then by
impact, compression, and radiation, they concentrate and re-distribute
its vitalizing power; and after its work is done, expire it in the
broad wake of their retreat, leaving a track of cool exhausted
ether—the ash-pits of the solar furnaces—to reabsorb the general
radiations, and thus maintain the eternal round of life.
But ere this, a great difficulty has probably presented itself to the
mind of the reader. He will refer to the calculations that have been
made in order to determine the actual temperature of the solar surface
and the intensity of its luminosity. Both of these are vastly in excess
of those obtained in our laboratory experiments by the combustion of
the elements of water. Even taking into consideration the dissociated
carbonic acid whose elements should be burning in the photosphere
with those of water, and adding to these the volatile metals of the
solar nucleus whose dissociated vapors must, under the circumstances
stated, be commingled with those of the solar atmosphere, and therefore
contribute to the luminosity by their combustion, still by burning here
on the earth a jet of such mixed gases and vapors we should not obtain
any approach to either the luminosity or the temperature which is
usually attributed to the sun.
I have made a very few simple experiments, the results of which
remove these difficulties. They were conducted with the assistance of
Mr. Jonathan Wilkinson, the official gas examiner to the Sheffield
Corporation, using his photometric and gas-measuring apparatus. We
first determined the amount of light radiated by a single fish-tail
gas-burner consuming a measured quantity of gas per hour. We found when
another was placed behind this, so that all the light of the second
had to pass through the first, that the light of the two (measured by
the illuminating intensity of their radiations upon a screen just as
the solar luminosity has been measured) was just double that of one
flame, three flames (still presenting to the photometric screen only
the surface of one) gave it three times the amount of illumination, and
so on with any number of flames we were able to test. Mr. Wilkinson
has since arranged 100 flames on the same, principle, _i.e._, so that
the 99 hinder flames shall all radiate through the one presented to
the screen, thus affording the same surface as a single flame, but
having 100 times its _thickness_ or _depth_, and he finds that the law
indicated by our first experiments is fully verified; that the 100
flames thus arranged illuminate the screen 100 times as intensely as
the single flame. Other modifications of these experiments, described
in Chapter vii. of “The Fuel of the Sun,” establish the principle that
a common hydrocarbon gas flame is transparent to its own radiations,
or, in other words, that the amount of light radiated from such a
flame, and its apparent intensity of luminosity, is proportionate to
its thickness; therefore the luminosity of the sun may be produced by a
photosphere having no greater intrinsic brilliancy than the flame of a
tallow candle, provided the flame is of sufficient depth or thickness.
I see good reasons for inferring that its intrinsic brilliancy is less
than that of a candle—somewhere between that and a Bunsen’s burner.
A similar series of experiments upon the radiation of the _heat_ of
flames through each other, indicated similar results; but my apparatus
for these experiments was not so delicate and reliable as in the
experiments on light, and, therefore, I cannot so decidedly affirm the
absolute diathermancy of flame to its own radiations. Within the limits
of error of these experiments, I found that with the same radiant
surface presented to the thermometer, every addition to the thickness
of the flame produced a proportionate increase of radiation.
This important law, though hitherto unnoticed by philosophers, is
practically understood and acted upon by workmen who are engaged in
furnace operations. Present space will not permit me to illustrate this
by examples, but in passing I may mention the “mill furnaces,” where
armor-plates and other large masses of iron are raised to a welding
temperature by radiant heat, and the ordinary puddling furnace, where
iron is melted by radiant heat. In both of these special arrangements
are made to obtain a “body” or thickness of radiant flame, while
_intensity_ of combustion is neglected and even carefully avoided.
According to this there are two factors engaged in producing the
radiant effect from a given surface, _intensity_ and _quantity_,
_i.e._, _brilliancy_ and _thickness_ in the case of light, and
_temperature_ and _thickness_ in the case of heat. In the Bude light,
for example, consisting of concentric rings of coal-gas, we have small
intensity with great quantity, in the lime-light we have a mere surface
of great brilliancy but no thickness. If I am right, the surface of
the moon maybe brighter than the luminous surface of the sun, the
peculiarities of moonlight depending upon intensity, those of sunlight
upon quantity of light.
The flame that roars from the mouth of a Bessemer converter has but
small intrinsic brilliancy, far less than that of an ordinary gas
flame, as may be seen by observing the thin waifs that sometimes
project beyond the body of the flame. Nevertheless, its radiations are
so effective that it is a painfully dazzling object even in the midst
of sunny daylight; but then we have here not a hollow flame fed only by
outside oxygen, but a solid body of flame several feet in thickness.
Even the pallid carbonic acid flame which accompanies the pouring of
the spiegeleisen has marvellous illuminating power.
The reader will now be able to understand my explanation of the
sun-spots, of their nucleus, umbra, and penumbra. From what I have
stated respecting the planetary disturbances or the solar rotation,
the photosphere should present all the appearances due to the movements
of a fiery ocean, raging and seething in the maddest conceivable fury
of perpetual tempest. If the surface of a river flowing peacefully
between its banks is perforated with conical eddies whenever it meets
with a projecting rock or obstacle, or other agency which disturbs the
regularity of its course, what must be the magnitude of the eddies
in this ocean of flame and heated gases, when stirred to the lowest
depths of its vast profundity by the irregular reeling of the solar
nucleus within? Obviously, nothing less than the sunspots; those mighty
maelströms into which a world might be dropped like a pea into an
egg-cup.
When the photosphere or shell of combining gases is thus ripped open,
the telescopic observer looks down the vortex, which, if deep enough,
reveals to him the inner regions of dissociated gases and vapors. But
these have the opposite property to that which I have shown to belong
to flame; they are opaque to their own special radiations, while the
flame is transparent to the light of the inner portions of itself.
Thus, the dissociated interior of the solar envelope, though absolutely
white-hot, will be comparatively dark (direct experiment has proved
that the darkness of the spots is only relative).
The sides of the vortex funnel will consist of a mixture of dissociated
gases, flaming gases, and combined gases, and will thus present various
thicknesses of flame, and thereby display the various shades of the
penumbra. Space will not permit me here to follow up the details of
this subject, as I have done in the original work, where it is shown
that if the telescope had not yet been invented, all the telescopic
details of spot phenomena might have been described _à priori_ as
necessary consequences of the constitution I have above ascribed to the
sun.
Not merely the great spot phenomena, but all the minor irregularities
of the photosphere follow with similarly demonstrable necessity. Thus
the many interfering solar tides must throw up great waves, literally
mountainous in their magnitude, the summits and ridges of which, being
raised into higher regions of the absorbing vaporous atmosphere that
envelopes the photosphere, will radiate more freely, its dissociated
matter will combine more abundantly, and will thicken the photosphere
immediately below; this thicker flame will be more luminous than the
normal surface, and thus produce the phenomena of the _faculæ_.
Besides these great ground-swells of the flaming ocean of the
photosphere, there must be lesser billows, and ripples upon these,
and mountain tongues of flame all over the surface. The crests of
these waves, and the summits of these flame-alps, presenting to the
terrestrial observer a greater depth of flaming matter, must be
brighter than the hollows and valleys between; and their splendor must
be further increased by the fact, that such upper ridges and summits
are less deeply immersed in the outer ocean of absorbing vapors,
which limits the radiation of the light as well as the heat of the
photosphere. The effect of looking upon the surface of such a wild
fury of troubled flame, with its confused intermingling of gradations
of luminosity, must be very puzzling and difficult to describe; and
hence the “willow leaves,” “rice grains,” “mottling,” “granules,”
“things,” “flocculi,” “bits of white thread,” “cumuli of cotton wool,”
“excessively minute fragments of porcelain,” “untidy circular masses,”
“ridges,” “waves,” “hill knolls,” etc., etc., to which the luminous
irregularities have been compared.
At the time I wrote, the means of examination of the edge of the sun
by the spectroscope was but newly discovered, and the results then
published referred chiefly to the prominences proper. Since that, a
new term has been introduced to solar technology, the “sierra,” and
the observations of the actual appearances of this sierra precisely
correspond to my theoretical description of the limiting surface of
the photosphere, which was written before I was acquainted with these
observed facts. This will be seen by reference to Chapter x., the
subject of which is, “The Varying Splendor of Different Portions of the
Photosphere.”[4]
But I must not linger any further upon this part of the subject,
but proceed to another, where subsequent discoveries have strongly
confirmed my speculations.
The mean specific gravity of the sun is not quite 1½ times that of
water. The vapors of nickel, cobalt, copper, iron, chromium, manganese,
titanium, zinc, cadmium, aluminium, magnesium, barium, strontium,
calcium, and sodium, have been shown by the spectroscope to be floating
on the outer regions of the sun. None of these could constitute the
body of the sun in a solid or liquid state, and be subjected to the
enormous pressure which such a mass must exert upon itself without
raising the mean specific gravity vastly above this; nor is there any
other kind of matter with which we are acquainted which could exist
within so large a mass in a liquid or solid state, and retain so low a
density.
I must confess that my faith in the logical acumen of mathematicians
has been rudely shaken by the manner in which eminent astronomers have
described the umbra or nucleus of the sun-spots as the solid body of
the sun seen through his luminous atmosphere, and the solid surface of
Jupiter seen through his belts, and have discussed the habitability
of Jupiter, Saturn, Uranus, and Neptune always on the assumption of
their solidity, while the specific-gravity of all of these renders this
surface solidity a demonstrable physical impossibility.
If the sun (or either of these planets) has a solid or liquid nucleus,
it must be a mere kernel in the centre of a huge orb of gaseous matter,
and though I have spoken rather definitely of the solar atmosphere in
order to avoid complication, I must not, therefore, be understood to
suppose that there exists in the sun any such definite boundary to
the base of the atmospheric matter as we find here on the earth. The
temperature, the density, and all we know of the chemistry of the sun
justify the conclusion that in its outer regions, to a considerable
depth below the photosphere, there must be a commingling of the
atmospheric matter with the vapors of the metals whose existence the
spectroscope has revealed. Some of these must be upheaved together with
the dissociated elements of water. They are all combustible, and,
with a few exceptions, the products of their combustion would solidify
after they were projected beyond the photosphere. Much of the iron,
nickel, cobalt, and copper might pass through the fiery ordeal of such
projection, and solidify without oxidation, especially when more or
less enveloped in uncombined hydrogen.
It is obvious that, under these circumstances, there must occur a
series of precipitations analogous to those from the aqueous vapor
of our atmosphere. These gaseous metals, or their oxides, must be
condensed as clouds, rain, snow, and hail, according to their boiling
and metal points, and the conditions of their ejection. We know that
sudden and violent atmospheric disturbance, accompanied with fierce
electrical discharges, especially favor the formation of hailstones
in our terrestrial atmosphere. All such violence must be displayed on
a hugely exaggerated scale in the solar outbursts, and therefore the
hailstone formation should preponderate, especially as the metallic
vapors condense more rapidly than those of water on account of the much
smaller amount of their specific heat, and of the latent heat of their
vapors.
What will become of these volleys of solid matter thus ejected with the
furious and protracted explosions forming the solar prominences? In
order to answer this question, we must remember that the spectroscope,
as recently applied, merely displays the gaseous, chiefly the hydrogen,
ejections; that these great gaseous flames bear a similar relation to
the solid projectiles that the flash of a gun does to the grape-shot
or cannon-ball. Mr. Lockyer says: “In one instance I saw a prominence
27,000 miles high change enormously in the space of ten minutes; and,
lately, I have seen prominences much higher born and die in an hour.”
He has recently measured an actual velocity of 120 miles per second
in the movements of this _gaseous_ matter of the solar eruptions, the
initial velocity of which must have been much greater.[5] If such is
the velocity of the gaseous ejections, what must be that of the solid
projectiles, and where must they go?
A cosmical cannonade is a necessary result of the conditions I have
sketched, and as prominence-ejections are continually in progress,
there must be a continual outpouring from the sun of solid fragments,
which must be flung far beyond the limits of the gaseous prominences.
As the luminosity of these glowing particles must be very small
compared with that of the photosphere, they will be invisible in
the glare of ordinary sunshine; but if our eyes be protected from
this, they may then be rendered visible, both by their own glow and
the solar light they are capable of reflecting. They should be seen
during a total eclipse, and should exhibit radiant streams proceeding
irregularly from different parts of the sun, but most abundantly from
the neighborhood of the spot regions. As these spot regions occupy the
intermediate latitudes between the poles and the equator of the sun,
the greatest extensions of the outstreamings should be N.E. and S.W.,
and S.E. and N.W., while to the N., S., E., and W.—that is, opposite
the poles and equator of the sun—there should be a lesser extension.
The result of this must be an approximation to a quadrilateral figure,
the diagonals of which should extend in a N.E. and S.W., and a S.E. and
N.W. direction, or thereabouts. I say “thereabouts,” because the zone
of greatest activity is not exactly intermediate between the poles and
the equator, but lies nearer to the solar equator.
Examined with the polariscope, these radiant streams should display
a mixture of reflected light and self-luminosity. Examined with the
spectroscope, a faint continuous spectrum due to such luminosity of
solid particles should be exhibited, with possibly a few lines due to
the small amount of vapor which, in their glowing condition, they might
still give off. Besides this, there should appear the spectroscope
indications of violent electrical discharges, which must occur as a
necessary concomitant of the furious ejections of aqueous vapor and
solid particles. All these metallic hailstones must be highly charged,
like the particles of vesicular vapor ejected from the hydro-electric
machine, or the vapors and projectiles of a terrestrial volcanic
eruption.
I need scarcely add that this exactly describes the actually-observed
results of the recent observations on the corona, and that all the
phenomena of this great solar mystery are but necessary and predicable
results of the constitution I ascribe to the sun.
There is a method of manufacturing hypotheses which has become rather
prevalent of late, especially among mathematicians, who take observed
phenomena, and then arbitrarily and purely from the raw material
of their own imagination construct explanatory atoms, media, and
actions, which are shaved and pared, scraped and patched, lengthened
and shortened, thickened and narrowed, till they are made to fit
the phenomena with mathematical accuracy. These laborious creations
are then put forth as philosophical truths, and, _afterwards_, the
accuracy of their fitting to the phenomena is quoted as evidence of
the positive reality of the ethers, atoms, undulations, gyrations,
collisions, or whatever else the mathematician may have thus skilfully
created and fitted. It appears to me that such fitness only proves
the ingenuity of the fitter—the skill of the mathematician—and that
all such hypotheses belong to the poetry of science; they should be
distinctly labelled as products of mathematical imagination, and nowise
be confounded with objective natural truths. Such products of the
imagination of the expert may assist the imagination of the student in
comprehending some phenomena, just as “Jack Frost” and “Billy Wind” may
represent certain natural forces to babies; but if Jack Frost, Billy
Wind, electric and magnetic fluids, ultimate atoms, interatomic ethers,
nervous fluids, etc., are allowed to invade the intellect, and are
accepted as actual physical existences, they become very mischievous
philosophical superstitions.
I make this digression in order to repudiate any participation in
this kind of speculation. Though “The Fuel of the Sun” is avowedly a
very bold attempt to unravel majestic mysteries, I have not sought
_to elucidate the known by means of the unknown_, as do these
inventors of imaginary agents, but have scrupulously followed the
opposite principle. I have invented nothing, but have started from
the experimental facts of the laboratory, the demonstrated laws of
physical action, and have followed up step by step what I understand
to be the necessary consequences of these. Many years ago I convinced
myself that our atmosphere is but a portion of universal atmospheric
matter; that Dr. Wollaston was wrong, and that the compression of this
universal atmospheric matter is possibly the source of solar light
and heat; but as this was long before M. Deville had investigated
the subject of dissociation by heat,[6] I was unable to work out
the problem at all satisfactorily. When I subsequently resumed the
subject, I knew nothing about the corona, and had only read of the “red
prominences” as possible lunar appendages, or solar clouds, or optical
illusions. I had worked out the necessity of the gaseous eruptions,
and their action in effecting an interchange of solar and general
atmospheric matter, as the means of maintaining the solar light and
heat, with no idea of proceeding further with the problem, when the
announcement that the prominences were not merely unquestionable solar
appendages, but were actually upheaved mountains of glowing hydrogen,
suddenly and unexpectedly suggested their identity with my required
atmospheric upheavals. It is true that their observed magnitude far
exceeded my theoretical anticipations, and in this respect I have made
some _à posteriori_ adaptations, especially with the aid of a clearer
understanding of the laws of dissociation which almost simultaneously
became attainable.
In like manner, the necessity of the solid ejections presented
themselves before I knew anything of the recently discovered details of
the coronal phenomena—when I had merely read of a luminous halo which
had been seen around the sun, and relying upon Mr. Lockyer, vaguely
supposed it to be an effect of atmospheric illumination. I inferred
that streams of solid particles must be pouring from the sun, and
showering back again, but had no idea that such streams and showers
were actually visible until I was rather startled on learning that the
corona, instead of being, as I had loosely supposed, a mere uniform
filmy halo, had been described by Mr. De la Rue, in his Bakerian
Lecture on the Eclipse of 1860, as “softening off with very irregular
outline, and sending off some _long streams_,” etc. I was then living
on the sides of a Welsh mountain far away from public libraries, and
being no astronomer, my own books kept me better acquainted with the
current progress of experimental than with astronomical science.
Even when “The Fuel of the Sun” was published I knew nothing of the
American observations of the quadrangular figure of the corona, or
should certainly have then quoted them, nor of the fact revealed by
the Eclipse of December, 1870, that, “wherever on the solar disc a
large group of prominences was seen on Mr. Seabroke’s map, there a
corresponding bulging out of the corona was chronicled on Professor
Watson’s drawing; and at the positions where no prominences presented
themselves, there the bright portions of the corona extended to the
smallest distances from the sun’s limb;” and that Mr. Brothers’s
photographs _all_ show the corona extending much further towards the
west than towards the east, the west being “the region richest in solar
prominences.” I am sorry that the limits of this paper will not permit
me to enter more fully into the bearings of the recent studies of the
corona and the prominences upon my explanations of solar phenomena,
especially as the differences between the inner and outer corona, which
still appear to puzzle astronomers, are exactly what my explanation
demands. I must make this the subject of a separate paper, and proceed
at once to the next step of the general argument.
Assuming that such ejections of solid matter are poured from the
prominences, to what distances may they travel? In attempting to
answer this question, I avowedly ventured upon dangerous ground, for
at the time of writing I only knew that the force of upheaval of the
prominences must be enormous, _probably_ sufficient to eject solid
matter beyond the orbit of the earth and even beyond that of Mars.
Actual measurements of the eruptive velocity of the solar prominences
have since been made, and they are so great as to relieve me of my
quantitative difficulty, and show that I was quite justified in the
bold inference that these eruptions may account for the zodiacal light,
the zones of meteors into which our earth is sometimes plunged, and
even the outer zone of larger bodies, the asteroids.
But how, the reader will ask, can such solids, ejected from the
sun, acquire orbital paths around him? “We have been taught that
the parabola is the necessary path of such ejections.” Mr. Proctor
has evidently reasoned in this manner, for in last April number of
“Fraser’s Magazine” he says that some of my ideas are “opposed to any
known laws, physical or dynamical,” that “there is nothing absolutely
incredible in the conception that masses of gaseous, liquid, or solid
matter should be flung to a height exceeding manifold that of the
loftiest of the colored prominences; whereas it is not only incredible,
but impossible, that such matter should in any case come to circle in a
closed orbit round the sun.”
More careful reading would have shown Mr. Proctor that I have
considered other conditions besides those of the textbooks, that the
case is by no means one of simple radial projection from a fixed body
into free space and undisturbed return. I distinctly stated that “the
recent ejections may have any form of orbit within the boundaries of
the conic sections,” from a straight line returning upon itself, due
to absolutely vertical projection, to a circular orbit produced by
the tangential projection of such curving prominences _as the ram’s
horn_, etc. The outline of the zodiacal light would be formed by the
termination or aphelion portion of these excursions, or of such a
number of them as should be sufficient to produce a visible result.
Again, speaking of the asteroids, in Chapter xiv., I state that “I
should have expected a still greater elongation and eccentricity in
some of them, and such orbits may have existed; but an asteroid with
an orbit of cometary eccentricity that would in the course of each
revolution cross the paths of Mercury, Venus, the Earth, and Mars in
nearly the same plane, and dive through the thickly scattered zodiacal
cluster, both in going to the sun and returning from it, would be
subject to disturbances which would continue until one of two things
occurred. Its tangential force might become so far neutralized and
its orbit so much elongated, that finally its perihelion distance
should not exceed the solar radius, when it would finish its course
by returning to the sun. On the other hand, its tangential velocity
might be increased by heavy pulls from Jupiter, when slowly turning
its aphelion path, and be similarly influenced by friendly jerks in
crossing the orbits of the inferior planets; and thus its orbit might
be widened, until it ceased periodically to cross the path of any of
the planets by establishing itself in an orbit constantly intermediate
between any two. Having once settled into such a path, it would remain
there with comparative stability and permanency. If I am right in this
view of the dynamical history of these older ejections, all the long
elliptical paths of zodiacal particles, meteorites, or asteroids, would
thus in the course of ages become eliminated, and the remaining orbits
would be of planetary rather than cometary proportions.”
A little reflection on the above-stated laws of dissociation will show
that the maximum violence of hydrogen explosion will not occur at the
birth of the ejections, but afterwards, when the dissociated gases
have been already hurled beyond the sphere of restraining vapors. If
my explanation is correct, the typical form of a solar prominence
should be that of a spreading tree with a tall stem. At first the least
resistence to radiation and consequent explosive combination must
be in the vertical direction, as this will afford the shortest line
that can be drawn through the thickness of the surrounding jacket of
resisting vapor; but when raised above this envelope, the dissociated
gases, cooled by their own expansion and comparatively free to radiate
in all directions except downwards, will explode laterally as well as
vertically, and thus spread out into a head. My theoretical prominence
will be, in short, a monster rocket proceeding steadily upwards to a
certain extent, and then gradually bursting and projecting its missiles
in every direction from the vertical to the absolutely horizontal.
Should the latter acquire a velocity of about 300 miles per second,
not merely a closed but even an absolutely circular orbit would be
possible. These and the multitude of weaker lateral ejections, reaching
the sun by short parabolic paths, explain the mystery of the inner
corona.
I need only refer Mr. Proctor to his own recently published book on
the Sun, where he will find on plates 4, 5, and 6 a number of drawings
from Zöllner and Respighi, which so thoroughly confirm my necessary
theoretical deductions that they might be a series of fancy sketches of
my own. When we consider that the base of a prominence is only visible
when it happens to start exactly from the limb of the sun, while the
vastly greater proportion of those which are observed, and have been
drawn, have much of the stem cut off from view by the solar rotundity,
the evidence afforded by such drawings in support of my theoretical
deduction, that the typical form of the solar prominences is that of a
palm-tree or bursting rocket, is greatly strengthened.[7]
In a paper by P. Secchi, dated Rome, March 20, 1871, and published in
the “Comptes Rendus,” March 27, this veteran solar observer speaks of
the prominences as composed of jets, which, “upon reaching a certain
elevation, stop and whirl upon themselves, giving birth to a brilliant
cloud.” This cloud is represented as spreading out on all sides from
the summit of the combined jets. Again he says, “It is very common to
see a little jet spot at a certain elevation above the chromosphere,
and there spread itself out into a _wide hat_ (“_un large chapeau_”) of
an absolutely nebulous constitution.” This outspreading nebulosity is
the flash of the incandescent vapors produced by the explosion which is
theoretically demanded by my explanation to occur exactly in the manner
and place described. These expanded incandescent gases will be rendered
visible by the spectroscopic dilution of the continuous spectrum of
the denser photosphere, while the solid projectiles that must proceed
from them in every direction can only be seen during a solar eclipse.
The observations and drawings of Zöllner and Respighi were, for the
most part, made while my book was in the press, and, like those of
Secchi above quoted, were unknown to me when I wrote; I was then
only able to quote, in support of my theoretical requirements, the
evidences of actually observed tangential ejection afforded by Sir John
Herschel’s account of the great solar storm of September 1, 1859.
Besides this direct tangential projection there are other elements
of motion contributing to the same result, such as the whirl of the
prominences on themselves, their motion of translation on the sun’s
disk, and the rotation of the sun itself.
I must now bring this sketch to a close by stating that, in order
to submit the fundamental question of an universal atmosphere to an
_experimentum crucis_ analogous to that by which Pascal tested the
atmospheric theory of Torricelli, I have calculated the theoretical
density of the atmosphere of the moon and of each of the planets, and
compared the results as severely as I could with the observed facts. As
Jupiter is 27,100 times heavier than the moon, and between these wide
extremes there are six planets presenting great variations of mass,
the probabilities of accidental coincidence are overwhelmingly against
me, and a close concurrence of observed telescopic refraction and
other phenomena with the theoretical atmospheric density must afford
the strongest possible confirmation of the soundness of the basis of
my whole argument. Such a concurrence exists, and some new and very
curious light is unexpectedly thrown upon the meteorology of Mars and
the constitution of the larger planets. The latter, if I am right, must
be miniature suns, _permanently_ red or white-hot, must be something
like a photosphere, surrounded by a sphere of vapor (the outside of
which we see), must have mimic spot vortices and prominences, and in
the case of Saturn must eject volleys of meteoric matter, some of which
should finally settle down into orbital paths, and thus produce the
rings.
These are startling conclusions, and when I reached them they were
utterly at variance with general astronomical opinion, but I find since
their publication that some astronomers have already shown considerable
readiness to adopt them. In my case this view of the solar constitution
of the larger planets is not a matter of mere opinion, or guessing,
or probability, but it follows of necessity, and as stated on page
200, “the great mystery of Saturn’s rings is resolved into a simple
consequence, a demonstrable and necessary result of the operation of
the familiar forces, whose laws of action have been demonstrated here
upon the earth by experimental investigation in our laboratories.
No strained hypotheses of imaginary forces are required, no ethers
or other materials are demanded, beyond those which are beneath our
feet and around our heads here upon our own planet; all that is
necessary is to grant that the well-known elements and compounds of the
chemist, and the demonstrated forces of the experimental physicist,
exist and operate in the places, and have the quantities and modes
of distribution described by the astronomer; this simple postulate
admitted, these wondrous appendages spring into rational existence, and
like the eternal fires of the sun, the barren surface of the moon, the
dry valleys of Mercury, the hazy equivocations of Venus, the seas and
continents and polar glaciers of Mars, and the cloud-covered face of
Jupiter, follow as necessary consequences of an universal atmosphere.”
If I am right in ascribing a gaseous condition to the sun and the
larger planets, and tracing the maintenance of this condition to the
disturbing gravitation of the attendant planets or satellites, a
solution of the riddle of the nebulæ at once presents itself. We have
only to suppose a star cluster or group composed of orbs of solar or
great planetary dimensions, and that these act mutually upon each
other as the planets on our sun, or the satellites upon Saturn, but
in a far more violent degree owing to the far greater relative masses
of the reacting elements, and we obtain the conditions under which
great gaseous orbs would be not merely pitted on their surface, but
riven to their very centres, moulded and shaped throughout by the
whirling hurricane of their whole substance. When thus in the centre of
a tornado of opposing gravitations the tortured orb would be twisted
bodily into a huge vorticose crater, into the bowels of which the
aqueous vapor would be dragged and dissociated, and then, entangled
with the inner matter of the riven sphere, would be hurled upwards,
again to burst forth in an explosion of such magnitude that the
original body would be measurably presented as a mere appendage, the
rocket case of the flood of fire it had vomited forth.
The reader must complete the picture. If he will take a little trouble
in doing so he will find that it becomes a portrait of one or the other
of the nebulæ, according to the kind of intergravitating star-cluster
from which he starts. I have endeavored to work out some of the details
of the nebular conditions in Chapter xx. In Chapter xxi. I have
concluded by showing the analogy between a sun and the hydro-electric
machine, the sun being the cylinder and the prominences the steam
jets. If issuing jets of high-pressure steam have the same properties
at a distance of 93 millions of miles from the earth as upon its
surface, the body of the sun and the issuing steam must be in opposite
electrical conditions, and furious electrical excitation must result;
and if the laws of electrical induction are constant throughout the
universe, the earth must be as necessarily subject to solar electrical
influence as to his thermal radiations. Thus the same reasoning which
explains the origin and maintenance of the solar heat and light,
the sun-spots, the photosphere, the chromosphere, the sierra, the
prominences, the zodiacal light, the aerolites and asteroids; the
meteorology of the planets and the rings of Saturn, also shows how the
electrical disturbances which produce the aurora borealis and direct
the needle may originate.
Electrical theories of the corona and zodiacal light, and their
connection of some kind with the aurora borealis, have been put
forth in many shapes, but so far as I have learned none afford any
explanation of the _origin_ of the electrical disturbance. Without this
they are like the vortices of Descartes, which explained the movements
of the planets by supposing another kind of motion still more
incomprehensible.
Explanations which are more difficult to explain than the phenomena
they propose to elucidate only obscure the light of true science, and
stand as impedimente to the progress of sound philosophy.
DR SIEMENS’ THEORY OF THE SUN.
A paper was read on March 2, 1882, by Dr. C. W. Siemens at the Royal
Society, and he published an article on “A New Theory of the Sun” in
the April number of the _Nineteenth Century_. All who have read my
essay on “The Fuel of the Sun” are surprised at the statement with
which the magazine article opens, viz.: that this “may be termed a
first attempt to open for the sun a debtor and creditor account,
inasmuch as he has hitherto been regarded only as a great almoner
pouring forth incessantly his boundless wealth of heat, without
receiving any of it back.”
Some of my friends suppose that Dr. Siemens has wilfully ignored the
most important element of my theory, and have suggested indignation
and protest on my part. I am quite satisfied, however, that they are
mistaken. I see plainly enough that although Dr. Siemens quotes my
book, he had not read it when he did so; that in stating that “Grove,
Humboldt, Zoellner, and Mattieu Williams have boldly asserted the
existence of a space filled with matter,” he derived this information
from the paper of Dr. Sterry Hunt which he afterward quotes. This
inference has been confirmed by subsequent correspondence with Dr.
Siemens, who tells me that he saw the book some years since but _had
not read it_. My contributions to the philosophy of solar physics would
have been far more widely known and better appreciated had I followed
the usual course of announcing firstly “a working hypothesis,” to
warn others off the ground, then reading a preliminary paper, then
another and another, and so on during ten or a dozen years, instead of
publishing all at once an octavo volume of 240 pages, which has proved
too formidable even to many of those who are specially interested in
the subject.
I am compelled to infer that this is the reason why so many of the
speculations, which were physical heresies when expounded therein,
have since become so generally adopted, without corresponding
acknowledgment. This is not the place for specifying the particulars of
such adoptions, but I may mention that in due time “An Appendix to the
Fuel of the Sun,” including the whole history of the subject, will be
published. The materials are all in hand, and only await arrangement.
In the meantime I will briefly state some of the points of agreement
and difference between Dr. Siemens and myself.
In the first place, we both take as our fundamental basis of
speculation the idea of an universal extension of atmospheric
matter, and we both regard this as the recipient of the diffused
solar radiations, which are afterwards recovered and recondensed, or
concentrated. Thus our “fuel of the sun” is primarily the same, but, as
will presently be seen, our machinery for feeding the solar furnace is
essentially different.
Certain desiccated pedants have sneered at my title, “The Fuel of the
Sun,” as “sensational,” and have refused to read the book on this
account; but Dr. Sterry Hunt has provided me with ample revenge.
He has disentombed an interesting paper by Sir Isaac Newton, dated
1675, in which the same sensationalism is perpetrated with very small
modification, Sir Isaac Newton’s title being “Solary Fuel.” Besides
this, his speculations are curiously similar to my own, his fundamental
idea being evidently the same, but the chemistry of his time was too
vague and obscure to render its development possible. This paper was
neglected and set aside, was not printed in the Transactions of the
Royal Society, and remained generally unknown till a few months ago,
when the energetic American philosopher brought it forth, and discussed
its remarkable anticipations.
Dr. Siemens supposes that the rotation of the sun effects a sort of
“fan action,” by throwing off heated atmospheric matter from his
equatorial regions, which atmospheric matter is afterwards reclaimed
and passed over to the polar regions of the sun. This interchange he
describes as effected by the differences of pressure on the fluid
envelope of the sun; the portion over the polar regions being held
down by the whole force of solar gravitation, while the equatorial
atmosphere is subject to this pressure, or attraction, minus the
centrifugal impulse due to solar rotation. He maintains that this
“centrifugal action, however small in amount as compared with the
enormous attraction of the sun, would destroy the balance, and
determine a motion towards the sun as regards the mass opposite the
polar surface, and into space as regards the equatorial mass.” He
adds that “the equatorial current so produced, owing to its mighty
proportions, would flow outwards into space, to a practically unlimited
distance.”
I will not here discuss the dynamics of this hypothesis; whether the
reclaiming action of the superior polar attraction would occur at the
vast distances from the sun supposed by Dr. Siemens, or much nearer
home, and produce an effect like the recurving of the flame of his
own regenerative gas-burner; or, whether he is right in comparing the
centrifugal force at the solar equator with that of the earth, by
simply measuring the relative velocity of translation irrespective of
angular velocity. I will merely suggest that in discussing these, it
is necessary, in order to do justice to Dr. Siemens, to always keep in
mind the assumed condition of an universal and continuous atmospheric
medium, and not to reason, as some have done already, upon the basis
of a limited solar atmosphere with a definite boundary, from beyond
which particles of atmospheric matter are to be flung away into vacuous
space, without the intervention of all-pervading fluid pressure.
It is evident that _if_ such fan action can bring back _all_ the
material that has received the solar radiations, and which holds them
either as temperature or otherwise, the restoration and perpetuation of
solar energy will be complete, for even the heat received by our earth
and its brother and sister planets would still remain in the family,
as they would radiate it into the interplanetary atmospheric matter
supposed to be reclaimed by the sun.
But, as Mr. Proctor has clearly shown, the rays of the sun cannot do
all the work thus required for his own restoration without becoming
extinguished as regards the outside universe; and if the other
suns—_i.e._, the stars—do the same they could not be visible to us.
Thus Dr. Siemens’ theory removes our sun from his place among the
stars, and renders the great problem of stellar radiation more
inscrutable than ever by thus putting the evidence of our great
luminary altogether out of court.
My theory, on the contrary, demands only a gradual absorption of solar
and stellar rays, such as actual observation of their varying splendor
indicates.
If space were absolutely transparent, and its infinite depths peopled
throughout, the firmament would present to our view one continuous
blazing dome, as all the spaces between the nearer stars would be
filled by the infinity of radiations from the more distant.
ANOTHER WORLD DOWN HERE.
What a horrible place must this world appear when regarded according
to our ideas from an insect’s point of view! The air infested with
huge flying hungry dragons, whose gaping and snapping mouths are ever
intent upon swallowing the innocent creatures for whom, according to
the insect, if he were like us, a properly constructed world ought
to be exclusively adapted. The solid earth continually shaken by the
approaching tread of hideous giants—moving mountains—that crush out
precious lives at every footstep, an occasional draught of the blood of
these monsters, stolen at life-risk, affording but poor compensation
for such fatal persecution.
Let us hope that the little victims are less like ourselves than the
doings of ants and bees might lead us to suppose; that their mental
anxieties are not proportionate to the optical vigilance indicated by
the four thousand eye-lenses of the common house-fly, the seventeen
thousand of the cabbage butterfly and the wide-awake dragon-fly, or
the twenty-five thousand possessed by certain species of still more
vigilant beetles.
Each of these little eyes has its own cornea, its lens, and a curious
six-sided, transparent prism, at the back of which is a special retina
spreading out from a branch of the main optic nerve, which, in the
cockchafer and some other creatures, is half as large as the brain. If
each of these lenses forms a separate picture of each object rather
than a single mosaic picture, as some anatomists suppose, what an awful
army of cruel giants must the cockchafer behold when he is captured by
a schoolboy!
The insect must see a whole world of wonders of which we know little
or nothing. True, we have microscopes, with which we can see one thing
at a time if carefully laid upon the stage; but what is the finest
instrument that Ross can produce compared to that with twenty-five
thousand object-glasses, all of them probably achromatic, and each one
a living instrument, with its own nerve-branch supplying a separate
sensation? To creatures thus endowed with microscopic vision, a cloud
of sandy dust must appear like an avalanche of massive rock-fragments,
and everything else proportionally monstrous.
One of the many delusions engendered by our human self-conceit and
habit of considering the world as only such as we know it from our
human point of view, is that of supposing human intelligence to be
the only kind of intelligence in existence. The fact is, that what we
call the lower animals have special intelligence of their own as far
transcending our intelligence as our peculiar reasoning intelligence
exceeds theirs. We are as incapable of following the track of a friend
by the smell of his footsteps as a dog is of writing a metaphysical
treatise.
So with insects. They are probably acquainted with a whole world of
physical facts of which we are utterly ignorant. Our auditory apparatus
supplies us with a knowledge of sounds. What are these sounds? They
are vibrations of matter which are capable of producing corresponding
or sympathetic vibrations of the drums of our ears or the bones of our
skull. When we carefully examine the subject, and count the number
of vibrations that produce our world of sounds of varying pitch, we
find that the human ear can only respond to a limited range of such
vibrations. If they exceed three thousand per second, the sound becomes
too shrill for average people to hear it, though some exceptional ears
can take up pulsations or waves that succeed each other more rapidly
than this.
Reasoning from the analogy of stretched strings and membranes, and of
air vibrating in tubes, etc., we are justified in concluding that the
smaller the drum or the tube the higher will be the note it produces
when agitated, and the smaller and the more rapid the aerial wave
to which it will respond. The drums of insect ears, and the tubes,
etc., connected with them, are so minute that their world of sounds
probably begins where ours ceases; that the sound which appears to
us as continuous is to them a series of separated blows, just as
vibrations of ten to twelve per second appear to us. We begin to hear
such vibrations as continuous sounds when they amount to about thirty
per second. The insect’s continuous sound probably begins beyond three
thousand. The blue-bottle may thus enjoy a whole world of exquisite
music of which we know nothing.
There is another very suggestive peculiarity in the auditory apparatus
of insects. Its structure and position are something between those of
an ear and of an eye. Careful examination of the head, of one of our
domestic companions—the common cockroach or black-beetle—will reveal
two round white points, somewhat higher than the base of the long outer
antennæ, and a little nearer to the middle line of the head. These
white projecting spots are formed by the outer transparent membrane
of a bag or ball filled with fluid, which ball or bag rests inside
another cavity in the head. It resembles our own eye in having this
external transparent tough membrane, which corresponds to the cornea
or transparent membrane forming the glass of our eye-window; which,
like the cornea, is backed by the fluid in an ear-ball corresponding
to our eye-ball, and the back of this ear-ball appears to receive the
outspreadings of a nerve, just as the back of our eye is lined with
that outspread of the optic nerve forming the retina. There does not
appear to be in this or other insects a tightly stretched membrane
which, like the membrane of our ear-drum, is fitted to take up bodily
air-waves and vibrate responsively to them. But it is evidently adapted
to receive and concentrate some kind of vibration, or motion, or tremor.
What kind of motion can this be? What kind of perception does this
curious organ supply? To answer these questions we must travel beyond
the strict limits of scientific induction and enter the fairyland of
scientific imagination. We may wander here in safety, provided we
always remember where we are, and keep a true course guided by the
compass-needle of demonstrable facts.
I have said that the cornea-like membrane of the insect’s ear-bag does
not appear capable of responding to _bodily_ air-waves. This adjective
is important, because there are vibratory movements of matter that
are not bodily but molecular. An analogy may help to render this
distinction intelligible. I may take a long string of beads and shake
it into wavelike movements, the waves being formed by the movements
of the whole string. We may now conceive another kind of movement or
vibration by supposing one bead to receive a blow pushing it forward,
this push to be communicated to the next, then to the third, and so on,
producing a minute running tremor passing from end to end. This kind of
action may be rendered visible by laying a number of billiard balls or
marbles in line and bowling an outside ball against the end one of the
row. The impulse will be rapidly and invisibly transmitted all along
the line, and the outer ball will respond by starting forward.
Heat, light, and electricity are mysterious internal movements of what
we call matter (some say “ether,” which is but a name for imaginary
matter). These internal movements are as invisible as those of the
intermediate billiard balls; but if there be a line of molecules acting
thus, and the terminal one strikes an organ of sense fitted to receive
its motion, some sort of perception may follow. When such movements
of certain frequency and amplitude strike our organs of vision, the
sensation of light is produced. When others of greater amplitude and
smaller frequency strike the terminal outspread of our common sensory
nerves, the sensation of heat results. The difference between the
frequency and amplitude of the heat waves and the light waves is but
small, or, strictly speaking, there is no actual line of separation
lying between them; they run directly into each other. When a piece
of metal is gradually heated, it is first “black-hot;” this is while
the waves or molecular tremblings are of a certain amplitude and
frequency; as the frequency increases and amplitude diminishes (or, to
borrow from musical terms, as the pitch rises), the metal becomes dull
red-hot; greater rapidity, cherry red; greater still, bright red; then
yellow-hot and white-hot: the luminosity growing as the rapidity of
molecular vibration increases.
There is no such gradation between the most rapid undulations or
tremblings that produce our sensation of sound and the slowest of those
which give rise to our sensations of gentlest warmth. There is a huge
gap between them, wide enough to include another world or several other
worlds of motion, all lying between our world of sounds and our world
of heat and light, and there is no good reason whatever for supposing
that matter is incapable of such intermediate activity, or that such
activity may not give rise to intermediate sensations, provided there
are organs for taking up and sensifying (if I may coin a desirable
word) these movements.
As already stated, the limit of audible tremors is three to four
thousand per second, but the smallest number of tremors that we can
perceive as heat is between three and four millions of millions
per second. The number of waves producing red light is estimated
at four hundred and seventy-four millions of millions per second;
and for the production of violet light, six hundred and ninety-nine
millions of millions. These are the received conclusions of our best
mathematicians, which I repeat on their authority. Allowing, however, a
very large margin of possible error, the world of possible sensations
lying between those produced by a few thousands of waves and any number
of millions is of enormous width.
In such a world of intermediate activities the insect probably lives,
with a sense of vision revealing to him more than our microscopes
show to us, and with his minute eye-like ear-bag sensifying material
movements that lie between our world of sounds and our other
far-distant worlds of heat and light.
There is yet another indication of some sort of intermediate
sensation possessed by insects. Many of them are not only endowed
with the thousands of lenses of their compound eyes, but have in
addition several curious organs that have been designated “ocelli”
and “stemmata.” These are generally placed at the top of the head,
the thousand-fold eyes being at the sides. They are very much like
the auditory organs above described—so much so that in consulting
different authorities for special information on the subject I have
fallen into some confusion, from which I can only escape by supposing
that the organ which one anatomist describes as the ocelli of certain
insects is regarded as the auditory apparatus when examined in another
insect by another anatomist. All this indicates a sort of continuity of
sensation connecting the sounds of the insect world with the objects of
their vision.
But these ocular ears or auditory eyes of the insect are not his only
advantage over us. He has another sensory organ to which, with all our
boasted intellect, we can claim nothing that is comparable, unless
it be our olfactory nerve. The possibility of this I will presently
discuss.
I refer to the _antennæ_, which are the most characteristic of insect
organs, and wonderfully developed in some, as may be seen by examining
the plumes of the crested gnat. Everybody who has carefully watched
the doings of insects must have observed the curiously investigative
movements of the antennæ, which are ever on the alert, peering and
prying to right and left and upwards and downwards. Huber, who devoted
his life to the study of bees and ants, concluded that these insects
converse with each other by movements of the antennæ, and he has given
to the signs thus produced the name of “antennal language.” They
certainly do communicate information or give orders by some means;
and when the insects stop for that purpose, they face each other and
execute peculiar wavings of these organs that are highly suggestive of
the movements of the old semaphore telegraph arms.
The most generally received opinion is that these antennæ are very
delicate organs of touch, but some recent experiments made by Gustav
Hansen indicate that they are organs of smelling or of some similar
power of distinguishing objects at a distance. Flies deprived of
their antennæ ceased to display any interest in tainted meat that had
previously proved very attractive. Other insects similarly treated
appear to become indifferent to odors generally. He shows that the
development of the antennæ in different species corresponds to the
power of smelling which they seem to possess.
I am sorely tempted to add another argument to those brought forward by
Hansen, viz.: that our own olfactory nerves, and those of all our near
mammalian relations, are curiously like a pair of antennæ.
There are two elements in a nervous structure—the gray and the white;
the gray, or ganglionic portion, is supposed to be the centre or seat
of nervous power, and the white medullary or fibrous portion merely the
conductor of nervous energy.
The nerves of the other senses have their ganglia seated internally,
and bundles of tubular white threads spread outwards therefrom; but not
so with the olfactory nervous apparatus. These present two horn-like
projections that are thrust forward from the base of the brain, and
have white or medullary stems that terminate outwardly or anteriorly
in ganglionic bulbs resting upon what I may call the roof of the nose;
these bulbs throw out fibres that are composed, rather paradoxically,
of more gray matter than white. In some quadrupeds with great power of
smell, the olfactory nerves extend so far forward as to protrude beyond
the front of the hemispheres of the brain, with bulbous terminations
relatively very much larger than those of man.
They thus appear like veritable antennæ. In some of our best works
on anatomy of the brain (Solly, for example) a series of comparative
pictures of the brains of different animals is shown, extending from
man to the cod-fish. As we proceed downwards, the horn-like projection
of the olfactory nerves beyond the central hemispheres goes on
extending more and more, and the relative magnitude of the terminal
ganglia or olfactory lobes increases in similar order.
We have only to omit the nasal bones and nostrils, to continue
this forward extrusion of the olfactory nerves and their bulbs and
branches, to coat them with suitable sheaths provided with muscles for
mobility, and we have the antennæ of insects. I submit this view of the
comparative anatomy of these organs as my own speculation, to be taken
for what it is worth.
There is no doubt that the antennæ of these creatures are connected by
nerve-stalks with the anterior part of their supra-œsophageal ganglia,
_i.e._, the nervous centres corresponding to our brain.
But what kind and degree of power must such olfactory organs possess?
The dog has, relatively to the rest of his brain, a much greater
development of the olfactory nerves and ganglia than man has. His
powers of smell are so much greater than ours that we find it difficult
to conceive the possibility of what we actually see him do. As an
example, I may describe an experiment I made upon a bloodhound of the
famous Cuban breed. He belonged to a friend whose house is situated on
an eminence commanding an extensive view. I started from the garden and
wandered about a mile away, crossed several fields by sinuous courses,
climbing over stiles, and jumping ditches, always keeping the house
in view; I then returned by quite a different track. The bloodhound
was set upon the beginning of my track. I watched him from a window
galloping rapidly, and following all its windings without the least
halting or hesitation. It was as clear to his nose as a gravelled path
or a luminous streak would be to our eyes. On his return I went down
to him, and without approaching nearer than five or six yards, he
recognized me as the object of his search, proving this by circling
round me, baying deeply and savagely though harmlessly, as he always
kept at about the same distance.[8]
If the difference of development between the human and canine internal
antennæ produces all this difference of function, what a gulf may there
be between our powers of perceiving material emanations and those
possessed by insects! If my anatomical hypothesis is correct, some
insects have protruding nasal organs or out-thrust olfactory nerves as
long as all the rest of their bodies. The power of movement of these
in all directions affords the means of sensory communication over a
corresponding range, instead of being limited merely to the direction
of the nostril openings. In some insects, such as the plumed gnat, the
antennæ do not appear to be thus moveable, but this want of mobility
is more than compensated by the multitude of branchings of these
wonderful organs, whereby they are simultaneously exposed in every
direction. This structure is analogous to the fixed but multiplied eyes
of insects, which, by seeing all round at once, compensate for the want
of that mobility possessed by others that have but a single eyeball
mounted on a flexible and mobile stalk; that of the spider, for example.
Such an extension of such a sensory function is equivalent to living
in another world of which we have no knowledge and can form no
definite conception. We, by our senses of touch and vision, know the
shapes and colors of objects, and by our very rudimentary olfactory
organs form crude ideas of their chemistry or composition, through
the medium of their material emanations; but the huge exaggeration of
this power in the insect should supply him with instinctive perceptive
powers of chemical analysis, a direct acquaintance with the inner
molecular constitution of matter far clearer and deeper than we are
able to obtain by all the refinements of laboratory analyses or the
hypothetical formulating of molecular mathematicians. Add this to the
other world of sensations producible by the vibratory movements of
matter lying between those perceptible by our organs of hearing and
vision, then strain your imagination to its cracking point, and you
will still fail to picture the wonderland in which the smallest of our
fellow-creatures may be living, moving, and having their being.
THE ORIGIN OF LUNAR VOLCANOES.
Many theoretical efforts, some of considerable violence, have been
made to reconcile the supposed physical contradiction presented by
the great magnitude and area of former volcanic activity of the Moon,
and the present absence of water on its surface. So long as we accept
the generally received belief that water is a necessary agent in the
evolution of volcanic forces, the difficulties presented by the lunar
surface are rather increased than diminished by further examination and
speculation.
We know that the lava, scoriæ, dust and other products of volcanic
action on this earth are mainly composed of mixed silicates—those of
alumina and lime preponderating. When we consider that the solid crust
of the Earth is chiefly composed of silicic acid, and of basic oxides
and carbonates which combine with silicic acid when heated, a natural
necessity for such a composition of volcanic products becomes evident.
If the Moon is composed of similar materials to those of the Earth, the
fusion of its crust must produce similar compounds, as they are formed
independently of any atmospheric or aqueous agency.
This being the case, the phenomena presented by the cooling of
fused masses of mixed silicates in the absence of water become very
interesting. Opportunities of studying such phenomena are offered at
our great iron-works, where fused masses of iron cinder, composed
mainly of mixed silicates, are continually to be seen in the process of
cooling under a variety of circumstances.
I have watched the cooling of such masses very frequently, and have
seen abundant displays of miniature volcanic phenomena, especially
marked where the cooling has occurred under conditions most nearly
resembling those of a gradually cooling planet or satellite; that
is, when the fused cinder has been enclosed by a solid resisting and
contracting crust.
The most remarkable that I have seen are those presented by the cooling
of the “tap cinder” from puddling furnaces. This, as it flows from the
furnace, is received in stout iron boxes (“cinder-bogies”) of circular
or rectangular horizontal section. The following phenomena are usually
observable on the cooling of the fused cinder in a circular bogie.
First a thin solid crust forms on the red-hot surface. This speedily
cools sufficiently to blacken. If pierced by a slight thrust from
an iron rod, the red-hot matter within is seen to be in a state of
seething activity, and a considerable quantity exudes from the opening.
If a bogie filled with fused cinder is left undisturbed, a veritable
spontaneous volcanic eruption takes place through some portion,
generally near the centre, of the solid crust. In some cases, this
eruption is sufficiently violent to eject small spurts of molten cinder
to a height equal to four or five diameters of the whole mass.
The crust once broken, a regular crater is rapidly formed, and
miniature streams of lava continue to pour from it; sometimes slowly
and regularly, occasionally with jerks and spurts due to the bursting
of bubbles of gas. The accumulation of these lava-streams forms a
regular cone, the height of which goes on increasing. I have seen a
bogie about 10 or 12 inches in diameter, and 9 or 10 inches deep,
thus surmounted by a cone above 5 inches high, with a base equal to
the whole diameter of the bogie. These cones and craters could be but
little improved by a modeler desiring to represent a typical volcano in
miniature.
Similar craters and cones are formed on the surface of cinder which is
not confined by the sides of the bogie. I have seen them well displayed
on the “running-out beds” of refinery furnaces. These, when filled,
form a small lake of molten iron covered with a layer of cinder. This
cinder first skins over, as in the bogies, then small crevasses form in
this crust, and through these the fused cinder oozes from below. The
outflow from this chasm soon becomes localized, so as to form a single
crater, or a small chain of craters; these gradually develop into cones
by the accumulation of outflowing lava, so that when the whole mass has
solidified, it is covered more or less thickly with a number of such
hillocks. These, however, are much smaller than in the former case,
reaching to only one or two inches in height, with a proportionate
base. It is evident that the dimensions of these miniature volcanoes
are determined mainly by the depth of the molten matter from which
they are formed. In the case of the bogies, they are exaggerated by
the overpowering resistance of the solid iron bottom and sides, which
force all the exudation in the one direction of least resistance, viz.,
towards the centre of the thin upper crust, and thus a single crater
and a single cone of the large relative dimensions above described are
commonly formed.
The magnitude and perfection of these miniature volcanoes vary
considerably with the quality of the pig-iron and the treatment it
has received, and the difference appears to depend upon the evolution
of gases, such as carbonic oxide, volatile chlorides, fluorides, etc.
I mention the fluorides particularly, having been recently engaged
in making some experiments on Mr. Henderson’s process for refining
pig-iron, by exposing it when fused to the action of a mixture of
fluoride of calcium and oxides of iron, alumina, manganese, etc. The
cinder separated from this iron displayed the phenomena above described
very remarkably, and jets of yellowish flame were thrown up from the
craters while the lava was flowing. The flame was succeeded by dense
white vapors as the temperature of the cinder lowered, and a deposit of
snow-like, flocculent crystals was left upon and around the mouth or
crater of each cone. The miniature representation of cosmical eruptions
was thus rendered still more striking, even to the white deposit of the
haloid salts which Palmieri has described as remaining after the recent
eruption of Vesuvius.
The gases thus evolved have not yet been analytically examined, and
the details of the powerful reactions displayed in this process still
demand further study; but there can be no doubt that the combination
of silicic acid with the base of the fluor spar is the fundamental
reaction to which the evolution of the volatile fluorides, etc., is
mainly due.
A corresponding evolution of gases takes place in cosmical volcanic
action, whenever silicic acid is fused in contact with limestone or
other carbonate, and a still closer analogy is presented by the fusion
of silicates in contact with chlorides and oxides, in the absence of
water. If the composition of the Moon is similar to that of the Earth,
chlorides of sodium, etc., must form an important part of its solid
crust; they should correspond in quantity to the great deposit of
such salts that would be left behind if the ocean of the Earth were
evaporated to dryness. The only assumptions demanded in applying these
facts to the explanation of the surface configuration of the Moon are,
1st, that our satellite resembles its primary in chemical composition;
2d, that it has cooled down from a state of fusion; and 3d, that the
magnitude of the eruptions, due to such fusion and cooling, must bear
some relation to the quantity of matter in action.
The first and second are so commonly made and understood, that I need
not here repeat the well-known arguments upon which they are supported,
but may remark that the facts above described afford new and weighty
evidence in their favor.
If the correspondence between the form of a freely suspended and
rotating drop of liquid and that of a planet or satellite is accepted
as evidence of the exertion of the same forces of cohesion, etc.,
on both, the correspondence between the configuration of the lunar
surface, and that of small quantities of fused and freely cooled
earth-crust matter, should at least afford material support to the
otherwise indicated inference, that the materials of the Moon’s crust
are similar to those of the Earth’s, and that they have been cooled
from a state of fusion.
I think I may safely generalize to the extent of saying, that no
considerable mass of fused earthy silicates can cool down under
circumstances of free radiation without first forming a heated solid
crust, which, by further radiation, cooling, and contraction, will
assume a surface configuration resembling more or less closely that of
the Moon. Evidence of this is afforded by a survey of the spoil-banks
of blast furnaces, where thousands of blocks of cinder are heaped
together, all of which will be found to have their upper surfaces (that
were freely exposed when cooling) corrugated with radiating miniature
lava streams, that have flowed from one or more craters or openings
that have been formed in the manner above described.
The third assumption will, I think, be at once admitted, inasmuch as it
is but the expression of a physical necessity.
According to this, the Earth, if it has cooled as the Moon is supposed
to have done, should have displayed corresponding irregularities,
and generally, the magnitude of mountains of solidified planets and
satellites should be on a scale proportionate to their whole mass.
In comparing the mountains of the Moon and _Mercury_ with those of
the Earth, a large error is commonly made by taking the customary
measurements of terrestrial mountain-heights from the sea-level. As
those portions of the Earth which rise above the waters are but its
upper mountain slopes, and the ocean bottom forms its lower plains
and valleys, we must add the greatest ocean depths to our customary
measurements, in order to state the full height of what remains of the
original mountains of the Earth. As all the stratified rocks have been
formed by the wearing down of the original upper slopes and summits, we
cannot expect to be able to recognize the original skeleton form of our
water-washed globe.
If my calculation of the atmosphere of _Mercury_ is correct, viz.,
that its pressure is equal to about one seventh of the Earth’s, or
4¼ inches of mercury, there can be no liquid water on that planet,
excepting perhaps over a small amount of circumpolar area, and during
the extremes of its aphelion winter. Thus the irregularities of the
terminator, indicating mountain elevations calculated to reach to
1/253 of the diameter of the planet, are quite in accordance with the
above-stated theoretical consideration.
There is one peculiar feature presented by the cones of the cooling
cinder which is especially interesting. The flow of fused cinder
from the little crater is at first copious and continuous; then it
diminishes and becomes alternating, by a rising and falling of the
fused mass within the cone. Ultimately the flow ceases, and then the
inner liquid sinks, more or less, below the level of the orifice. In
some cases, where much gas is evolved, this sinking is so considerable
as to leave the cone as a mere hollow shell; the inner liquid having
settled down and solidified with a flat or slightly rounded surface, at
about the level of the base of the cone, or even lower. These hollow
cones were remarkably displayed in some of the cinder of the Henderson
iron, and their formation was obviously promoted by the abundant
evolution of gas.
If such hollow cones were formed by the cooling of a mass like that
of the Moon, they would ultimately and gradually subside by their own
weight. But how would they yield? Obviously by a gradual hinge-like
bending at the base towards the axis of the cone. This would occur
with or without fracture, according to the degree of viscosity of the
crust, and the amount of inclination. But the sides of the hollow-cone
shell, in falling towards the axis, would be crushing into smaller
circumferences. What would result from this? I think it must be the
formation of fissures, extending, for the most part, radially from the
crater towards the base, and a crumpling up of the shell of the cone by
foldings in the same direction. Am I venturing too far in suggesting
that in this manner may have been formed the mysterious rays and rills
that extend so abundantly from several of the lunar craters?
The upturned edges or walls of the broken crust, and the chasms
necessarily gaping between them, appear to satisfy the peculiar
phenomena of reflection which these rays present. These edges of the
fractured crust would lean towards each other, and form angular chasms;
while the foldings of the crust itself would form long concave troughs,
extending radially from the crater.
These, when illuminated by rays falling upon them in the direction of
the line of vision, must reflect more light towards the spectator than
does the general convex lunar surface, and thus they become especially
visible at the full Moon.
Such foldings and fractures would occur after the subsidence and
solidification of the lava-forming liquid—that is, when the formation
of new craters had ceased in any given region; hence they would extend
across the minor lateral craters formed by outbursts from the sides of
the main cone, in the manner actually observed.
The fact that the bottoms of the great walled craters of the Moon are
generally lower than the surrounding plains must not be forgotten in
connection with this explanation.
I will not venture further with the speculations suggested by the
above-described resemblances, as my knowledge of the details of the
telescopic appearances of the Moon is but second-hand. I have little
doubt, however, that observers who have the privilege of direct
familiarity with such details, will find that the phenomena presented
by the cooling of iron cinder, or other fused silicates, are worthy of
further and more careful study.
NOTE ON THE DIRECT EFFECT OF SUN-SPOTS ON TERRESTRIAL CLIMATES.
Professor Langley determines quantitatively the effects respectively
produced by the radiations from the solar spots, penumbra, and
photosphere upon the face of a thermopile, and infers that these
effects measure their relative influence on terrestrial climate.
In thus assuming that the heat communicated to the thermopile measures
the solar contribution to terrestrial climate, Professor Langley omits
an important factor, viz., the amount of heat absorbed in traversing
the earth’s atmosphere; and in measuring the relative efficiency of
the spots, penumbra, and photosphere, he has not taken into account
the variations of diathermancy of the intervening atmospheric matter,
which are due to the variations in the source of heat.
Speaking generally, it may be affirmed that the radiations of obscure
heat are more largely absorbed by the gases and vapors of our
atmosphere than those of luminous heat, and the great differences in
the mere luminosity of the spots, penumbra, and photosphere justify
the assumption that the radiations of a sun-spot will (to use the
expressive simile of Tyndall) lose far more by atmospheric sifting than
will those from the photosphere.
But the spot areas will be none the less effective on terrestrial
climate on that account. A given amount of heat arrested by the earth’s
atmosphere will have even greater climatic efficiency than if received
upon its solid surface, inasmuch as the gases are worse radiators than
the rocks, and will therefore, _cæteris paribus_, retain a larger
proportion of the heat they receive.
I have long ago endeavored to show[9] that the depth of the
photosphere, from the solar surface inwards, is limited by
dissociation; that the materials of the Sun within the photosphere
exist in a dissociated, elementary condition; that at the photosphere
they are, for the most part, combined. This view has since been adopted
by many eminent solar physicists, and if correct, demands a much higher
temperature within the depths revealed by that withdrawal of the
photospheric veil which constitutes a sun-spot.
If I am right in this, and also in supposing the spot-radiations to be
so much more abundantly absorbed than those of the photosphere, and if
in spite of this higher temperature of the spots, the _surface_ of the
earth receives from them the lower degree of heat measured by Professor
Langley, another interesting consequence must follow. The excess of
spot-heat directly absorbed by the atmosphere, and mainly by the
water dissolved or suspended in its upper regions, must be especially
effective in dissipating clouds and checking or modifying their
formation. The meteorological results of this may be important, and are
worthy of careful study.
In thus venturing to question some of Professor Langley’s inferences I
am far from underrating the interest and importance of his researches.
On the contrary, I regard the quantitative results he has obtained
as especially valuable and opportune, in affording means of testing
the above-named and other speculations in solar physics. Similar
observations repeated at different elevations would decide, so far as
the lower regions are concerned, whether or not there is any difference
in the quantity of heat imparted by the bright and obscure portions
of the Sun to our atmosphere. If the differences already observed by
Professor Langley vary in ascending, a new means will be afforded of
studying the constitution of the interior of the Sun and its relations
to the photosphere. Direct evidence of selective absorption by our
atmosphere may thus be obtained, which would go far towards solving one
of the crucial solar problems, viz., whether the darker regions are
hotter or cooler than the photosphere.
The obscure radiations from the moon must be absorbed by our atmosphere
like those from the sun-spot, and may be sufficiently effective to
account for the alleged dissipation of clouds by the full moon.
In both cases the climatic influence is greatly heightened by the fact
that all the heat thus absorbed is directly effective in raising the
temperature of the air. The action of the absorbed heat in reference
to cloud-formation is directly opposite to that of the transmitted
solar heat, as this reaching the surface of the earth evaporates the
superficial water, and thereby produces the material of clouds. On
the other hand, the heat which is absorbed by the air increases its
vapor-holding capacity, and thus prevents the formation of clouds, or
even effects the dissolution of clouds already formed.
THE PHILOSOPHY OF THE RADIOMETER AND ITS COSMICAL REVELATIONS.
So much speculation, and not a little extravagant speculation, has been
devoted to the dynamics of the radiometer, that I feel some compunction
in adding another stone to the heap, my only apology and justification
for so doing being that I propose to regard the subject from a very
unsophisticated point of view, and with somewhat heretical directness
of vision—_i.e._, quite irrespective of atoms, molecules, or ether,
or any other specific preconceptions concerning the essential kinetics
of radiant forces, beyond that of regarding such forces as affections
or conditions of matter which are transmitted radially in constant
quantity, and therefore obey the necessary law of radial diffusion or
inverse squares.
The primary difficulty which appears to have generally been suggested
by the movements of the radiometer, is the case which it seems to
present of mechanical action without any visible basis of corresponding
reaction: a visible tangible object pushed forward, without any visible
pushing agent or resisting fulcrum against which the moving body reacts.
This difficulty has been met by the invocation of obedient and
vivacious molecules of residual atmospheric matter, which have been
called upon to bound and rebound between the vanes and the inner
surfaces of the glass envelope of the instrument.
How is it that the advocates of these activities have not sought to
verify their speculations by modifying the shape and dimensions of the
exhausted glass bulb or receiver?[10] If the motion of the radiometer
is due to such excursions and collisions, the length of excursion and
the angles of collision must modify its motions; and such modification
under given conditions would form a fine subject for the exercise of
the ingenuity of molecular mathematicians. If their hypothetical data
are sound, they should be able to predict the relative velocities or
torsion-force of a series of radiometers of similar construction in all
other respects, but with variable shapes and diameters of enclosing
vessels.
If we divest our minds of all visions of hypothetical atoms, molecules,
ethers, etc., and simply look at the facts of radiation with the
same humility of intellect as we usually regard gravitation, this
primary difficulty of the radiometer at once vanishes. The force
of gravitation is a radiant force acting somehow between, or upon,
or by distant bodies; and these bodies, however far apart, act and
react upon each other with mutual forces, precisely equal and exactly
contrary. We conceive the sun pulling the earth in a certain direction,
and receiving from the earth an equal pull in a precisely contrary
direction, and we have hitherto demanded no ethereal or molecular link
for the transmission of these mutually attractive forces. Why, then,
should we not regard radiant repulsive energy in the same simple manner?
If we do this there is no difficulty in finding the ultimate reaction
fulcrum of the radiometer vanes. It is simply the radiating body, the
match, the candle, the lamp, the sun, or whatever else may be the
source of the impelling radiations. According to this view, the radiant
source must be repelled with precisely the same energy as the arms or
pendulum of the radiometer; and it would move backward or in opposite
direction if equally free to move. If, by any means, we cause the glass
envelope of the radiometer to become the radiant source, it should be
repelled, and may even rotate in opposite direction to the vanes, or
_vice versâ_. This has been done with floating radiometers.
Viewed thus as simple matter of fact, irrespective of any preconceived
kinetics of intervening media, the net result of Mr. Crookes’s
researches become nothing less than the discovery of a new law of
nature of great magnitude and the broadest possible generality, viz.,
that the sun and all other radiant bodies—_i.e._, all the materials
of the universe—exert a mechanical repulsive force, in addition to
the calorific, luminous, actinic, and electrical forces with which
they have hitherto been credited. He has shown that this force is
refrangible and dispersible, that it is outspread with the spectrum,
but is most concentrated, or active, in the region of the ultra-red
rays, and progressively feeblest in the violet; or, otherwise stated,
it exists in closer companionship with heat than with light, and closer
with light than with actinism.
According to the doctrine of exchanges, which has now passed from the
domain of theory to that of demonstrated law, all bodies, whatever be
their temperature, are perpetually radiating heat-force, the amount
of which varies, _cæteris paribus_, with their temperature. If we now
add to this generalization that all bodies are similarly radiating
mechanical force and suffering corresponding mechanical reaction, the
theoretical difficulties of the radiometer vanish. What must follow in
the case of a freely suspended body unequally heated on opposite sides?
It must be repelled in a direction perpendicular to the surface of
its hottest side. If two rockets were affixed to opposite sides of a
pendant body, and were to exert unequal ejective forces, the reaction
of the stronger rocket would repel the body in the opposite direction
to its preponderating ejection. This represents the radiometer vane
with one side blackened and the other side bright. When exposed to
luminous rays the black side becomes warmer than the bright side by
its active absorption and conversion of light into heat, and thus the
blackened face radiates in excess and recedes.
We may regard it thus as acting by its own radiations, or otherwise as
acted upon by the more powerful radiant whose rays are differentially
received by the black and bright sides. These different modes of
regarding the action are perfectly consistent with each other, and
analogous to the two different modes of regarding gravitation, when
we describe the sun as attracting the earth, or, otherwise, the
earth as gravitating to the sun. Strictly speaking, neither of these
descriptions is correct, as the gravitation is mutual, and the total
quantity exerted between the sun and the earth is equal to the sum of
their energies, but it is sometimes convenient to regard the action
from a solar standpoint, and at others from a terrestrial. So with
the radiometer and the strictly mutual repulsions between it and the
predominating radiant.
It appears to me that this unsophisticated conception of radiant
mechanical repulsive force, and its necessary mechanical reaction
on the radiant body, meets all the facts at present revealed by the
experiments of Mr. Crookes and others.
The attraction which occurs when the disc of the radiometer is
surrounded with a considerable quantity of atmospheric matter is
probably due to inequality of atmospheric pressure. The absorbing
face of the disc becomes heated above the temperature of the opposite
face, the film of air in contact with the warmer face rises, leaving
a relatively vacuous space in front. This produces a rush of air from
back to front which carries the radiometer vane with it. When the
exhaustion of the radiometer is carried so far that the residual air
is only just sufficiently dense to neutralize the direct repulsion of
radiation, the neutral point is reached. When exhaustion is carried
beyond this, repulsion predominates.
Taking Mr. Crookes’s estimate of the mechanical energy of solar
radiation at 32 grains per square foot, 2 cwts. per acre, 57 tons per
square mile, etc., and accepting these as they are offered, _i.e._,
merely as provisional and approximate estimates, we are led to a
cosmical inference of the highest importance, one that must materially
modify our interpretations of some of the grandest phenomena of the
universe. Although the estimated sunlight pressure upon the earth, the
three thousand millions of tons, is too small a fraction of the earth’s
total weight to effect an easily measurable increase of the length of
our year, the case is quite otherwise with the asteroids and the zones
of meteoric matter revolving around the sun.
The mechanical repulsion of radiation is a superficial action, and
must, therefore, vary with the amount of surface exposed, while that of
gravitation varies with the mass. Thus the ratio of radiant repulsion
to the attraction of gravitation goes on increasing with the subdivison
of masses, and becomes an important fraction in the case of the smaller
bodies of the solar system. A zone of meteorites traveling around
the sun would be broken up, sifted, and sorted into different orbits,
according to their diameters, if this superficial repulsion operated
against gravitation without any compensating agency. Gravitation would
be opposed in various degrees, neutralized, and, in the case of cosmic
dust, even reversed. Comets presenting so large a surface in proportion
to their mass would either be driven away altogether or forced to move
in orbits utterly disobedient to present calculations. This would occur
if the inter-planetary spaces were as nearly vacuous as the torsion
instrument with which Mr. Crookes made his measurements.
Regarding the properties of our atmosphere only in the light
of experimental data, irrespective of imaginary molecules, and
their supposed gyrations or oscillations, we see at once that an
inter-planetary or inter-stellar vacuum must act like a Sprengel
pump upon our atmosphere, upon the atmosphere of other planets, and
upon those of the sun and the stars, and would continue such action
until an equilibrium between the repulsive energy of the gas and the
gravitation of the solid orbs had been established. Atmospheric matter
would thus be universally diffused, with special accumulations around
solid orbs, varying in quantity with their respective gravitating
energy. Such a universal atmosphere would accelerate orbital motion,
and this acceleration would vary with the surface of bodies. Its action
being thus exactly opposed to that of radiant repulsion, it must, at a
certain density, exactly neutralize it. That it does this is evident
from the obedience of all the elements of the solar system to the
calculated action of gravitation; and thus Mr. Crookes’s researches
not only confirm the idea of universal atmospheric diffusion, but they
afford a means by which we may ultimately measure the actual density of
the universal atmosphere. If, as I have endeavored to show in my essay
on “The Fuel of the Sun,” the initial radiant energy of every star
depends upon its mass, and its consequent condensation of atmospheric
matter, the density of inter-planetary atmosphere sufficient to
neutralize the radiant mechanical energy of our sun may be the same
as is demanded to perform the same function for all the stars of the
universe, and all their attendant worlds, comets, and meteors.
In order to prevent misunderstanding of the above, I must add that I
have therein studiously assumed a negative position in reference to all
hypothetical conceptions of the nature of heat, light, etc., and their
modes of transmission, simply because I feel satisfied that the subject
has hitherto been obscured and complicated by overstrained efforts to
fit the phenomena to the excessively definite hypotheses of modern
molecular mathematicians. The atoms invented by Dalton for the purpose
of explaining the demonstrated laws of chemical combination performed
this function admirably, and had great educational value, so long as
their purely imaginary origin was kept in view; but when such atoms are
treated as facts, and physical dogmas are based upon the assumption of
their actual existence, they become dangerous physical superstitions.
Regarding matter as continuous, _i.e._, supposing it to be simply as it
appears to be, and co-extensive with the universe, in accordance with
the experimental evidences of the unlimited expansibility of gaseous
matter, we need only assume that our sensations of heat, light, etc.,
are produced by active conditions of such matter analogous to those
which are proved to produce our sensations of sound. On this basis
there is no difficulty in conceiving the rationale of the reaction
which produces the repulsion of the radiometer. I may even go further,
and affirm that it is impossible to rationally conceive radiation
producing any mechanical effects without mechanical reaction. If heat
be motion, and actual motion of actual matter, mechanical force must be
exerted to produce it, and a body which is warmer on one side than the
other, _i.e._, which is exerting more outward motion-producing force on
one side than on the other, must be subject to proportionally unequal
reaction, and, therefore, if free to move, must retreat in a direction
contrary to that of its greater activity. Regarded thus, the residual
air of the radiometer does act, not by collisions of particles between
the vane and inside of the glass vessel, but by the direct reaction
of the radiant energy which would operate irrespective of vessels,
_i.e._, upon naked radiometer vanes if carried halfway to the moon, or
otherwise freed from excess of atmospheric embarrassment.
The recent experiments of Mr. Crookes, showing retardation of the
radiometer with extreme exhaustion, seem to indicate that heat-rays,
like the electric discharge, demand a certain amount of atmospheric
matter as their carrier.
I cannot conclude these hasty and imperfect notes, written merely with
suggestive intent, without quoting a passage from the preface to the
“Correlation of Physical Forces,” which, though written so long ago,
appears to me worthy of the profoundest present consideration.
“It appears to me that heat and light maybe considered as affections;
or, according to the undulatory theory, vibrations of matter itself,
and not of a distinct ethereal fluid permeating it: these vibrations
would be propagated just as sound is propagated by vibrations of wood
or as waves by water. To my mind all the consequences of the undulatory
theory flow as easily from this as from the hypothesis of a specific
ether; to suppose which, namely, to suppose a fluid _sui generis_ and
of extreme tenuity penetrating solid bodies, we must assume, first,
the existence of the fluid itself; secondly, that bodies are without
exception porous; thirdly, that these pores communicate; fourthly, that
matter is limited in expansibility. None of these difficulties apply
to the modification of this theory which I venture to propose: and no
other difficulty applies to it which does not equally apply to the
received hypothesis.”
ON THE SOCIAL BENEFITS OF PARAFFIN.
To the inhabitants of Jupiter, who have always one, two, or three
of their four moons in active and efficient radiation, or of Saturn
displaying the broad luminous oceans of his mighty rings in addition to
the minor lamps of his eight ever-changeful satellites, the relative
merits of rushlights, candles, lamps, and gaslights may be a question
of indifference; but to us, the residents of a planet which has but
one small moon that only displays her nearly full face during a few
nights of each month, the subject of artificial light is only second in
importance to those of food and artificial heat, and every step that is
made in the improvement of our supplies of this primary necessary must
have a momentous influence on the physical comfort, and also upon the
intellectual and moral progress, of this world’s human inhabitants.
If a cockney Rip Van Winkle were to revisit his old haunts, the changes
produced by the introduction of gas would probably surprise him the
most of all he would see. He would be astonished to find respectable
people, and even unprotected females, going alone, unarmed and without
fear, at night, up the by-streets which in his days were deemed so
dangerous, and he would soon perceive that the bright gaslights had
done more than all the laws, the magistrates, and the police, to drive
out those crimes which can only flourish in darkness. The intimate
connection between physical light and moral and intellectual light and
progress is a subject well worthy of an exhaustive treatise.
We must, however, drop the general subject and come down to our
particular paraffin lamp. In the first place, this is the cheapest
light that has ever been invented—cheaper than any kind of oil
lamp—cheaper than the cheapest and nastiest of candles, and, for
domestic purposes, cheaper than gas. For large warehouses, shops,
streets, public buildings, etc., it is not so cheap as gas should be,
but is considerably cheaper than gas actually is at the price extorted
by the despotism of commercial monopoly.
The reason why it is especially cheaper for domestic purposes is,
first, because the small consumer of gas pays a higher price than the
large consumer; and secondly, because a lamp can be placed on a table
or wherever else its light is required, and therefore a small lamp
flame will do the work of a much larger gas flame. We must remember
that the intensity of light varies inversely with the square of the
distance from the source of light; thus the amount of light received
by this page from a light at one foot distance is four times as
great as if it were two feet distant, nine times as great as at three
feet, sixteen times as great as at four feet, one hundred times as
great as at ten feet, and so on. Hence the necessity of two or three
great flames in a gas chandelier suspended from the ceiling of a
moderate-sized room.
In a sitting-room lighted thus with gas, we are obliged, in order to
read comfortably by the distant source of light, to burn so much gas
that the atmosphere of the room is seriously polluted by the products
of this extravagant combustion. A lamp at a moderate distance—say
eighteen inches or two feet, or thereabouts—will enable us to read
or work with one-tenth to one-twentieth the amount of combustion, and
therefore with so much less vitiation of the atmosphere, and, if we use
a paraffin lamp, at much less expense.
But the chief value of the paraffin lamp is felt where gas is not
obtainable—in the country mansion or villa, the farmhouse, and,
most of all, in the poor man’s cottage. We have Bible Societies for
providing cheap Bibles; we have cheap standard works, cheap magazines,
cheap newspapers, etc.; but all these are unavailable to the poor man
until he can get a good and cheap light wherewith to read them at the
only time he has for reading, viz., in the evenings, when his work
is done. One shilling’s worth of cheap literature will require two
shillings’ worth of dear candles to supply the light necessary for
reading it. Therefore, the cheapening of light has quite as much to do
with the poor man’s intellectual progress as the cheapening of books
and periodicals.
For a man to read comfortably, and his wife to do her needlework, they
must have a candle for each, if dependent on tallow dips. They may,
and do, struggle on with one such candle, but the inconvenience soon
sickens them of their occupation; the man lolls out for an idle stroll,
soon encounters a far more bright and cheerful room than the gloomy one
he has just left, and, moth-like, he is attracted by the light, and
finishes up his evening in the public-house.
We may preach, we may lecture, we may coax, wheedle, or anathematize,
but no amount of words of any kind will render a gloomy ill-lighted
cottage so attractive as the bright bar and tap-room; and human nature,
irrespective of conventional distinctions of rank and class, always
seeks cheerfulness after a day of monotonous toil. Fifty years ago the
middle classes were accustomed to spend their evenings in taverns, but
now they prefer their homes, simply because they have learned to make
their homes more comfortable and attractive.
We have not yet learned how to supply the working millions with
suburban villas, but if their small rooms can be made bright and
cheerful during the long evenings, a most important step is made
towards that general improvement of social habits which necessarily
results from a greater love of home. We may safely venture to predict
that the paraffin lamp will have as much influence in elevating the
domestic character of the poorer classes as the street lamps have had
in purging the streets of our cities from the crimes of darkness that
once infested them.
A great deal has been said about the poisonous character of paraffin
works. I admit that they have much to answer for in reference to
trout—that the clumsy and wasteful management of certain ill-conducted
works has interfered with the sport of the anglers of one or two of
the trout streams of the United Kingdom—but all the assertions that
have been made relative to injury to human health are quite contrary to
truth.
The fact is that the manufacture of mineral oils from cannel and shale
is an unusually healthful occupation. The men certainly have dirty
faces, but are curiously exempt from those diseases which are most
fatal among the poor. I allude to typhus fever, and all that terrible
catalogue of ills usually classed under the head of zymotic diseases.
This has been strikingly illustrated in the Flintshire district.
The very sudden development of the oil trade in the neighborhood
of Leeswood caused that little village and the scattered cottages
around to be crowded to an extent that created the utmost alarm
among all who are familiar with the results of such overcrowding in
poor, ill-drained, and ill-ventilated cottages. Rooms were commonly
filled with lodgers who economized the apartments on the Box and Cox
principle, the night workers sleeping during the day, and the day
workers during the night, in the same beds. The extent to which this
overcrowding was carried in many instances is hardly credible.
Mr. R. Platt, who is surgeon to most of the collieries and oilworks of
this district, reports that Leeswood has enjoyed a singular immunity
from typhus and fever—that, during a period when it was prevalent as
a serious epidemic among the agricultural population living on the
slopes of the surrounding mountains, no single case occurred among the
oil-making population of Leeswood, though its position and overcrowding
seemed so directly to court its visitation. If space permitted I might
give further illustrations in reference to allied diseases.
There is no difficulty in accounting for this. Carbolic acid, one of
the most powerful of our disinfectants, is abundantly produced in the
oilworks, and this is carried by the clothes of the men, and with the
fumes of the oil, into the dwellings of the workmen and through all the
atmosphere of the neighborhood, and has thereby counteracted some of
the most deadly agencies of organic poisons. Besides this, the paraffin
oil itself is a good disinfectant.
Even the mischief done to the trout is more than counterbalanced by the
destruction of those mysterious fungoid growths which result from the
admixture of sewage matter with the water of our rivers, and are so
destructive to human health and life. The carbolic acid and paraffin
oil, in destroying these as well as the trout, are really acting as
great purifiers of the river, so that, after all, the only interest
that has suffered is the sporting interest. This same interest has
otherwise suffered. The old haunts of the snipe and woodcock, of
partridges, hares, and pheasants, are being ruthlessly and barbarously
destroyed, and—horrible to relate—hundreds of cottages, inhabited by
vulgar, hard-handed, thick-booted human beings, are taking their place.
Churches are being extended, school-houses and chapels built; penny
readings, lectures, concerts, etc., are in active operation, and even
drinking fountains are in course of construction; but the trout have
suffered and the woodcocks are gone.
We may thus measure the good against the evil as it stands here in the
headquarters of oil-making, and should add to one side the advantages
which the cheap and brilliant light affords—advantages which we might
continue to enumerate, but they are so obvious that it is unnecessary
to go further.
There is one important and curious matter which must not be omitted.
This, like the moral and intellectual advantages of the cheap paraffin
light, has hitherto remained unnoticed, viz., that the introduction
of mineral oils and solid paraffin for purposes of illumination and
lubrication has largely increased the world’s supply of food.
This may not be generally obvious at first sight; but to him, who, like
the writer, has had many a supper at an Italian osteria with peasants
and carbonari, it is obvious enough. He will remember how often he
has seen the lamp that has lighted himself and companions to their
supper filled from the same flask as supplied the salad which formed
so important a part of the supper itself. Throughout the South of
Europe salads are most important elements of national food, and when
thus abundantly eaten the oil is quite necessary, the oil is also used
for many of the cookery operations where butter is used here, and this
same olive oil has hitherto been the chief, and in some places the
sole, illuminating agent. The poor peasant of the South looks jealously
at his lamp, and feeds its stingily, for it consumes his richest and
choicest food, and, if well supplied, would eat as much as a fair-sized
baby.
The Russian peasant and other Northern people have a similar struggle
in the matter of tallow. It is their choicest dainty, and yet, to
their bitter grief, they have been compelled to burn it. Hundreds and
thousands of tons of this and of olive oil have been annually consumed
for the lubrication of our steam engines and other machines. A better
time is approaching now that paraffin lamps are so rapidly becoming
the chief illuminators of the whole civilized world, superseding the
crude tallow candle and the antique olive-oil lamp, while, at the same
time, the tallow candle is gradually being replaced by the beautiful
sperm-like paraffin candle; and, in addition to this, the greedy
engines that have consumed so much of the olive oil and the tallow are
learning to be satisfied with lubricators made from minerals kindred to
themselves.
The peasants of the sunny South will feed upon salads made doubly
unctuous and nutritious by the abundant oil; their fried meats, their
pastry, omelettes, and sauces will be so much richer and better than
heretofore, and the Russian will enjoy more freely his well-beloved and
necessary tallow, when the candle is made and the engine lubricated
with the fat extracted from coals and stones which no human stomach can
envy. I might travel on to China and tell of the work that paraffin and
paraffin oils have yet to do among the many millions there and in other
countries of the East. The great wave of mineral light has not yet
fairly broken upon their shores; but when it has once burst through the
outer barriers, it will, without doubt, advance with great rapidity,
and with an influence whose beneficence can scarcely be exaggerated.
(The above was written in the early days of paraffin lamps, and while
the writer was engaged in the distillation of paraffin oils, etc., from
the Leeswood cannel. These are now practically superseded by American
petroleum of similar composition, but distilled in Nature’s oilworks.
The anticipations that appeared Utopian at the time of writing have
since been fully realized, or even exceeded, as the wholesale price of
mineral oil has fallen from two shillings per gallon to an average of
about eightpence, and lamps have been greatly improved. At this price
the cost of maintaining a light of given power in an ordinary lamp is
about equal to that of ordinary London gas, if it were supplied at
one shilling per thousand cubic feet. The mineral oil, being a fine
hydrocarbon, does far less mischief than gas by its combustion, as may
be proved by warming a conservatory with a paraffin stove and another
with a stove. In the latter all the delicate plants will be killed; in
the first they scarcely suffer at all. If these facts were generally
understood we should be in a better position for battle with the gas
monopolies. The importation of petroleum to the United Kingdom during
the first five months of 1882 amounted to 26,297,346 gallons.)
THE SOLIDITY OF THE EARTH.
In his opening address to the Mathematical and Physical Section of the
British Association, Sir William Thomson affirmed, “with almost perfect
certainty, that, whatever may be the relative densities of rock, solid
and melted, or at about the temperature of liquefaction, it is, I
think, quite certain that cold solid rock is denser than hot melted
rock; and no possible degree of rigidity in the crust could prevent
it from breaking in pieces and sinking wholly below the liquid lava,”
and that “this process must go on until the sunk portions of the crust
build up from the bottom a sufficiently close-ribbed skeleton or frame,
to allow fresh incrustations to remain bridged across the now small
areas of lava-pools or lakes.”[11]
This would doubtless be the case if the material of the earth were
chemically homogeneous or of equal specific gravity throughout, and if
it were chemically inert in reference to its superficial or atmospheric
surroundings. But such is not the case. All we know of the earth shows
that it is composed of materials of varying specific gravities, and
that the range of this variation exceeds that which is due to the
difference between the theoretical internal heat of the earth and its
actual surface temperature.
We know by direct experiment that these materials, when fused together,
arrange themselves according to their specific gravities, with the
slight modification due to their mutual diffusibilities. If we take a
mixture of the solid elements of which the earth, so far as we know it,
is composed, fused them, and leave them exposed to atmospheric action,
what will occur?
The heavy metals will sink, the heaviest to the bottom, the lighter
metals (_i.e._, those that we call the metals of the earths, because
they form the basis of the earth’s superficial crust) will rise along
with the silicon, etc., to the surface; these and the silicon will
oxidize and combine, forming silicates, and with a sufficient supply
of carbonic acid, some of them, such as calcium, magnesium, etc.,
will form carbonates when the temperature sinks below that of the
dissociation of such compounds.
The scoria thus formed will float upon the heavy metals below and
protect them from cooling by resisting their radiation; but if in
the course of contraction of this crust some fissures are formed
reaching to the melted metals below, the pressure of the floating
solid will inject the fluid metal upwards into these fissures to a
height corresponding to the flotation depth of the solid, and thus
form metallic veins permeating the lower strata of the crust. I need
scarcely add that this would rudely but fairly represent what we know
of the earth.
But it may be objected that I only describe an imaginary experiment.
This is true as regards the whole of the materials united in a single
fusion. Nobody has yet produced a complete model with platinum and gold
in the centre, and all the other metals arranged in theoretical order
with the oxidized, silicated, and carbonated crust outside; but with a
limited number of elements this has been done, is being done daily, on
a scale of sufficient magnitude to amply refute Sir William Thomson’s
description of a fused earth solidifying from the centre outwards.
This refutation is to be seen in our blast furnaces, refining furnaces,
puddling furnaces, Bessemer ladles, steel melting-pots, cupels, foundry
crucibles; in fact, in almost every metallurgical operation down to the
simple fusion of lead or solder in a plumber’s ladle, with its familiar
floating crust of dross or oxide.
As an example I will, on account of its simplicity, take the open
hearth finery and the refining of pig-iron. Here a metallic mixture of
iron, silicon, carbon, sulphur, etc., is simply fused and exposed to
the superficial action of atmospheric air. What is the result?
Oxidation of the more oxidizable constituents takes place, and
these oxides at once arrange themselves according to their specific
gravities. The oxidized carbon forms atmospheric matter and rises above
all as carbonic acid, then the oxidized silicon, being lighter than
the iron, floats above that, and combines with aluminium or calcium
that may have been in the pig and with some of the iron; thus forming
a silicious crust closely resembling the predominating material of the
earth’s crust.
When the oxidation in the finery is carried far enough, the melted
material is tapped out into a rectangular basin or mould, usually
about 10 feet long and about 3 feet wide, where it settles and cools.
During this cooling the silica and silicates—_i.e._, the rock
matter—separate from the metallic matter and solidify on the surface
as a thin crust, which behaves in a very interesting and instructive
manner. At first a mere skin is formed. This gradually thickens, and
as it thickens and cools becomes corrugated into mountain chains and
valleys much higher and deeper, in proportion to the whole mass, than
the mountain chains and valleys of our planet. After this crust has
thickened to a certain extent volcanic action commences. Rifts, dykes,
and faults are formed by the shrinkage of the metal below, and streams
of lava are ejected. Here and there these lava streams accumulate
around their vent and form insulated conical volcanic mountains with
decided craters, from which the eruption continues for some time. These
volcanoes are relatively far higher than Chimborazo. The magnitude of
these actions varies with the quality of the pig-iron.
The open hearth finery is now but little used, but probably some are
to be seen at work occasionally in the neighborhood of Glasgow, and I
am sure that Sir William Thomson will find a visit to one of them very
interesting. Failing this, he may easily make an experiment by tapping
into a good-sized “cinder bogie” some melted pig-iron from a pudding
furnace (taking it just before the iron “comes to nature”), and leaving
the melted mixture to cool slowly and undisturbed.
The cinder of the blast furnace, which in like manner floats on the top
of the melted pig-iron, resembles still more closely the prevailing
rock-matter of the earth, on account of the larger proportion, and the
varied compounds, of earth-metals it contains.
For the volcanic phenomena alone he need simply watch what occurs
when in the ordinary course of puddling the cinder is run into a
large bogie, and the bogie is left to cool standing upright. I need
scarcely add that these phenomena strikingly illustrate and confirm Mr.
Mallett’s theory of earthquakes, volcanoes, and mountain-formation.
In merely passing through an iron-making district one may see the
results of what I have called the volcanic action, by simply observing
the form of those oyster-shaped or cubical blocks of cinder that are
heaped in the vicinity of every blast furnace that has been at work for
some time. Radial ridges or consolidated miniature lava-streams are
visible on the exposed face of nearly, if not quite all of these. They
were ejected or squeezed up from below while the mass was cooling, when
the outer crust had consolidated but the inner portion still remained
liquid. Many of these are large enough, and sufficiently well-marked,
to be visible from a railway carriage passing a cinder heap near the
road.[12]
A CONTRIBUTION TO THE HISTORY OF ELECTRIC LIGHTING.
As the subject of lighting by electricity is occupying so much public
attention, and the merits of various inventors and inventions are so
keenly discussed, the following facts may have some historical interest
in connection with it.
In October, 1845, I was consulted by some American gentlemen concerning
the construction of a large voltaic battery for experimenting upon an
invention, afterwards described and published in the specification of
“King’s Patent Electric Light” (Letters Patent granted for Scotland,
November 26, 1845; enrolled March 25, 1846; English Patent sealed
November 4, 1845).
Mr. King was not the inventor, but he and Mr. Dorr supplied capital,
and Mr. Snyder also held a share, which was afterwards transferred to
myself. The inventor was Mr. Starr, a young man about twenty-five years
of age, and one of the ablest experimental investigators with whom I
have ever had the privilege of near acquaintance.
He had been working for some years on the subject, commencing with the
ordinary arc between charcoal points. His first efforts were directed
to maintaining constancy, and he showed me, in January of 1846, an
arrangement by which he succeeded in effecting an automatic renewal of
contact by means of an electro-magnet, the armature of which received
the electric flow, when the arc was broken, and which thus magnetized
brought the carbons together and then allowed them to be withdrawn to
their required separation, when the flow returned. This device was
almost identical with that subsequently re-invented and patented by Mr.
Staite (quite independently, I believe), and which, with modifications,
has since been rather extensively used.
Although successful so far, he was not satisfied. He reasoned out the
subject, and concluded that the electric spark between metals, the
electric arc between the carbons, and other luminous electric phenomena
are secondary effects due to the heating and illumination of electric
carriers; that the electric spark of the conductors of ordinary
electrical machines is simply a transfer of incandescent particles
of metal, which effect a kind of electric convection, known as the
disruptive discharge; and that the more brilliant arc between the
carbon points is simply due to the use of a substance which breaks up
more readily, and gives a longer, broader, and more continuous stream
of incandescent convection particles.
This is now readily accepted, but at that time was only dawning upon
the understanding of electricians. I am satisfied that Mr. Starr worked
out the principle quite originally. He therefore concluded that, the
light being due to solid particles heated by electric disturbance,
it would be more advantageous—as regards steadiness, economy, and
simplicity—to place in the current a continuous solid barrier, which
should present sufficient resistance to its passage to become bodily
incandescent without disruption.
This was the essence of the invention specified in King’s Patent as “a
communication from abroad,” which claims the use of continuous metallic
and carbon conductors, intensely heated by the passage of a current of
electricity, for the purposes of illumination.
The metal selected was platinum, which, as the specification states,
“though not so infusible as iridium, has but little affinity for
oxygen, and offers a great resistance to the passage of the current.”
The form of thin sheets known by the name of leaf-platinum is described
as preferable. These to be rolled between sheets of copper in order to
secure uniformity, and to be carefully cut in strips of equal width,
and with a clean edge, in order that one part may not be fused before
the other parts have obtained a sufficiently high temperature to
produce a brilliant light. This strip to be suspended between forceps.
I need not describe the arrangement for regulating the distance
between the forceps, for directing the current, etc., as we soon
learned that this part of the invention was of no practical value,
on account of the narrow margin between efficient incandescence and
the fusion of the platinum. The experiments with the large battery
that I made—consisting of 100 Daniell cells, with two square feet of
working surface of each element in each cell, and the copper-plates
about three-quarters of an inch distant from the zinc—satisfied all
concerned that neither platinum nor any available alloy of platinum
and iridium could be relied upon; especially when the grand idea of
subdividing the light by interposing several platinum strips in the
same circuit, and working with a proportionally high power, was carried
out.
This drove Mr. Starr to rely upon the second part of the specification,
viz., that of using a small stick of carbon made incandescent in a
Torricellian vacuum. He commenced with plumbago, and, after trying many
other forms of carbon, found that which lines gas-retorts that have
been long in use to be the best.
The carbon stick of square section, about one tenth of an inch thick
and half an inch working length, was held vertically, by metallic
forceps at each end, in a barometer tube, the upper part of which,
containing the carbon, was enlarged to a sort of oblong bulb. A thick
platinum wire from the upper forceps was sealed into the top of the
tube and projected beyond; a similar wire passed downwards from the
lower forceps, and dipped into the mercury of the tube, which was so
long that when arranged as a barometer the enlarged end containing the
carbon was vacuous.
Considerable difficulty was at first encountered in supporting this
fragile stick. Metallic supports were not available, on account of
their expansion; and, finally, little cylinders of porcelain were used,
one on each side of the carbon stick, and about three eighths of an
inch distant.
By connecting the mercury cup with one terminal of the battery, and the
upper platinum-wire with the other, a brilliant and perfectly steady
light was produced, not so intense as the ordinary disruption arc
between carbons, but equally if not more effective, on account of the
magnitude of brilliant radiating surface.
Some curious phenomena accompanied this illumination of the carbon. The
mercury column fell to about half its barometric height, and presently
the glass opposite the carbon stick became slightly dimmed by the
deposition of a thin film of sooty deposit.
At first the depression of the mercury was attributed to the formation
of mercurial vapor, and is described accordingly in the specification;
but further observation refuted this theory, for no return of the
mercury took place when the tube was cooled. The depression was
permanent. The formation of vaporous carbon was suggested by one of the
capitalists; but neither Mr. Starr nor myself was satisfied with this,
nor with any other surmise we were able to make during Mr. Starr’s
lifetime, nor up to the period of final abandonment of the enterprise.
When this occurred the remaining apparatus was assigned to me, and I
retained possession of the finally arranged tube and carbon for many
years, and have shown it in action worked by a small Grove’s battery
in the Town Hall of Birmingham, and many times to my pupils at the
Birmingham and Midland Institute.
These exhibitions suggested an explanation of the mysterious gaseous
matter, which I believe to be the correct one, and also of the carbon
deposit. It is this:—That the carbon contains occluded oxygen; that
when the carbon is heated some of this oxygen combines with the
carbon, forming carbonic oxide and carbonic acid, and a little smoke.
I proved the presence of carbonic acid by the usual tests, but did not
quantitatively determine its proportion of the total atmosphere.
If I were fitting up another tube on this principle I should wash it
with a strong solution of caustic potash before filling with mercury,
and allow some of the potash solution to float on the mercury surface,
by filling the tube while the glass remained moistened with the
solution. My object would be to get rid of the carbonic acid as soon as
formed, as the observations I have made lead me to believe that—when
the carbon stick is incandescent in an atmosphere of carbonic acid or
carbonic oxide—a certain degree of dissociation and re-combination is
continually occurring, which weakens and would ultimately break up the
carbon stick, and increases the sooty deposit.
The large battery was arranged for intensity, but even then it was
found that the quantity (I use the old-fashioned terms) of electricity
was excessive, and that it worked more advantageously when the cells
were but partially filled with acid and sulphate. A larger stick of
carbon might have been used with the whole surface in full action.
After working the battery in various ways, and duly considering the
merits of the other forms of battery then in use, Mr. Starr was driven
to the conclusion that for the purposes of practical illumination
the voltaic battery is a hopeless source of power, and that
magneto-electric machinery driven by steam-power must be used. I fully
concurred with him in this conclusion, so did Mr. King, Mr. Dorr, and
all concerned.
Mr. Starr then set to work to devise a suitable dynamo-electric
machine, and, following his usual course of starting from first
principles, concluded that all the armatures hitherto constructed
were defective in one fundamental element of their arrangement. The
thick copper wire surrounding the soft iron core necessarily follows
a spiral course, like that of a coarse screw-thread; but the electric
current or lines of force, which it is designed to pick up and carry,
circulate at right angles to the axis of the core, and extend to some
distance beyond its surface. The problem thus presented is to wind
around the soft iron a conductor that shall be broad enough to grasp
a large proportion of this outspread force, and yet shall follow its
course as nearly as possible by standing out at right angles to the
axis of the armature. This he endeavored to effect by using a core of
square section, and winding round it a broad ribbon of sheet copper,
insulated on both sides by cementing on its surfaces a layer of silk
ribbon. This armature was laid with one edge against one side of the
core, and carried on thus to the angle; then turned over so that its
opposite edge should be presented to the next side of the core; this
side to be followed in like manner, the ribbon similarly turned again
at the next corner, and so on till the core became fully enclosed or
armed with the continuous ribbon, which thus encircled the core with
its edges outwards, and nearly at right angles to the axis, in spite of
its width, which might be increased to any extent found by experiment
to be desirable.
At this stage my direct co-operation and confidential communication
with Mr. Starr ceased, as I remained in London while he went to
Birmingham in order to get his machinery constructed, and to apply it
at the works of Messrs. Elkington, who had then recently introduced the
principle of dynamo-electric motive-power for electro-plating, etc.,
and were, I believe, using Woolrich’s apparatus, the patent for which
was dated August 1, 1842, and enrolled February 1, 1843.
I am unable to state the results of his efforts in Birmingham. I
only heard the murmurs of the capitalists, who loudly complained of
expenditure without results. They had dreamed the same dream that Mr.
Edison has recently re-dreamed, and has told the world so loudly.
They supposed that the mechanically excited current might be carried
along great lengths of wire, and the carbons interposed wherever
required, and that the same electricity would flow on and do the
duty of illumination over and over again as a river may fall over a
succession of weirs and turn water-wheels at each. Mr. Starr knew
better; his scepticism was misinterpreted; he was taunted with failure
and non-fulfilment of the anticipations he had raised, and with the
fruitless expenditure of large sums of other people’s money. He was
a high-minded, honorable, and very sensitive man, suffering already
from overworked brain before he went to Birmingham. There he worked
again still harder, with further vexation and disappointment, until
one morning he was found dead in his bed. Having, during my short
acquaintance with him, enjoyed his full confidence in reference to all
his investigations, I have no hesitation in affirming that his early
death cut short the career of one who otherwise would have largely
contributed to the progress of experimental science, and have done
honor to his country.
His martyrdom, for such it was, taught me a useful lesson I then much
needed, viz., to abstain from entering upon a costly series of physical
investigations without being well assured of the means of completing
them, and, above all, of being able to afford to fail.
There are many others who sorely need to be impressed with the same
lesson, especially at this moment and in connection with this subject.
The warning is the most applicable to those who are now misled by a
plausible but false analogy. They look at the progress made in other
things, the mighty achievements of modern Science, and therefore infer
that the electric light—even though unsuccessful hitherto—may be
improved up to practical success, as other things have been. A great
fallacy is hidden here. As a matter of fact the progress made in
electric lighting since Mr. Starr’s death, in 1846, has been very small
indeed. As regards the lamp itself no progress whatever has been made.
I am satisfied that Starr’s continuous carbon stick, properly managed
in a true vacuum, or an atmosphere free from oxygen, carbonic oxide,
carbonic acid, or other oxygen compound, is the best that has yet been
placed before the public for all purposes where exceptionally intense
illumination (as in lighthouses) is not demanded.[13]
Comparing electric with gas-lighting, the hopeful believers in
progressive improvement appear to forget that gas-making and
gas-lighting are as susceptible of further improvement as electric
lighting, and that, as a matter of fact, its practical progress
during the last forty years is incomparably greater than that of
the electric light. I refer more particularly to the practical and
crucial question of economy. The bi-products, the ammoniacal salts,
the liquid hydrocarbons, and their derivatives, have been developed
into so many useful forms by the achievements of modern chemistry,
that these, with the coke, are of sufficient value to cover the whole
cost of manufacture, and leave the gas itself as a volatile residuum
that costs nothing. It would actually and practically cost nothing,
and might be profitably delivered to the burners of gas consumers (of
far better quality than now supplied in London) at one shilling per
thousand cubic feet, if gas-making were conducted on sound commercial
principles,—that is, if it were not a corporate monopoly, and were
subject to the wholesome stimulating influence of free competition and
private enterprise. As it is, our gas and the price we pay for it are
absurdities; and all calculations respecting the comparative cost of
new methods of illumination should be based not on what we _do_ pay
per candle-power of gas-light, but what we _ought_ to pay and _should_
pay if the gas companies were subjected to desirable competition, or
visited with the national confiscation I consider they deserve.
Having had considerable practical experience in the commercial
distillation of coal for the sake of its liquid and solid
hydrocarbons, I speak thus plainly and with full confidence.
There is yet another consideration, and one of vital importance, to
be taken into account, viz., that—whether we use the electric light
derived from a dynamo-electric source, or coal-gas—our primary source
of illuminating power is coal, or rather the chemical energy derivable
from the combination of its hydrogen and carbon with oxygen. Now this
chemical energy is a limited quantity, and the progress of Science can
no more increase this quantity than it can make a ton of coal weigh 21
cwts. by increasing the quantity of its gravitating energy.
The demonstrable limit of scientific possibilities is the economical
application of this limited store of energy, by converting it into the
demanded form of force without waste. The more indirect and roundabout
the method of application, the greater must be the loss of power in
the course of its transfer and conversion. In heating the boiler that
sets the dynamo-electric machine to work, about one-half the energy
of the coal is wasted, even with the best constructed furnaces. This
merely as regards the quantity of water evaporated. In converting the
heat-force into mechanical power—raising the piston, etc., of the
steam-engine—this working half is again seriously reduced. In further
converting this residuum of mechanical power into electrical energy,
another and considerable loss is suffered in originating and sustaining
the motion of the dynamo-electric machine, in the dissipation of the
electric energy that the armature cannot pick up, and in overcoming the
electrical resistances to its transfer.
I am unable to state the amount of this loss in trustworthy figures,
but should be very much surprised to learn that, with the best
arrangements now known, more than one-tenth of the original energy
of the coal is made practically available. This small illuminating
residuum may, and doubtless will, be increased by the progress of
practical improvement; but from the necessary nature of the problem,
the power available for illumination at the end of the series must
always be but a small portion of that employed at the beginning.
In burning the gas derived from coal we obtain its illuminating power
_directly_, and if we burn it properly we obtain nearly all. The coke
residuum is also directly used as a source of heat. The chief waste of
the original energy in the gas-works is represented by that portion
of the coke that is burned under the retorts, and in obtaining the
relatively small amount of steam-power demanded in the works. These are
far more than paid for by the value of the liquid hydrocarbons and the
ammonia salts, when they are properly utilized.
In concluding my narrative, I may add that after Mr. Starr’s death
the patentees offered to engage me on certain terms to carry on his
work. I declined this, simply because I had seen enough to convince
me of the impossibility of any success at all corresponding to their
anticipations. During the intervening thirty years I have abstained
from further meddling with the electric light, because all that I had
seen then, and have heard of since, has convinced me that—although as
a scientific achievement the electric light is a splendid success—its
practical application to all purposes where cost is a matter of serious
consideration is hopeless, and must of necessity continue to be so.
Whoever can afford to pay some shillings per hour for a single splendid
light of solar completeness can have it without difficulty, but not so
where the cost in pence per hour per burner has to be counted.
I should add that before the publication of King’s specification,
Mr. (now Sir William) Grove proposed the use of a helix or coil of
platinum, made incandescent by electricity, as a light to be used for
certain purposes. This was shown at the Royal Society on or about
December 1, 1845.
Since the publication of the above in 1879, I have learned, from a
paper in the “Quarterly Journal of Science,” by Professor Ayrton,
that in 1841 an English patent was granted to De Moylens for electric
lighting by incandescence.
THE FORMATION OF COAL.
In the course of a pedestrian excursion made in the summer of 1855
I came upon the Aachensee, one of the lakes of North Tyrol, rarely
visited by tourists. It is situated about 30 miles N.E. of Innispruck,
and fills the basin of a deep valley, the upper slopes of which
are steep and richly wooded. The water of this lake is remarkably
transparent and colorless. With one exception, that of the Fountain of
Cyane—a deep pool forming the source of the little Syracusan river—it
is the most transparent body of water I remember to have seen. This
transparency revealed a very remarkable sub-aqueous landscape. The
bottom of the lake is strewn with branches and trunks of trees, which
in some parts are in almost forest-like profusion. As I was alone in
a rather solitary region, and carrying only a satchel of luggage, my
only means of further exploration were those afforded by swimming and
diving. Being an expert in these, and the July summer day very calm
and hot, I remained a long time in the water, and, by swimming very
carefully to avoid ripples, was able to survey a considerable area of
the interesting scene below.
The fact which struck me the most forcibly, and at first appeared
surprising, was the upright position of many of the large trunks,
which are of various lengths—some altogether stripped of branches,
others with only a few of the larger branches remaining. The roots of
all these are more or less buried, and they present the appearance of
having grown where they stand. Other trunks were leaning at various
angles and partly buried, some trunks and many branches lying down.
On diving I found the bottom to consist of a loamy powder of gray
color, speckled with black particles of vegetable matter—thin scaly
fragments of bark and leaves. I brought up several twigs and small
branches, and with considerable difficulty, after a succession of
immersions, succeeded in raising a branch about as thick as my arm and
about eight feet long, above three-fourths of which was buried, and
only the end above ground in the water. My object was to examine the
condition of the buried and immersed wood, and I selected this as the
oldest piece I could reach.
I found the wood very dark, the bark entirely gone, and the annual
layers curiously loosened and separable from each other, like
successive rings of bark. This continued till I had stripped the stick
to about half of its original thickness, when it became too compact to
yield to further stripping.
This structure apparently results from the easy decomposition of the
remains of the original cambium of each year, and may explain the
curious fact that so many specimens of fossilized wood exhibit the
original structure of the stem, although all the vegetable matter has
been displaced by mineral substances. If this stem had been immersed
in water capable of precipitating or depositing mineral matter in very
small interstices, the deposit would have filled up the vacant spaces
between these rings of wood as the slow decomposition of the vegetable
matter proceeded. At a later period, as the more compact wood became
decomposed, it would be substituted by a further deposit, and thus
concentric strata would be formed, presenting a mimic counterpart of
the vegetable structure.
The stick examined appeared to be a branch of oak, and was so fully
saturated with water that it sank rapidly upon being released.
On looking around the origin of this sub-aqueous forest was obvious
enough. Here and there the steep wooded slopes above the lake were
broken by long alleys or downward strips of denuded ground, where storm
torrents, or some such agency, had cleared away the trees and swept
most of them into the lake. A few uprooted trees lying at the sides of
these bare alleys told the story plainly enough. Most of these had a
considerable quantity of earth and stones adhering to their roots: this
explains the upright position of the trees in the lake.
Such trees falling into water of sufficient depth to enable them to
turn over must sink root downwards, or float in an upright position,
according to the quantity of adhering soil. The difference of depth
would tend to a more rapid penetration of water in the lower parts,
where the pressure would be greatest, and thus the upright or oblique
position of many of the floating trunks would be maintained till they
absorbed sufficient water to sink altogether.
It is generally assumed that fossil trees which are found in an upright
position have grown on the spot where they are found. The facts I have
stated show that this inference is by no means necessary, not even when
the roots are attached and some soil is found among them. In order to
account for the other surroundings of these fossil trees a very violent
hypothesis is commonly made, viz., that the soil on which they grew
sank down some hundreds of feet without disturbing them. This demands a
great strain upon the scientific imagination, even in reference to the
few cases where the trees stand perpendicular. As the majority slope
considerably the difficulty is still greater. I shall presently show
how trees like those immersed in Aachensee may have become, and are now
becoming, imbedded in rocks similar to those of the Coal Measures.
In the course of subsequent excursions on the fjords of Norway I was
reminded of the sub-aqueous forest of the Aachensee, and of the paper
which I read at the British Association meeting of 1865, of which
the above is an abstract—not by again seeing such a deposit under
water, for none of the fjords approach the singular transparency of
the lake, but by a repetition on a far larger scale of the downward
strips of denuded forest ground. Here, in Norway, their magnitude
justifies me in describing them as vegetable avalanches. They may be
seen on the Sognefjord, and especially on those terminal branches of
this great estuary, of which the steep slopes are well wooded. But
the most remarkable display that I have seen was in the course of the
magnificent, and now easily made, journey up the Storfjord and its
extension and branches, the Slyngsfjord, Sunelvsfjord, Nordalsfjord,
and Geirangerfjord. Here these avalanches of trees, with their
accompaniment of fragments of rock, are of such frequent occurrence
that sites of the farm-houses are commonly selected with reference
to possible shelter from their ravages. In spite of this they do not
always escape. In the October previous to my last visit a boat-house
and boat were swept away; and one of the most recent among the tracks
that I saw reached within twenty yards of some farm-buildings.
What has become of the millions of trees that are thus falling, and
have fallen, into the Norwegian fjords during the whole of the present
geological era? In considering this question we must remember that the
mountain slopes forming the banks of these fjords continue downwards
under the waters of the fjords which reach to depths that in some parts
are to be counted in thousands of feet.
It is evident that the loose stony and earthy matter that accompanies
the trees will speedily sink to the bottom and rest at the foot of
the slope somewhat like an ordinary sub-aerial talus, but not so the
trees. The impetus of their fall must launch them afloat and impel them
towards the middle of the estuary, where they will be spread about
and continue floating, until by saturation they become dense enough
to sink. They will thus be pretty evenly distributed over the bottom.
At the middle part of the estuary they will form an almost purely
vegetable deposit, mingled only with the very small portion of mineral
matter that is held in suspension in the apparently clear water. This
mineral matter must be distributed among the vegetable matter in the
form of impalpable particles having a chemical composition similar to
that of the rocks around. Near the shores a compound deposit must be
formed consisting of trees and fragments of leaves, twigs, and other
vegetable matter mixed with larger proportions of the mineral _débris_.
If we look a little further at what is taking place in the fjords
of Norway we shall see how this vegetable deposit will ultimately
become succeeded by an overlying mineral deposit which must ultimately
constitute a stratified rock.
All these fjords branch up into inland valleys down which pours a
brawling torrent or a river of some magnitude. These are more or less
turbid with glacier mud or other detritus, and great deposits of this
material have already accumulated in such quantity as to constitute
characteristic modern geological formations bearing the specific Norsk
name of _ören_, as _Laerdalsören_, _Sundalsören_, etc., describing
the small delta plains at the mouth of a river where it enters the
termination of the fjord, and which, from their exceptional fertility,
constitute small agricultural settlements bearing these names, which
signify the river sands of _Laerdal_, _Sundal_, etc. These deposits
stretch out into the fjord, forming extensive shallows that are
steadily growing and advancing further and further into the fjord.
One of the most remarkable examples of such deposits is that brought
by the Storelv (or Justedals Elv), which flows down the Justedal,
receiving the outpour from its glaciers, and terminates at Marifjören.
When bathing here I found an extensive sub-aqueous plain stretching
fairly across that branch of the Lyster fjord into which the Storelv
flows. The waters of the fjord are whitened to a distance of two or
three miles beyond the mouth of the river. These deposits must, if
the present conditions last long enough, finally extend to the body,
and even to the mouth, of the fjords, and thus cover the whole of the
bottom vegetable bed with a stratified rock in which will be entombed,
and well preserved, isolated specimens of the trees and other vegetable
forms corresponding to those accumulated in a thick bed below, but
which have been lying so long in the clear waters that they have become
soddened into homogeneous vegetable pulp or mud, only requiring the
pressure of solid superstratum to convert them into coal.
The specimens of trees in the upper rock, I need scarcely add, would be
derived from the same drifting as that which produced the lower pulp;
but these coming into the water at the period of its turbidity and of
the rapid deposition of mineral matter, would be sealed up one by one
as the mineral particles surrounding it subsided. Fossils of estuarine
animals would, of course, accompany these, or of fresh-water animals
where, instead of a fjord, the scene of these proceedings is an inland
lake. In reference to this I may state that at the inner extremities of
the larger Norwegian fjords the salinity of the water is so slight that
it is imperceptible to taste. I have freely quenched my thirst with the
water of the Sörfjord, the great inner branch of the Hardanger, where
pallid specimens of bladder wrack were growing on its banks.
In the foregoing matter-of-fact picture of what is proceeding on a
small scale in the Aachensee, and on a larger in Norway, we have, I
think, a natural history of the formation, not only of coal seams, but
also of the Coal Measures around and above them.
The theory which attributed our coal seams to such vegetable
accumulations as the rafts of the Mississippi is now generally
abandoned. It fails to account for the state of preservation and the
position of many of the vegetable remains associated with coal.
There is another serious objection to this theory that I have not
seen expressed. It is this: rivers bringing down to their mouths
such vegetable deltas as are supposed, would also bring considerable
quantities of earthy matter in suspension, and this would be deposited
with the trees. Instead of the 2 or 3 per cent of incombustible ash
commonly found in coal, we should thus have a quantity more nearly like
that found in bituminous shales which may thus be formed, viz., from 20
to 80 per cent.
The alternative hypothesis now more commonly accepted—that the
vegetation of our coal-fields actually grew where we find it—is also
refuted by the composition of coal-ash. If the coal consisted simply
of the vegetable matter of buried forests its composition should
correspond to that of the ashes of plants; and the refuse from our
furnaces and fireplaces would be a most valuable manure. This we know
is not the case. Ordinary coal-ash, as Bischof has shown, nearly
corresponds to that of the rocks with which it is associated; and he
says that “the conversion of vegetable substances into coal has been
effected by the agency of water;” and also that coal has been formed,
not from dwarfish mosses, sedges, and other plants which now contribute
to the growth of our peat-bogs, but from the stems and trunks of
the forest trees of the Carboniferous Period, such as _Sigillariæ_,
_Lepdodendra_, and _Coniferæ_.[14] All we know of these plants teaches
us that they could not grow in a merely vegetable soil containing but
2 or 3 per cent of mineral matter. Such must have been their soil for
hundreds of generations in order to give a depth sufficient for the
formation of the South Staffordshire ten-yard seam.
All these and other difficulties that have stood so long in the way
of a satisfactory explanation of the origin of coal appear to me to
be removed if we suppose that during the Carboniferous Period Britain
and other coal-bearing countries had a configuration similar to that
which now exists in Norway, viz., inland valleys terminating in marine
estuaries, together with inland lake basins. If to this we superadd the
warm and humid climate usually attributed to the Carboniferous Period,
on the testimony of its vegetable fossils, all the conditions requisite
for producing the characteristic deposits of the Coal Measures are
fulfilled.
We have first the under-clay due to the beginning of this state of
things, during which the hill slopes were slowly acquiring the first
germs of subsequent forest life, and were nursing them in their scanty
youth. This deposit would be a mineral mud with a few fossils and
that fragmentary or fine deposit of vegetable matter that darkens the
carboniferous shales and strips the sandstones. Such a bed of dark
consolidated mud, or fine clay, is found under every seam of coal, and
constitutes the “floor” of the coal pit. The characteristic striped
rocks—the “linstey” or “linsey” of the Welsh colliers—is just such as
I found in the course of formation in the Aachensee near the shore, as
described above.
The prevalence of estuarine and lacustrine fossils in the Coal Measures
is also in accordance with this: the constitution of coal-ash is
perfectly so. Its extreme softness and fineness of structure; its
chemical resemblance to the rocks around, and above, and below; and
oblong basin form common to our coal seams; the apparent contradiction
of such total destruction of vegetable structure common to the true
coal seams, while immediately above and below them are delicate
structures well preserved, is explained by the more rapid deposition of
the latter, and the slow soddening of the former as above described.
I do not, however, offer this as an explanation of the formation of
_every kind of coal_. On the contrary, I am satisfied that cannel coal,
and the black shales usually associated with it, have a different
origin from that of the ordinary varieties of bituminous coal. The
fact that the products of distillation of cannel and these shales form
different series of hydrocarbons from those of common coal, and that
they are nearly identical with those obtained by the distillation of
peat, is suggestive of origin in peat-bogs, or something analogous to
them.
To the above I may add the concluding sentences of the chapter on Coal
in Lyell’s “Elements of Geology.” Speaking of fossils in the Coal
Measures, he says: “The rarity of air-breathers is a very remarkable
fact when we reflect that our opportunities of examining strata _in
close connection with ancient land_ exceed in this case all that we
enjoy in regard to any other formations, whether primary, secondary, or
tertiary. We have ransacked hundreds of soils replete with the fossil
roots of trees, have dug out hundreds of erect trunks and stumps which
stood in the position in which they grew, have broken up myriads of
cubic feet of fuel still retaining its vegetable structure, and, after
all, we continue almost as much in the dark respecting the invertebrate
air-breathers of this epoch, _as if the coal had been thrown down
in mid-ocean_. The early date of the carboniferous strata cannot
explain the enigma, because we know that while the land supported a
luxuriant vegetation, the contemporaneous seas swarmed with life—with
Articulata, Mollusca, Radiata, and Fishes. We must, therefore, collect
more facts if we expect to solve a problem which, in the present state
of science, cannot but excite our wonder; and we must remember how
much the conditions of this problem have varied within the last twenty
years. We must be content to impute the scantiness of our data and our
present perplexity partly to our want of diligence as collectors, and
partly to our want of skill as interpreters. We must also confess that
our ignorance is great of the laws which govern the fossilization of
land animals, whether of low or high degree.”
The explanation of the origin of coal which I have given in the
foregoing meets all these difficulties. It shows how vast accumulations
of vegetable matter may have been formed “in close connection with
the ancient land,” and yet “as if the coal had been thrown down in
mid-ocean” as far as the remains of terrestrial animals are concerned.
It explains the nearly total absence of land shells, and of the remains
of other animals that must have lived in the forests producing the
coal, and which would have been buried there with the coal had it been
formed on land as usually supposed. It also meets the cases of the rare
and curious exceptions, seeing that occasionally a land animal would
here and there be drowned in such fjords under circumstances favorable
to its fossilization.
THE SOLAR ECLIPSE OF 1871.
THE FIRST TELEGRAMS.
This time we may fairly expect some approach to a solution of the
riddle of the corona, as the one essential which neither scientific
skill nor Government liberality could secure to the eclipse observers,
has been afforded, viz., fine weather. The telegraph has already
informed us of this, and also that good use has been made of the
good weather. From one station we are told: “Thin mist; spectroscope
satisfactory; reversion of lines entirely confirmed; six good
photographs.” From another: “Weather fine; telescopic and camera
photographs successful; ditto polarization; good sketches; many bright
lines in spectrum.”
This is very different from the gloomy accounts of the expedition of
last year; when we consider that the different observers are far apart,
and that if all or some of them are similarly favored we shall have in
the photographs a series of successive pictures taken at intervals of
time sufficiently distant to reveal any progressive changes that may
have occurred in the corona while the moon’s shadow was passing from
one station to the other. I anticipate some curious revelations from
these progressive photographs, that may possibly reconcile the wide
differences in the descriptions that competent observers have given of
the corona of former eclipses, which they had seen at stations distant
from each other.
Barely two years have elapsed since I suggested, in “The Fuel of the
Sun,” that the great solar prominences and the corona are due to
violent explosions of the dissociated elements of water; that the
prominences are the gaseous flashes, and the corona the ejected scoria,
or solidified metallic matter belched forth by the furious cannonade
continually in progress over the greater portion of the solar surface.
This explanation at first appeared extravagant, especially as it was
carried so far as to suggest that not merely the corona, but the
zodiacal light, the zone of meteors which occasionally drop showers of
solid matter upon the earth, and even the “pocket-planets” or asteroids
so irregularly scattered between the orbits of Mars and Jupiter,
consist of solid matter thus ejected by the great solar eruptions.
Even up to the spring of the present year, when Mr. Lockyer and other
leaders of the last year’s expeditions reported their imperfect
results, and compared them with various theories, this one was not
thought worthy of their attention.
Since that time—during the past six or eight months—a change has
taken place which strikingly illustrates the rapid progress of solar
discovery. Observations and calculations of the force and velocity of
particular solar eruptions have been made, and the results have proved
that they are amply sufficient to eject solid missiles even further
than I supposed them to be carried.
Mr. Proctor, basing his calculations upon the observations of Respighi,
Zöllner, and Professor Young, has concluded that it is even possible
that meteoric matter may be ejected far beyond the limits of our solar
system into the domain of the gravitation of other stars, and that
other stars may in like manner bombard the sun.
This appears rather startling; but, as I have already said, the
imagination of the poet and the novelist is beggared by the facts
revealed by the microscope, so I may now repeat the assertion, and
state it still more strongly, in reference to the revelations of the
telescope and the spectroscope.
As a sample of these, I take the observations of Professor Young, made
on September 7th last, and described fully in “Nature” on October 19.
He first observed a number of the usual flame-prominences having the
typical form which has been compared to a “banyan grove.” One of
these banyans was greater than the rest. This monarch of the solar
flame-forest measured _fifty-four thousand miles in height_, and its
outspreading measured in one direction about _one hundred thousand
miles_. It was a large eruption-flame, but others much larger have been
observed, and Professor Young would probably have merely noted it among
the rest, had not something further occurred. He was called away for
twenty-five minutes, and when he returned “the whole thing had been
literally blown to shreds by some inconceivable uprush from beneath.”
The space around “was filled with flying _débris_—a mass of detached
vertical fusiform filaments, each from 10 sec. to 30 sec. long by 2
sec. or 3 sec. wide, brighter and closer together where the pillars had
formerly stood, _and rapidly ascending_.” Professor Young goes on to
say, that “When I first looked, some of them had already reached a
height of 100,000 miles, and while I watched they rose, with a motion
almost perceptible to the eye, until in ten minutes the uppermost were
200,000 miles above the solar surface. This was ascertained by careful
measurement.”
Here, then, we have an observed velocity of 10,000 miles per minute,
and this is the gaseous matter, merely the flash of the gun by which
the particles of solidified solar matter are supposed to be projected.
The reader must pause and reflect, in order to form an adequate
conception of the magnitudes here treated—100,000 miles long and
54,000 miles high! What does this mean? Twelve and a half of our worlds
placed side by side to measure the length, and six and three quarters,
piled upon each other, to measure the height! A few hundred worlds as
large as ours would be required to fill up the whole cubic contents of
this flame-cloud. The spectroscope has shown that these prominences
are incandescent hydrogen. Most of my readers have probably seen a
soap-bubble or a bladder filled with the separated elements of water,
and then exploded, and have felt the ringing in their ears that has
followed the violent detonation.
Let them struggle with the conception of such a bubble or bladder
magnified to the dimensions of only one such a world as ours, and
then exploded; let them strain their power of imagination even to the
splitting point, and still they must fail most pitifully to picture
the magnitude of this solar explosion observed on September 7th last,
which flashed out to a magnitude of more than five hundred worlds,
and then expanded to the size of more than five thousand worlds, even
while Professor Young was watching it. Professor Young concludes his
description by stating that “it seems far from impossible that the
mysterious coronal streamers, if they turn out to be truly solar, as
now seems likely, may find their origin and explanation in such events.”
This, and a number of similar admissions, suggestions, and conclusions
from the leading astronomers, indicate that the eruption theory of the
corona will not be passed over in silence by the observers of this
eclipse, and it is to this that I have referred in the above remarks
respecting the interest attaching to a series of photographs showing
successive states of this outspreading enigma.
Father Secchi’s spectroscopic observations on the uneclipsed sun led
him to assert the existence of a stratum of glowing metallic vapors
immediately below the envelope connected with the hydrogen of the
eruptions. This is just what is required by my eruption theory to
supply the solid materials of the ejections forming the corona.
Professor Young’s announcement of the reversal of the spectroscopic
lines at the moment when the stratum was seen independently of the
general solar glare, startled Mr. Lockyer and others who had disputed
the accuracy of the observations of the great Italian observer, as it
confirmed them so completely. Scepticism still prevailed, and Young’s
observation was questioned; but now even our slender telegraphic
communication from Colonel Tenant to Dr. Huggins indicates that the
question must be no longer contested. “Reversion of lines entirely
confirmed” is a message so important that if the expeditions had done
no more than this, all their cost in money and scientific labor would
be amply repaid in the estimation of those who understand the value of
pure truth.
A few more fragments of intelligence respecting the Eclipse Expedition
have reached us, the last Indian mail having started just after
the eclipse occurred. They fully confirm the first telegraphic
announcement, rather strengthening than otherwise the expectations of
important results, especially in reference to the photographs of the
corona.
I have read in the Ceylon newspapers some full descriptions by amateur
observers, in which the general magnificence of the phenomena is
described. From these it is evident that the corona must have been
displayed in its full grandeur; but as the writers do not attempt to
describe those features which have at the present moment a special
scientific interest, I shall not dwell upon them, but await the
publication of the official report of the chief, and of the more
important collateral observing expeditions.
The unsophisticated reader may say “Are not one man’s eyes as good as
another’s, and why should the observations of the learned men of the
expeditions be so much better than those of any other clear-sighted
persons?” This is a perfectly fair question, and admits of a ready
answer. All that can be known by mere unprepared naked-eye observation
is tolerably well known already; the questions which await solution can
only be answered by putting the sun to torture by means of instruments
specially devised for that purpose; and by a skillful organization, and
division of labor among the observers.
There is so much to be seen during the few seconds of total obscuration
that no one human being, however well trained in the art of observing,
could possibly see all. Therefore it is necessary to pre-arrange each
observer’s part, to have careful rehearsals of what is to be done by
each during the precious seconds; and each man must exercise a vast
amount of self-control in order to confine his attention to his own
particular bit of observation, while he is surrounded with such
marvellous phenomena as a total eclipse presents.
The grandeur of the gloomy landscape, the sudden starting out of the
greater stars, the seeming falling of the vault of heaven, the silence
of the animal world, the closing of the flowers, and all that the
ordinary observer would regard with so much awe and wondering delight,
must be sacrificed by the philosopher, whose business is to confine
his gaze to a narrow slit between two strips of metal, and to watch
nothing else but the exact position and appearance of a few bright or
dark lines across what appears but a strip of colored riband. He must
resist the temptation to look aside and around with the stubbornness of
self-denial of another St. Antonio. Besides this, he must thoroughly
understand exactly what to look for, and how to find it. By combining
the results of his observations with those of the others, who in like
manner have undertaken to work with another instrument, or upon another
part of the phenomena, we get a scientific result comparable to that
which in a manufactory we obtain by the division of labor of many
skilled workmen, each doing only that which by his training he has
learned to do the best and the most expeditiously.
FURTHER DETAILS BY POST.
Although the formal official reports of the Eclipse Expedition are not
yet published, and may not be for some weeks or months, we are able
from the letters of Lockyer, Jannsen, Respighi, Maclear, etc., to form
some idea of the general results. We may already regard two or three
important questions as fairly answered. The reversal of the dark solar
lines of the spectrum which was first announced by the great Roman
observer, Father Secchi, and seen by him without an eclipse, may now
be considered as established. It is true that all the observers of
1871 did not witness this. Some were doubtful, but others observed it
positively and distinctly.
In such a case negative results do not refute the positive observations
of qualified men, especially when several of such observations have
been made independently; the phenomenon is but instantaneous, a mere
flash of bright stripes in place of dark lines across the colored
riband of the spectroscope, which happens just at the moment before and
after totality, and is presented only when the instrument is accurately
directed to the delicate curved vanishing thread of light which is the
last visible fragment of the solar outline, and that which makes the
first flash of his re-appearance.
A little explanation is necessary to render the significance of this
“reversal” intelligible to those who have not specially studied the
subject.
1st. When the spectroscope is directed to a luminous solid a simple
rainbow-band or “continuous spectrum” is seen. When, on the other hand,
the object is a luminous gas or vapor of moderate density, the spectrum
is not a continuous band with its colors actually blending; it consists
only of certain luminous stripes with blank spaces between them, each
particular gas or vapor showing its own particular set of stripes of
certain colors, and always appearing at exactly the same place, so
invariably and certainly, that, by means of such luminous stripes, the
composition of the gas or vapor may be determined. If, however, the gas
be much compressed, the stripes widen as the condensation proceeds;
they may even spread out sufficiently to meet and form a continuous
spectrum like that from a solid. Liquids also produce continuous
spectra.
2d. When a luminous solid or liquid, or very dense gas, capable of
producing a continuous spectrum, is viewed through an intervening body
of other gas or vapor of moderate or small density, fine _dark lines_
cross the spectrum in precisely the same places as the bright stripes
would appear if this intervening gas or vapor were luminous and seen by
itself.
When the spectroscope is directed to the face of the sun under ordinary
circumstances, it presents a brilliant continuous spectrum, striped
with a multitude of the dark lines. From this it has been inferred
that the luminous face of the sun is that of an incandescent solid
or liquid, and that it is surrounded by the gases and vapors whose
bright stripes, when artificially produced, occupy precisely the same
places as the dark lines of the solar spectrum. This was the theory
of Kirchoff and others in the early days of spectrum analysis, when
it was only known that solids and liquids were capable of producing a
continuous spectrum. The important discovery that gases and vapors,
if sufficiently condensed, will also produce a continuous spectrum,
opened another speculation, far more consistent with the other known
facts concerning the constitution of the sun, viz., that the sun may be
a great gaseous orb, blazing at its surface and gradually increasing in
density from the surface towards the centre.
According to this, the metals sodium, calcium, barium, magnesium,
iron, chromium, nickel, copper, zinc, strontium, cobalt, manganese,
aluminium, and titanium, whose vapors, with those of some few other
substances, give the dark lines that cross the solar spectrum, should
exist neither as solids nor liquids on the solar surface, but as
blazing gases. But such blazing gases, according to what I have stated
above, should give us bright stripes instead of dark lines. Why, then,
are not such bright stripes seen under ordinary circumstances?
This is easily answered. These blazing gases must, as we proceed from
the surface of the sun downwards, become so condensed by the pressure
of their own superincumbent strata, as to produce a continuous spectrum
of great brilliancy. With such a background the bright stripes would
be confounded and lost to sight. Besides this, the outer film of
cooler vapor through which our vision must necessarily penetrate
before reaching the luminous solar surface, will produce the dark
lines exactly where the bright stripes should be, and thus effectually
obliterate them; or, in other words, the intervening non-luminous
vapors are opaque to the particular rays of light which the bright
vapors of the same substance emits.
Therefore, according to this theory, if we could sweep away these
outside darkening vapors, and screen off the inner layers of denser
blazing matter which produces the continuous background, we should have
a spectrum displaying a multitude of bright stripes exactly where the
black lines of the ordinary solar spectrum appear.
Secchi announced that these bright lines were to be seen under
favorable circumstances, when, by skillful management, the rays from
the edge of the sun were so caught by the slit of the spectroscope as
to exhibit only the spectrum of the superficial layer of the sun’s
bright surface. This was disputed at the time by Mr. Lockyer, who, I
suspect, omitted to consider the atmospheric difficulties under which
English astronomers work, and the fact that the atmosphere of Italy is
exceptionally favorable for delicate astronomical observation.
If he had fairly considered this I think he would agree with me in
concluding that an observation of this kind, avowedly made with great
difficulty and questionable distinctness by so skillful a spectroscopic
observer as Father Secchi, could not possibly be seen by any human eyes
through a London atmosphere.
Subsequently Professor Young startled the astronomical world by the
announcement that, at the moment when the thinnest perceptible thread
of the sun’s edge was alone displayed during the eclipse which he
observed, the whole of the dark lines of the solar spectrum flashed
out as bright stripes in a most unmistakable manner. This observation
is now fully confirmed. The first telegrams from Mr. Pogson, the
Government astronomer of Madras, and from Colonel Tennant, both
announce this most positively, Colonel Tennant’s words being, “the
reversion of the lines fully confirmed.” A similar result was obtained
by some, but not by all, of the Ceylon observers.
To understand this clearly, we must consider the fact that what appears
to us as the outline of a flat disc is really that part of the sun
which we see by looking horizontally athwart his rotundity, just as
we look at the ocean surface of our own earth when we stand upon the
shore and see its horizon outline. When the moon obscures all but the
last film of this solar edge, we see only the surface of the supposed
gaseous orb, just that portion of the blazing gases which are not
greatly compressed by those above them, and which accordingly should,
if they consist of the vapors or the gases above named, display a
bright-striped spectrum, provided the intervening non-luminous vapors
of the same metals are not sufficiently abundant to obscure them—at
this particular moment, when only the absolute horizon-line is seen,
and the body of the moon cuts off all the intervening solar surface,
and the lower or denser portion of the intervening super-solar vapors,
though, of course, these are not so entirely cut off as the continuous
background.
The reversion of the dark lines therefore reveals to us the stupendous
fact that the surface of the mighty sun, which is as big as a million
and a quarter of our worlds, consists of a flaming ocean of hydrogen
and of the metals above-named in a gaseous condition, similar to that
of the hydrogen itself.
This fact, coupled with the other revelations of the spectroscope,
which, without the help of an eclipse, reveals the surface outline of
the sun, the “sierra” and the “prominences” tell us that this flaming
ocean is in a state of perpetual tempest, heaving up its billows and
flame-Alps hundreds and thousands of miles in height, and belching
forth above all these still taller pillars of fire that even reach an
elevation of more than a hundred thousand miles, and then burst out
into mighty clouds of flame and vapor, bigger than five hundred worlds.
What does the last eclipse teach us in reference to the corona? Firstly
and clearly, that Lockyer’s explanation which attributed it to an
illumination of the upper regions of the earth’s atmosphere must be
now forever abandoned. This theory has died hard, but, in spite of Mr.
Lockyer’s proclamation of “victory all along the line,” it is now past
galvanizing. There can be no further hesitation in pronouncing that the
corona actually belongs to the sun itself, that it is a marvelous solar
appendage extending from the sun in all directions, but by no means
regularly.
The immensity of this appendage will be best understood by the fact
that the space included within the outer limits of the visible corona
is at least twenty times as great as the bulk of the sun itself, that
above twenty-five millions of our worlds would be required to fill it.
Jannsen says: “I believe the question whether the corona is due to the
terrestrial atmosphere is settled, and we have before us the prospect
of the study of the extra-solar regions, which will be very interesting
and fertile.”
The spectroscope, the polariscope, and ordinary vision all concur
in supporting the explanation that the corona is composed of solid
particles and gaseous matter intermingled. It fulfils exactly all
the requirements of the hypothesis which attributes it to the same
materials as those which in a gaseous state cause the reversion of the
dark lines above described, but which have been ejected with the great
eruptions forming the solar prominences, and have become condensed into
glowing metallic hailstones as their distance from the central heat has
increased. These must necessarily be accompanied by the vapors of the
more volatile materials, and should give out some of the lighter gases,
such as hydrogen, which, under greater pressure, would be occluded
within them, just as the hydrogen gas occluded within the substance of
the Lenarto meteor (a mass of iron which fell from the sky upon the
earth) was extracted by the late Master of the Mint by means of his
mercurial air-pump.
The rifts or gaps between the radial streamers, which have been so
often described and figured, but were regarded by some as optical
illusions, are now established as unquestionable facts. Mr. Lockyer,
the last to be convinced, is now compelled to admit this, which
overthrows the supposition that this solar appendage is a luminous
solar atmosphere of any kind. If it were gaseous or true vapor, it must
obey the law of gaseous diffusion, and could not present the phenomena
of bright radial streamers, with dark spaces between them, unless it
were in the course of very rapid radial motion either to or from the
sun.
The photographs have not yet been published. When they have all
arrived, and can be compared, we shall learn something that I
anticipate will be extremely interesting respecting the changes of the
corona, as they have been taken at the different stations at different
times. I alluded to this subject before, when it was only a matter of
possibility that such a succession of pictures might have been taken.
We now have the assurance that such pictures have been obtained. There
can be no question about optical illusion in these; they are original
affidavits made by the corona itself, signed, sealed, and delivered as
its own act and deed.
METEORIC ASTRONOMY.
The number of the _Quarterly Journal of Science_ for May, 1872,
contains some articles of considerable interest. The first is by
the indefatigable Mr. Proctor, on “Meteoric Astronomy,” in which
he embodies a clear and popular summary of the researches which
have earned for Signor Schiaparelli this year’s gold medal of the
Astronomical Society. Like all who venture upon a broad, bold effort of
scientific thought, extending at all into the regions of philosophical
theory, Schiaparelli has had to wait for recognition. A simple and
merely mechanical observation of a bare fact, barely and mechanically
recorded without the exercise of any other of the intellectual
faculties than the external senses and observing powers, is at once
received and duly honored by the scientific world; but any higher
effort is received at first indifferently, or sceptically, and is only
accepted after a period of probation, directly proportionate to its
philosophical magnitude and importance, and inversely proportionate to
the scientific status of the daring theorist.
At first sight this appears unjust, it looks like honoring the laborers
who merely make the bricks, and despising the architect who constructs
the edifice of philosophy from the materials they provide. Many a
disappointed dreamer, finding that his theory of the universe has not
been accepted, and that the expected honors have not been showered
upon him, has violently attacked the whole scientific community
as a contemptible gang of low-minded mechanical plodders, void of
imagination, blind to all poetic aspirations, and incapable of any
grand and comprehensive flight of intellect.
Had these impulsive gentlemen been previously subjected to the strict
discipline of inductive scientific training, their position and
opinions would have been very different. Their great theories would
either have had no existence, or have been much smaller, and they
would understand that philosophic caution is one of the characteristic
results of scientific training.
Simple facts, which can be immediately proved by simple experiments
and simple observations, are at once accepted, and their discoverers
duly honored, without any hesitation or delay, but the grander efforts
of generalization require careful thought and laborious scrutiny for
their verification, and therefore the acknowledgment of their merits is
necessarily delayed; but when it does arrive full justice is usually
done.
Thus Grove’s “Correlation of the Physical Forces,” the greatest
philosophical work on purely physical science of this generation, was
commenced in 1842, when its author occupied but a humble position at
the London Institution. The book was but little noticed for many years,
and, had Mr. Grove (now Sir William Grove) not been duly educated
by the discipline above referred to, he might have become a noisy
cantankerous martyr, one of those “ill-used men” who have been made
familiar to so many audiences by Mr. George Dawson.
Instead of this, he patiently waited, and, as we have lately seen, the
well-deserved honors have now been liberally awarded.
In a very few years hence we shall be able to say the same of the once
diabolical Darwin, and eight or nine other theorists, who must all be
content to take their trial and patiently await the verdict; the time
of waiting being of necessity proportionate to the magnitude of the
issue.
The theories of Schiaparelli, which, as Mr. Proctor says, “after the
usual term of doubt have so recently received the sanction of the
highest astronomical tribunal of Great Britain,” are not of so purely
speculative a character as to demand a very long “term of doubt.” They
are directly based on observations and mathematical calculations which
bring them under the domain of the recognized logic of mathematical
probability. Those who are specially interested in the modern progress
of astronomy should read this article in the _Quarterly Journal of
Science_, which is illustrated with the diagrams necessary for the
comprehension of the researches and reasoning of Schiaparelli and
others who have worked on the same ground.
I can only state the general results, which are that the meteors which
we see every year, more or less abundantly, on the nights of the 10th
and 11th of August, and which always appear to come from the same point
in the heavens, are then and thus visible because they form part of an
eccentric elliptical zone of meteoric bodies which girdle the domain of
the sun; and that our earth, in the course of its annual journey around
the sun, crosses and plunges more or less deeply into this ellipse of
small attendant bodies, which are supposed to be moving in regular
orbits around the sun.
Schiaparelli has compared the position, the direction, and the velocity
of motion of the August meteors with the orbit of the great comet of
1862, and infers that there is a close connection between them, so
close that the meteors may be regarded as a sort of trail which the
comet has left behind. He does not exactly say that they are detached
vertebræ of the comet’s tail, but suggests the possibility of their
original connection with its head.
Similar observations have been made upon the November meteoric showers,
which by similar reasoning, are associated with another comet; and
further yet, it is assumed upon analogy that other recognized meteor
systems, amounting to nearly two hundred in number, are in like manner
associated with other comets.
If these theories are sound, our diagrams and mental pictures of the
solar system must be materially modified. Besides the central sun, the
eight planets and the asteroids moving in their nearly circular orbits,
and some eccentric comets traveling in long ellipses, we must add a
countless multitude of small bodies clustered in elliptical rings, all
traveling together in the path marked by their containing girdle, and
following the lead of a streaming vaporous monster, their parent comet.
We must count such comets, and such rings filled with attendant
fragments, not merely by tens or hundreds, but by thousands and tens of
thousands, even by millions; the path of the earth being but a thread
in space, and yet a hundred or two are strung upon it.
In this article Mr. Proctor seems strongly disposed to return to
the theory which attributes solar heat and light to a bombardment
of meteors from without, and the solar corona and zodiacal light as
visible presentments of these meteors. Still, however, he clings to the
more recent explanation which regards the corona, the zodiacal light,
and the meteors as matter ejected from the sun by the same forces as
those producing the solar prominences. For my own part I shall not
be at all surprised if we find that, ere long, these two apparently
conflicting hypotheses are fully reconciled.
The progress of solar discovery has been so great since January, 1870,
when my ejection theory was published, that I may now carry it out
much further than I then dared, or was justified in daring to venture.
Actual measurement of the projectile forces displayed in some of the
larger prominences renders it not merely possible, but even very
probable, that some of the exceptionally great eruptive efforts of the
sun may be sufficiently powerful to eject solar material beyond the
reclaiming reach of his own gravitating power.
In such a case the banished matter must go on wandering through the
boundless profundity of space until it reaches the domain of some other
sun, which will clutch the fragment with its gravitating energies,
and turn its straight and ever onward course into the curved orbit.
Thus the truant morsel from our sun will become the subject of another
sun—a portion of another solar system.
What one sun may do, another and every other may do likewise, and, if
so, there must be a mutual bombardment, a ceaseless interchange of
matter between the countless suns of the universe. This is a startling
view of our cosmical relations, but we are driving rapidly towards a
general recognition of it.
The November star showers have perpetrated some irregularities this
year. They have been very unpunctual, and have not come from their
right place. We have heard something from Italy, but not the tidings of
the Leonides that were expected. Instead of the great display of the
month occurring on the 13th and 14th, it was seen on the 27th. We have
accounts from different parts of England, Ireland, Scotland, and Wales,
also from Italy, Greece, Egypt, etc.
Mr. Slinto, in a letter to the _Times_, estimates the number seen at
Suez as reaching at least 30,000, while in Italy and Athens about 200
per minute were observed. They were not, however, the Leonides, that
is, they did not radiate from a point in the constellation Leo, but
from the region of Andromeda. Therefore they were distinct from that
system of small wanderers usually designated the “November meteors,”
were not connected with Tempel’s comet (comet 1, 1866), but belong to
quite another set.
The question now discussed by astronomers is whether they are connected
with any other comet, and, if so, with which comet?
In the “Monthly Notices” of the Royal Astronomical Society, published
October 24th last, is a very interesting paper by Professor Herschel,
on “Observations of Meteor Showers,” supposed to be connected with
“Biela’s comet,” in which he recommends that “a watch should be kept
during the last week in November and the first week in December,”
in order to verify “the ingenious suggestions of Dr. Weiss,” which,
popularly stated, amount to this, viz., that a meteoric cloud is
revolving in the same orbit as Biela’s comet, and that in 1772 the
earth dashed through this meteoric orbit on December 10th. In 1826 it
did the same, on December 4th; in 1852 the earth passed through the
node on November 28th, and there are reasons for expecting a repetition
at about the same date in 1872.
The magnificent display of the 27th has afforded an important
verification of these anticipations, which become especially
interesting in connection with the curious history of Biela’s comet,
which receives its name from M. Biela, of Josephstadt, who observed it
in 1826, calculated its orbit, and considered it identical with the
comets of 1772, 1805, etc. It travels in a long eccentric ellipse, and
completes its orbit in 2410 days—about 6¾ years. It appeared again, as
predicted, in 1832 and 1846.
Its orbit very nearly intersects that of the earth, and thus affords
a remote possibility of that sort of collision which has excited so
much terror in the minds of many people, but which an enthusiastic
astronomer of the present generation would anticipate with something
like the sensational interest which stirs the soul of a London
street-boy when he is madly struggling to keep pace with a fire-engine.
The calculations for 1832 showed that this comet should cross the
earth’s orbit a little before the time of the earth’s arrival at the
same place; but as such a comet, traveling in such an orbit, is liable
to possible retardations, the calculations could only be approximately
accurate, and thus the sensational astronomer was not altogether
without hope. This time, however, he was disappointed; the comet was
punctual, and crossed the critical node about a month before the earth
reached it.
As though to compensate for this disappointment, the comet at its next
appearance exhibited some entirely new phenomena. It split itself into
two comets, in such a manner that the performance was visible to the
telescopic observer. Both of these comets had nuclei and short tails,
and they alternately varied in brightness, sometimes one, then the
other, having the advantage. They traveled on at a distance of about
156,000 miles from each other, with parallel tails, and with a sort
of friendly communication in the form of a faint arc of light, which
extended as a kind of bridge, from one to the other. Besides this, the
one which was first the brighter, then the fainter, and finally the
brighter again, threw out two additional tails, one of which extended
lovingly towards its companion.
The time of return in 1852 was of course anxiously expected by
astronomers, and careful watch was kept for the wanderers. They came
again at the calculated time, still separated as before.
They were again due in 1859, in 1866, and, finally, at about the end of
last November, or the beginning of the present month. Though eagerly
looked for by astronomers in all parts of the civilized world, they
have been seen no more since 1852.
What, then, has become of them? Have they further subdivided? Have they
crumbled into meteoric dust? Have they blazed or boiled into thin air?
or have they been dragged by some interfering gravitation into another
orbit? The last supposition is the most improbable, as none of the
visible inhabitants of space have come near enough to disturb them.
The possibility of a dissolution into smaller fragments is suggested
by the fact that, instead of the original single comet, or the two
fragments, meteoric showers have fallen towards the earth at the time
when it has crossed the orbit of the original comet, and these showers
have radiated from that part of the heavens in which the comet should
have appeared. Such was the case with the magnificent display of
November 27th, and astronomers are inclining more and more to the idea
that comets and meteors have a common origin—the meteors are little
comets, or comets are big meteors.
In the latest of the “Monthly Notices,” of the Royal Astronomical
Society, published last week, is a paper by Mr. Proctor, in which he
expands the theory expounded three years ago by an author whom your
correspondent’s modesty prevents him from naming, viz., that the larger
planets—Jupiter, Saturn, Uranus, and Neptune—are minor suns, ejecting
meteoric matter from them by the operation of forces similar to those
producing the solar prominences.
Mr. Proctor subjects this bold hypothesis to mathematical examination,
and finds that the orbit of Tempel’s comet and its companion meteors
correspond to that which would result from such an eruption occurring
on the planet Uranus. An eruptive force effecting a velocity of about
thirteen miles per second, which is vastly smaller than the actually
measured velocity of the matter of the solar eruptions, would be
sufficient to thrust such meteoric or cometary matter beyond the
reclaiming reach of the gravitation of Uranus, and hand it over to the
sun, to make just such an orbit as that of Tempel’s comet and the
Leonides meteors.
He shows that other comets and meteoric zones are similarly allied to
other planets, and thus it may be that the falling stars and comets
are fragments of Jupiter, Saturn, Uranus, or Neptune. Verily, if an
astronomer of the last generation were to start up among us now, he
would be astounded at modern presumption.
The star shower of November 27th, and its connection with Biela’s
broken and lost comet, referred to in my last letter, are still
subjects of research and speculation. On November 30th Professor
Klinkerfues sent to Mr. Pogson, of the Madras Observatory, the
following startling telegram: “Biela touched earth on 27th. Search near
Theta Centauri.”
Mr. Pogson searched accordingly from comet-rise to sunrise on the two
following mornings, but in vain; for even in India they have had cloudy
weather of late. On the third day, however, he had “better luck,” saw
something like a comet through an opening between clouds, and on the
following days was enabled to deliberately verify this observation and
determine the position and some elements of the motion of the comet,
which displayed a bright nucleus, and faint but distinct tail.
This discovery is rather remarkable in connection with the theoretical
anticipation of Professor Klinkerfues; but the conclusion directly
suggested is by no means admitted by astronomers. Some, have supposed
that it is not the primary Biela, but the secondary comet, or offshoot,
which grazed the earth, and was seen by Mr. Pogson; others that it was
neither the body, the envelope, nor the tail of either of the comets
which formed the star shower, but that the meteors of November 27th
were merely a trail which the comet left behind.
A multitude of letters were read at the last and previous meeting of
the Astronomical Society, in which the writers described the details
of their own observations. As these letters came from nearly all parts
of the world, the data have an unusual degree of completeness, and
show very strikingly the value of the work of amateur astronomical
observers.
By the collation and comparison of these, important inductions are
obtainable. Thus Professor A. S. Herschel concludes that the earth
passed through seven strata of meteoric bodies, having each a thickness
of about 50,000 miles—in all about 350,000 miles. As the diameter
of the visible nebulosity of Biela’s comet was but 40,000 miles
when nearest the earth in 1832, the great thickness of these strata
indicates something beyond the comet itself.
Besides this, Mr. Hind’s calculation for the return of the primary
comet shows that on November 27th it was 250 millions of miles from the
earth.
Those, however, who are determined to enjoy the sensation of supposing
that they really have been brushed by the tail of a comet, still have
the secondary comet to fall back upon. This, as already described, was
broken off the original, from which it was seen gradually to diverge,
but was still linked to it by an arch of nebulous matter.
If this divergence has continued, it must now be far
distant—sufficiently far to afford me an opportunity of safely adding
another to the numerous speculations, viz., that we may, on November
27th, have plunged obliquely through this connecting arm of nebulous
matter, which was seen stretching between the parent comet and its
offshoot. The actual position of the meteoric strata above referred to
is quite consistent with the hypothesis.
THE “GREAT ICE AGE” AND THE ORIGIN OF THE “TILL.”
The growth of science is becoming so overwhelming that the old
subdivisions of human knowledge are no longer sufficient for the
purpose of dividing the labor of experts. It is scarcely possible now
for any man to become a naturalist, a chemist, or a physicist in the
full sense of either term; he must, if he aims at thoroughness, be
satisfied with a general knowledge of the great body of science, and
a special and a full acquaintance with only one or two of its minor
subdivisions. Thus geology, though but a branch of natural history,
and the youngest of its branches, has now become so extensive that its
ablest votaries are compelled to devote their best efforts to the study
of sections which but a few years ago were scarcely definable.
Glaciation is one of these, which now demands its own elementary
text-books over and above the monographs of original investigators.
This demand has been well supplied by Mr. James Geikie in the “The
Great Ice Age,”[15] of which a second edition has just been issued.
Every student of glacial phenomena owes to Mr. Geikie a heavy debt
of gratitude for the invaluable collection of facts and philosophy
which this work presents. It may now be fairly described as a standard
treatise on the subject which it treats.
One leading feature of the work offers a very aggressive invitation to
criticism. Scotchmen are commonly accused of looking upon the whole
universe through Scotch spectacles, and here we have a Scotchman
treating a subject which affects nearly the whole of the globe, and
devoting about half of his book to the details of Scottish glacial
deposits; while England has but one-third of the space allowed to
Scotland, Ireland but a thirtieth, Scandinavia less than a tenth, North
America a sixth, and so on with the rest of the world. Disproportionate
as this may appear at first glance, further acquaintance with the work
justifies the pre-eminence which Mr. Geikie gives to the Scotch glacial
deposits. Excepting Norway, there is no country in Europe which affords
so fine a field for the study of the vestiges of extinct glaciers as
Scotland, and Scotland has an advantage even over Norway in being much
better known in geological detail. Besides this, we must always permit
the expounder of any subject to select his own typical illustrations,
and welcome his ability to find them in a region which he himself has
directly explored.
Mr. Geikie’s connection with the geological survey of Scotland has
afforded him special facilities for making good use of Scottish typical
material, and he has turned these opportunities to such excellent
account that no student after reading “The Great Ice Age” will find
fault with its decided nationality.
The leading feature—the basis, in fact—of this work deserves especial
notice, as it gives it a peculiar and timely value of its own. This
feature is that the subject—as compared with its usual treatment by
other leading writers—is turned round and presented, so to speak,
bottom upwards. De Saussure, Charpentier, Agassiz, Humboldt, Forbes,
Hopkins, Whewell, Stark, Tyndall, etc., have studied the living
glaciers, and upon the data thus obtained have identified the work
of extinct glaciers. Chronologically speaking, they have proceeded
backwards, a method absolutely necessary in the early stages of the
inquiry, and which has yielded admirable results. Geikie, in the work
before us, proceeds exactly in the opposite order. Availing himself
of the means of identifying glacial deposits which the retrogressive
method affords, he plunges at once to the lowest and oldest of these
deposits, which he presents the most prominently, and then works
upwards and onwards to recent glaciation.
The best illustration I can offer of the timely advantage of this
reversed treatment is (with due apology for necessary egotism) to
state my own case. In 1841, when the “glacial hypothesis,” as it was
then called, was in its infancy, Professor Jamieson, although very
old and nearly at the end of his career, took up the subject with
great enthusiasm, and devoted to it a rather disproportionate number
of lectures during his course on Natural History. Like many of his
pupils, I became infected by his enthusiasm, and went from Edinburgh
to Switzerland, where I had the good fortune to find Agassiz and his
merry men at the “Hotel des Neufchatelois”—two tents raised upon a
magnificent boulder floating on the upper part of the Aar glacier.
After a short but very active sojourn there I “did,” not without
physical danger, many other glaciers in Switzerland and the Tyrol, and
afterwards practically studied the subject in Norway, North Wales, and
wherever else an opportunity offered, reading in the meantime much of
its special literature; but, like many others, confining my reading
chiefly to authors who start with living glaciers and describe their
doings most prominently. When, however, I read the first edition of
Mr. Geikie’s “Great Ice Age,” immediately after its publication, his
mode of presenting the phenomena, bottom upwards, suggested a number
of reflections that had never occurred before, leading to other than
the usual explanations of many glacial phenomena, and correcting some
errors into which I had fallen in searching for the vestiges of ancient
glaciers. As these suggestions and corrections may be interesting to
others, as they have been to myself, I will here state them in outline.
The most prominent and puzzling reflection or conclusion suggested
by reading Mr. Geikie’s description of the glacial deposits of
Scotland was, that the great bulk of them are quite different from the
deposits of existing glaciers. This reminded me of a previous puzzle
and disappointment that I had met in Norway, where I had observed
such abundance of striation, such universality of polished rocks and
rounded mountains, and so many striking examples of perched blocks,
with scarcely any decent vestiges of moraines. This was especially
the case in Arctic Norway. Coasting from Trondhjem to Hammerfest,
winding round glaciated islands, in and out of fjords banked with
glaciated rock-slopes, along more than a thousand miles of shore line,
displaying the outlets of a thousand ancient glacier valleys, scanning
eagerly throughout from sea to summit, landing at several stations,
and climbing the most commanding hills, I _saw only one ancient
moraine_—that at the Oxfjord station described in “Through Norway with
Ladies.”[16]
But this negative anomaly is not all. The ancient glacial deposits
are not only remarkable on account of the absence of the most
characteristic of modern glacial deposits, but in consisting mainly of
something which is quite different from any of the deposits actually
formed by any of the modern glaciers of Switzerland or any other
country within the temperate zones.
I have seen nothing either at the foot or the sides of any living
Alpine or Scandinavian glacier that even approximately represents the
“till” or “boulder clay,” nor any description of such a formation by
any other observer; and have met with no note of this very suggestive
anomaly by any writer on glaciers. Yet the till and boulder clay form
vast deposits, covering thousands of square miles even of the limited
area of the British Isles, and constitute the main evidence upon which
we base all our theories respecting the existence and the vast extent
and influence of the “Great Ice Age.”
Although so different from anything at present produced by the Alpine
or Scandinavian glaciers, this great deposit is unquestionably of
glacial origin. The evidences upon which this general conclusion
rests are fully stated by Mr. Geikie, and may safely be accepted as
incontrovertible. Whence, then, the great difference?
One of the suggestions to which I have already alluded as afforded
by reading Mr. Geikie’s book was a hypothetical solution of this
difficulty, but the verification of the hypothesis demanded a re-visit
to Norway. An opportunity for this was afforded in the summer of 1874,
during which I traveled round the coast from Stavanger to the Arctic
frontier of Russia, and through an interesting inland district. The
observations there made and strengthened by subsequent reflections,
have so far confirmed my original speculative hypothesis that I now
venture to state it briefly as follows:
That the period appropriately designated by Mr. Geikie as the “Great
Ice Age” includes at least two distinct periods or epochs—the first
of very great intensity or magnitude, during which the Arctic regions
of our globe were as completely glaciated as the Antarctic now are,
and the British islands and a large portion of Northern Europe were
glaciated as completely, and nearly in the same manner, as Greenland is
at the present time; that long after this, and immediately preceding
the present geological epoch, there was a minor glacial period, when
only the now existing valleys, favorably shaped and situated for
glacial accumulations, were partially or wholly filled with ice. There
may have been many intermediate fluctuations of climate and glaciation,
and probably were such, but as these do not affect my present argument
they need not be here considered.
So far I agree with the general conclusions of Mr. Geikie as I
understand them, and with the generally received hypotheses, but in
what follows I have ventured to diverge materially.
It appears to me that the existing Antarctic glaciers and some of the
glaciers of Greenland are essentially different in their conformation
from the present glaciers of the Alps, and from those now occupying
some of the fjelds and valleys of Norway; and that the glaciers of the
earlier or greater glacial epoch were similar to those now forming the
Antarctic barrier, while the glaciers of the later or minor glacial
epoch resembled those now existing in temperate climates, or were
intermediate between these and the Antarctic glaciers. The nature
of the difference which I suppose to exist between the two classes
of glaciers is this: The glaciers (properly so called) of temperate
climates are the overflow of the _nevé_ (the great reservoir of ice and
snow above the snow line). They are composed of ice which is protruded
below the snow-line into the region where the summer thaw exceeds the
winter snow-fall. This ice is necessarily subject to continual thinning
or wasting from its _upper_ or exposed surface, and thus finally
becomes liquefied, and is terminated by direct solar action.
Many of the characteristic phenomena of Alpine glaciers depend upon
this; among the more prominent of which are the superficial extrusion
of boulders or rock fragments that have been buried in the _nevé_ or
have fallen into the crevasses of the upper part of the true glacier,
and the final deposit of these same boulders of fragments at the foot
of the glaciers forming ordinary moraines.
But this is not all. The thawing which extrudes, and finally deposits
the larger fragments of rock, sifts from them the smaller particles,
the aggregate bulk of which usually exceeds very largely that of the
larger fragments. This fine silt or sand thus washed away is carried by
the turbid glacier torrent to considerable distances, and deposited as
an alluvium wherever the agitated waters find a resting-place.
Thus the _débris_ of the ordinary modern glacier is effectively
separated into two or more very distinct deposits; the moraine at the
glacier foot consisting of rock fragments of considerable size with
very little sand or clay or other fine deposit between them, and a
distant deposit of totally different character, consisting of gravel,
sand, clay, or mud, according to the length and conditions of its
journey. The “chips,” as they have been well called, are thus separated
from what I may designate the _filings_ or _sawdust_ of the glacier.
The filings from the existing glaciers of the Bernese Alps are
gradually filling up the lake-basins of Geneva and Constance,
repairing the breaches made by the erosive action of their gigantic
predecessors; those of the southern slope of the Alps are doing a large
share in filling up the Adriatic; while the chips of all merely rest
upon the glacier beds forming the comparatively insignificant terminal
moraine deposits.
The same in Scandinavia. The Storelv of the Jostedal is fed by the
melting of the Krondal, Nygaard, Bjornestegs, and soldal glaciers. It
has filled up a branch of the deep Sogne fjord, forming an extensive
fertile plain at the mouth of its wild valley, and is depositing
another subaqueous plain beyond, while the moraines of the glaciers
are but inconsiderable and comparatively insignificant heaps of
loose boulders, spread out on the present and former shores of the
above-named glaciers, which are overflows from one side of the great
_nevé_, the Jostedal Sneefond. All of these glaciers flow down small
lateral valleys, spread out, and disappear in the main valley, which
has now no glacier of its own, though it was formerly glaciated
throughout.
What must have been the condition of this and the other great
Scandinavian valleys when such was the case? To answer this question
rationally we must consider the meteorological conditions of that
period. Either the climate must have been much colder, or the amount of
precipitation vastly greater than at present, in order to produce the
general glaciation that rounded the mountains up to a height of some
thousands of feet above the present sea-level. Probably both factors
co-operated to effect this vast glaciation, the climate colder, and the
snow-fall also greater. The whole of Scandinavia, or as much as then
stood above the sea, must have been a _nevé_ or sneefond on which the
annual snow-fall exceeded the annual thaw.
This is the case at present on the largest _nevé_ of Europe, the 500
square miles of the great plateau of the Jostedals and Nordfjords
Sneefond, on all the overflowing _nevé_ or snow-fields of the Alps
above the snow-line; over the greater part of Greenland; and (as the
structure of the southern icebergs prove) everywhere within the great
Antarctic ice barrier.
What, then, must happen when the snow-line comes down, or nearly down,
to the sea-level? It is evident that the out-thrust glaciers, the
overflow down the valleys, cannot come to an end like the present Swiss
and Scandinavian glaciers, by the direct melting action of the sun.
They may be somewhat thinned from below by the heat of the earth, and
that generated by their own friction on the rocks, but these must be
quite inadequate to overcome the perpetual accumulation due to the
snow-fall upon their own surface and the vast overflow from the great
snow-fields above. They must go on and on, ever increasing, until they
meet some new condition of climate or some other powerful agent of
dissipation—something that can effectively melt them.
This agent is very near at hand in the case of the Scandinavian valleys
and those of Scotland. It is the sea. I think I may safely say that the
valley glaciers of these countries during the great ice age _must_ have
reached the sea, and there have terminated their existence, just as the
Antarctic glaciers terminate at the present Antarctic ice-wall.
What must happen when a glacier is thus thrust out to sea? This
question is usually answered by assuming that it slides along the
bottom until it reaches such a depth that flotation commences and
then it breaks off or “calves” as icebergs. This view is strongly
expressed by Mr. Geikie (p. 47) when he says that—“The seaward portion
of an Arctic glacier cannot by any possibility be floated up without
sundering its connection with the frozen mass behind. So long as the
bulk of the glacier much exceeds the depth of the sea, the ice will of
course rest upon the bed of the fjord or bay without being subjected to
any strain or tension. But when the glacier creeps outwards to greater
depths, then the superior specific gravity of the sea-water will tend
to press the ice upward. That ice, however, is a hard continuous mass,
with sufficient cohesion to oppose for a time this pressure, and hence
the glacier crawls on to a depth far beyond the point at which, had it
been free, it would have risen to the surface and floated. If at this
great depth the whole mass of the glacier could be buoyed up without
breaking off, it would certainly go to prove that the ice of Arctic
regions, unlike ice anywhere else, had the property of yielding to
mechanical strain without rupturing. But the great tension to which it
is subjected takes effect in the usual way, and the ice yields, not by
bending and stretching, but by breaking.” Mr. Geikie illustrates this
by a diagram showing the “calving” of an iceberg.
In spite of my respect for Mr. Geikie as a geological authority, I
have no hesitation in contradicting some of the physical assumptions
included in the above.
Ice has no such rigidity as here stated. It _does_ possess in a
high degree “the property of yielding to mechanical strain without
rupturing.” We need not go far for evidence of this. Everybody who has
skated or seen others skating on ice that is but just thick enough to
“bear” must have felt or seen it yield to the mechanical strain of the
skater’s weight. Under these conditions it not only bends under him,
but it afterwards yields to the reaction of the water below, rising
and falling in visible undulations, demonstrating most unequivocally a
considerable degree of flexibility. It may be said that in this case
the flexibility is due to the thinness of the ice; but this argument
is unsound, inasmuch as the manifestation of such flexibility does
not depend upon absolute thickness or thinness, but upon the relation
of thickness to superficial extension. If a thin sheet of ice can be
bent to a given arc, a thick sheet may be bent in the same degree, but
the thicker ice demands a greater radius and proportionate extension
of circumference. But we have direct evidence that ice of great
thickness—actual glaciers—may bend to a considerable curvature before
breaking. This is seen very strikingly when the uncrevassed ice-sheet
of a slightly inclined _nevé_ suddenly reaches a precipice and is
thrust over it. If Mr. Geikie were right, the projecting cornice thus
formed should stand straight out, and then, when the transverse strain
due to the weight of this rigid overhang exceeded the resistance of
tenacity, it should break off short, exposing a face at right angles
to the general surface of the supported body of ice. Had Mr. Geikie
ever seen and carefully observed such an overhang or cornice of ice, I
suspect that the above-quoted passage would not have been written.
Some very fine examples of such ice-cornices are well seen from the
ridge separating the Handspikjen Fjelde from the head of the Jostedal,
where a view of the great _nevé_ or sneefond is obtained. This side of
the _nevé_ terminates in precipitous rock-walls; at the foot of one of
these is a dreary lake, the Styggevand. The overflow of the _nevé_ here
forms great bending sheets that reach a short way down, and then break
off and drop as small icebergs into the lake.[17]
The ordinary course of glaciers affords abundant illustrations of
the plasticity of such masses of ice. They spread out where the
valley widens, contract where the valley narrows, and follow all
the convexities or concavities of the axial line of its bed. If the
bending thus enforced exceeds a certain degree of abruptness crevasses
are formed, but a considerable bending occurs before the rupture is
effected, and crevasses of considerable magnitude are commonly formed
without severing one part of a glacier from another. They are usually
=V=-shaped, in vertical section, and in many the rupture does not reach
the bottom of the glacier. Very rarely indeed does a crevasse cross the
whole breadth of a glacier in such a manner as to completely separate,
even temporarily, the lower from the upper part of the glacier.
If a glacier can thus bend _downwards_ without “sundering its
connection with the frozen mass behind,” surely it may bend upwards
in a corresponding degree, either with or without the formation of
crevasses, according to the thickness of the ice and the degree of
curvature.
A glacier reaching the sea by a very steep incline would probably
break off, in accordance with Mr. Geikie’s description, just as an
Alpine glacier is ruptured fairly across when it makes a cascade over
a suddenly precipitous bend of its path. One entering the sea at an
inclination somewhat less precipitous than the minor limit of the
effective rupture gradient would be crevassed in a contrary manner to
the crevassing of Alpine glaciers. Its crevasses would gape downwards
instead of upwards—have =Λ=-shaped instead of a =V=-shaped section.
With a still more moderate slope, the up-floating of the termination
of the glacier, and a concurrent general up-lifting or upbending of
the whole of its submerged portion might occur without even a partial
rupture or crevasse formation occurring.
Let us now follow out some of the necessary results of these conditions
of glacier existence and glacial prolongation. The first and most
notable, by its contrast with ordinary glaciers, is the absence of
lateral, medial, or terminal moraines. The larger masses of _débris_,
the chippings that may have fallen from the exposed escarpments of
the mountains upon the surface of the upper regions of the glacier,
instead of remaining on the surface of the ice and standing above its
general level by protecting the ice on which they rest from the general
snow-thaw, would become buried by the upward accretion of the ice due
to the unthawed stratum of each year’s snow-fall.
The thinning agency at work upon such glaciers during their journey
over the _terra firma_ being the outflow of terrestrial heat and
that due to their friction upon their beds, this thinning must all
take place from below, and thus, as the glaciers proceed downwards,
these rock fragments must be continually approaching the bottom
instead of continually approaching the top, as in the case of modern
Alpine glaciers flowing below the snow-line, and thawing from surface
downwards.
It follows, therefore, that such glaciers could not deposit any
moraines such as are in course of deposition by existing Alpine and
Scandinavian glaciers.
What, then, must become of the chips and filings of these outfloating
glaciers? They must be carried along with the ice _so long as that
ice rests upon the land_; for this _débris_ must consist partly of
fragments imbedded in the ice, and partly of ground and re-ground
excessively subdivided particles, that must either cake into what I may
call ice-mud, and become a part of the glacier, or flow as liquid mud
or turbid water beneath it, as with ordinary glaciers. The quantity of
water being relatively small under the supposed conditions, the greater
part would be carried forward to the sea by the ice rather than by the
water.
An important consequence of this must be that the erosive power of
these ancient glaciers was, _cæteris paribus_, greater than that of
modern Alpine glaciers, especially if we accept those theories which
ascribe an actual internal growth or regeneration of glaciers by the
relegation below of some of the water resulting from the surface-thaw.
As the glacier with its lower accumulation advances into deeper and
deeper water, its pressure upon its bed must progressively diminish
until it reaches a line where it would just graze the bottom with a
touch of feathery lightness. Somewhere before reaching this it would
begin to deposit its burden on the sea-bottom, the commencement of
this deposition being determined by the depth whereat the tenacity of
the deposit, or its friction against the sea-bottom, or both combined,
becomes sufficient to overpower the now-diminished pressure and forward
thrusting, or erosive power of the glacier.
Further forward, in deeper water, where the ice becomes fairly floated
above the original sea-bottom, a rapid under-thawing must occur by the
action of the sea-water, and if any communication exists between this
ice covered sea and the waters of warmer latitudes this thawing must
be increased by the currents that would necessarily be formed by the
interchange of water of varying specific gravities. Deposition would
thus take place in this deeper water, continually shallowing it or
bringing up the sea-bottom nearer to the ice-bottom.
This raising of the sea-bottom must occur not only here, but farther
back, _i.e._, from the limit at which deposition commenced. This
neutral ground, whereat the depth is just sufficient to allow the
ice to rest lightly on its own deposit and slide over it without
either sweeping it forward or depositing any more upon it, becomes an
interesting critical region, subject to continuous forward extension
during the lifetime of the glacier, as the deposition beyond it must
continually raise the sea-bottom until it reaches the critical depth
at which the deposition must cease. This would constitute what I may
designate the normal depth of the glaciated sea, or the depth towards
which it would be continually tending, during a great glacial epoch,
by the formation of a submarine bank or plain of glacier deposit,
over which the glacier would slide without either grinding it lower by
erosion or raising it higher by deposition.
But what must be the nature of this deposit? It is evident that it
cannot be a mere moraine consisting only of the larger fragments of
rock such as are now deposited at the foot of glaciers that die out
before reaching the sea. Neither can it correspond to the glacial silt
which is washed away and separated from these larger fragments by
glacial streams, and deposited at the outspreadings of glacier torrents
and rivers. It will correspond to neither the assorted gravel, sand,
nor mud of these alluvial deposits, but must be an agglomeration of all
the infusible solid matter the glacier is capable of carrying.
It must contain, in heterogeneous admixture, the great boulders, the
lesser rock fragments, the gravel chips, the sand, and the slimy mud;
these settling down quietly in the cold, gloomy waters, overshadowed by
the great ice-sheet, must form just such an agglomeration as we find in
the boulder clay and tills, and lie just in those places where these
deposits abound, provided the relative level of land and sea during the
glacial epoch were suitable.
I should make one additional remark relative to the composition of
this deposit, viz., that under the conditions supposed, the original
material detached from the rocks around the upper portions of the
glaciers would suffer a far greater degree of attrition at the glacier
bottom than it obtains in modern Alpine glaciers, inasmuch as in these
it is removed by the glacier torrent when it has attained a certain
degree of fineness, while in the greater glaciers of the glacial epoch
it would be carried much further in association with the solid ice, and
be subjected to more grinding and regrinding against the bottom. Hence
a larger proportion of slimy mud would be formed, capable of finally
induring into stiff clay such as forms the matrix of the till and
boulder clay.
The long journey of the bottom _débris_ stratum of the glacier, and its
final deposition when in a state of neutral equilibrium between its
own tendency to repose and the forward thrust of the glacier, would
obviously tend to arrange the larger fragments of rock in the manner
in which they are found imbedded in the till, _i.e._, the oblong
fragments lying with their longer axes and their best marked striæ in
the direction of the motion of the glacier. The “_striated pavements_”
of the till are thus easily explained; they are the surface upon which
the ice advanced when its deposits had reached the critical or neutral
height. Such a pavement would continually extend outwards.
The only sorting of the material likely to occur under these conditions
would be that due to the earlier deposition and entanglement of the
larger fragments, thus producing a more stony deposit nearer inland,
just as Mr. Geikie describes the actual deposits of till where,
“generally speaking, the stones are most numerous in the till of
hilly districts; while at the lower levels of the country the clayey
character of the mass is upon the whole more pronounced.” These “hilly
districts,” upon the supposition of greater submergence, would be the
near shore regions, and the lower levels the deeper sea where the
glacier floated freely.
The following is Mr. Geikie’s description of the distribution of the
till (page 13):—“It is in the lower-lying districts of the country
where till appears in greatest force. Wide areas of the central
counties are covered up with it continuously, to a depth varying
from two or three feet up to one hundred feet and more. But as we
follow it towards the mountain regions it becomes thinner and more
interrupted—the naked rock ever and anon peering through, until at
last we find only a few shreds and patches lying here and there in
sheltered hollows of the hills. Throughout the Northern Highlands it
occurs but rarely, and only in little isolated patches. It is not
until we get way from the steep rocky declivities and narrow glens and
gorges, and enter upon the broader valleys that open out from the base
of the highland mountains to the low-lying districts beyond, that we
meet with any considerable deposits of stony clay. The higher districts
of the Southern Uplands are almost equally free from any covering of
till.”
This description is precisely the same as I must have written, had I so
far continued my imaginary sketch of the results of ancient glaciation
as to picture what must remain after the glaciers had all melted away,
and the sea had receded sufficiently to expose their submarine deposits.
Throughout the above I have assumed a considerable submergence of the
land as compared with the present sea-level on the coasts of Scotland,
Scandinavia, etc.
The universality of the terraces in all the Norwegian valleys opening
westward proves a submergence of _at least_ 600 or 700 feet. When I
first visited Norway in 1856, I accepted the usual description of these
as alluvial deposits; was looking for glacial vestiges in the form of
moraines, and thus quite failed to observe the true nature of these
vast accumulations, which was obvious enough when I re-examined them in
the light of more recent information. Some few are alluvial, but they
are exceptional and of minor magnitude. As an example of such alluvial
terraces I may mention those near the mouth of the Romsdal, that are
well seen from the Aak Hotel, and which a Russian prince, or other
soldier merely endowed with military eyes, might easily mistake for
artificial earthworks erected for the defence of the valley.
In this case, as in the others where the terraces are alluvial, the
valley is a narrow one, occupied by a relatively wide river loaded with
recent glacial _débris_. It evidently filled the valley during the
period of glacial recession.
The ordinary wider valleys, with a river that has cut a narrow
channel through the outspread terrace-flats, display a different
formation. Near the mouth of such valleys I have seen cuttings of
more than a hundred feet in depth, through an unbroken terrace of
most characteristic till, with other traces rising above it. This
is the ordinary constitution of the _lower portions_ of most of the
Scandinavian terraces.
These terraces are commonly topped with quite a different stratum,
which at first I regarded as a subsequent alluvial or estuarine
deposit, but further examination suggested another explanation of the
origin of some portions of this superficial stratum, to which I shall
refer hereafter.
Such terraces prove a rise of sea or depression of land, during
the glacial epoch, to the extent of 600 feet as a _minimum_, while
the well-known deposits of Arctic shells at Moel Tryfaen and the
accompanying drift have led Prof. Ramsay to estimate “the probable
amount of submergence during some part of the glacial period at about
2300 feet.”[18]
It would be out of place here to reproduce the data upon which
geologists have based their rather divergent opinions respecting the
actual extent of the submergence of the western coast of North Europe.
All agree that a great submergence occurred, but differ only as to its
extent, their estimates varying between 1,000 and 3,000 feet.
There is one important consideration that must not be overlooked, viz.,
that—if my view of the submarine origin of the till be correct—the
mere submergence of the land at the glacial period does not measure the
difference between the depth of the sea at that and the present time,
seeing that the deposits from the glaciers must have shallowed it very
materially.
It is only after contemplating thoroughly the present form of the
granitic and metamorphic hills of Scandinavia,—hills that are always
angular when subjected only to subaerial weathering,—that one can form
an adequate conception of the magnitude of this shallowing deposit. The
rounding, shaving, grinding, planing, and universal abrasion everywhere
displayed appear to me to justify the conclusion that if the sea were
now raised to the level of the terraces, _i.e._, 600 feet higher than
at present, the mass of matter abraded from the original Scandinavian
mountains, and lying under the sea, would exceed the whole mass of
mountain left standing above it.
The first question suggested by reading Mr. Geikie’s book was whether
the terraces are wholly or partially formed of till, and more
especially whether their lower portions are thus composed. This, as
already stated, was easily answered by the almost unanimous reply of
all the many Norwegian valleys I traversed. Any tourist may verify
this. The next question was whether this same till extends below the
sea. This was not so easily answered by the means at my disposal, as I
travelled hastily round the coast from Stavanger via the North Cape to
the frontier of Russian Lapland in ordinary passenger steam-packets,
which made their stoppages to suit other requirements than mine. Still,
I was able to land at many stations, and found, wherever there was
a gently sloping strand at the mouth of an estuary, or of a valley
whose river had already deposited its suspended matter (a common case
hereabouts, where so many rivers terminate in long estuaries or open
out into bag-shaped lakes near the coast), and where the bottom had not
been modified by secondary glaciation, that the receding tide displayed
a sea-bottom of till, covered with a thin stratum of loose stones and
shells. In some cases the till was so bare that it appeared like a
stiff mud deposited but yesterday.
At Bodö, an arctic coast station on the north side of the mouth of the
Salten fjord (lat. 67° 20´), where the packets make a long halt, is
a very characteristic example of this; a deposit of very tough till
forming an extensive plain just on the sea-level. The tide rises over
this, and the waves break upon it, forming a sort of beach by washing
away some of the finer material, and leaving the stones behind. The
ground being so nearly level, the reach of the tide is very great, and
thus a large area is exposed at low tide. Continuous with this, and
beyond the limit of high tide, is an extensive inland plain covered
with coarse grass and weeds growing directly upon the surface of the
original flat pavement of till.
There is no river at Bodö; the sea is clear, leaves no appreciable
deposit, and the degree of denudation of the clayey matrix of the till
is very much smaller than might be expected. The limit of high water
is plainly shown by a beach of shells and stones, but at low tide the
ground over which the sea has receded is a bare and scarcely modified
surface of till. I have observed the same at low water at many other
arctic stations. In the Tromsö Sund there are shallows at some distance
from the shore which are just covered with water at low tide. I landed
and waded on these, and found the bottom to consist of till covered
with a thin layer of shells, odd fragments of earthenware, and other
rubbish thrown overboard from vessels. It is evident that breakers of
considerable magnitude are necessary for the loosening of this tough
compact deposit—that it is very slightly, if at all, affected by the
mere flow of running water.
I specify these instances as characteristic and easy of verification,
as the packets all stop at these stations; but a yachtsman sailing at
leisure amidst the glorious coast scenery of the Arctic Ocean might
multiply such observations a hundredfold by stopping wherever such
strands are indicated in passing. I saw a multitude of these in places
where I was unable to go ashore and examine them.
A further question in this direction suggested itself on the spot,
viz., what is the nature of the “_banks_” which constitute the
fishing-grounds of Norway, Iceland, Newfoundland, etc. They are
submarine plains unquestionably—they must have a high degree of
fertility in order to supply food for the hundreds of millions of
voracious cod-fish, coal-fish, haddocks, hallibut, etc., that people
them. These large fishes all _feed on the bottom_, their chief food
being mollusca and crustacea, which must find, either directly or
indirectly, some pasture of vegetable origin. The banks are, in fact,
great meadows or feeding grounds for the lower animals which support
the higher.
From the Lofoten bank alone twenty millions of cod-fish are taken
annually, besides those devoured by the vast multitude of sea-birds.
Now this bank is situated precisely where, according to the
above-stated view of the origin of the till, there should be a huge
deposit. It occupies the Vest fjord, _i.e._, the opening between the
mainland and the Lofoden Islands, extending from Moskenes, to Lodingen
on Hindö, just where the culminating masses of the Kjolen Mountains
must have poured their greatest glaciers into the sea by a westward
course, and these glaciers must have been met by another stream pouring
from the north, formed by the glaciers of Hindö and Senjenö, and both
must have coalesced with a third flood pouring through the Ofoten
fjord, the Tys fjord, etc., from the mainland. The Vest fjord is about
sixty miles wide at its mouth, and narrows northward till it terminates
in the Ofoten fjord, which forks into several branches eastward. A
glance at a good map will show that here, according to my explanation
of the origin of the till, there should be the greatest of all the
submarine plains of till which the ancient Scandinavian glaciers have
produced, and of which the plains of till I saw on the coast at Bodö
(which lies just to the mouth of the Vest fjord, where the Salten fjord
flows into it), are but the slightly inclined continuation.
Some idea of this bank may be formed from the fact that outside of
the Lofodens the sea is 100 to 200 fathoms in depth, that it suddenly
shoals up to 16 or 20 fathoms on the east side of these rocks, and this
shallow plain extends across the whole 50 or 60 miles between these
islands and the mainland.[19] It must not be supposed the fjords or
inlets of Scandinavia are _usually_ shallower than the open sea; the
contrary is commonly the case, especially with the narrowest and those
which run farthest inland. They are _very much_ deeper than the open
sea.
If space permitted I could show that the great Storregen bank, opposite
Aalesund and Molde, where the Stor fjord, Mold fjord, etc., were the
former outlets of the glaciers from the highest of all the Scandinavian
mountains, and the several banks of Finmark, etc., from which, in the
aggregate, are taken another 20 or 30 millions of cod-fish annually,
are all situated just where theoretically they ought to be found. The
same is the case with the great bank of Newfoundland and the banks
around Iceland, which are annually visited by large numbers of French
fishermen from Dunkerque, Boulogne, and other ports.
Whenever the packet halted over these banks during our coasting trip we
demonstrated their fertility by casting a line or two over the bulwark.
No bait was required, merely a double hook with a flat shank attached
to a heavy leaden plummet. The line was sunk till the lead touched the
bottom, a few jerks were given, and then a tug was felt: the line was
hauled in with a cod-fish or hallibut hooked, not inside the mouth,
but externally by the gill-plates, the back, the tail, or otherwise.
The mere jerking of a hook near the bottom was sufficient to bring it
in contact with some of the population. There is a very prolific bank
lying between the North Cape and Nordkyn, where the Porsanger and Laxe
fjords unite their openings. Here we were able, with only three lines,
to cover the fore-deck of the packet with struggling victims in the
course of short halts of fifteen to thirty minutes. Not having any
sounding apparatus by which to fairly test the nature of the sea-bottom
in these places, I cannot offer any direct proof that it was composed
of till. By dropping the lead I could _feel_ it sufficiently to be
certain that it was not rock in any case, but a soft deposit, and
the marks upon the bottom of the lead, so far as they went, afforded
evidence in favor of its clayey character. A further investigation of
this would be very interesting.
But the most striking—I may say astounding—evidence of the fertility
of these banks, one which appeals most powerfully to the senses, is the
marvelous colony of sea-birds at Sverholtklubben, the headland between
the two last-named fjords. I dare not estimate the numbers that rose
from the rocks and darkened the sky when we blew the steam-whistle in
passing. I doubt whether there is any other spot in the world where an
equal amount of animal life is permanently concentrated. All these feed
on fish, and an examination of the map will show why—in accordance
with the above speculations—they should have chosen Sverholtklubben as
the best fishing-ground on the arctic face of Europe.
I am fully conscious of the main difficulty that stands in the way of
my explanation of the formation of the till, viz., that of finding
sufficient water to float the ice, and should have given it up had I
accepted Mr. Geikie’s estimate of the thickness of the great ice-sheet
of the great ice age.
He says (page 186) that “The ice which covered the low grounds of
Scotland during the early cold stages of the glacial epoch was
certainly more than 2000 feet in thickness, and it must have been even
deeper than this between the mainland and the Outer Hebrides. To cause
such a mass to float, the sea around Scotland would require to become
deeper than now by 1400 or 1500 feet at least.”
I am unable to understand by what means Mr. Geikie measured this depth
of the ice which covered these low grounds, except by assuming that its
surface was level with that of the upper ice-marks of the hills beyond.
The following passage on page 63 seems to indicate that he really has
measured it thus:—
“Now the scratches may be traced from the islands and the coast-line up
to an elevation of at least 3,500 feet; so that ice must have covered
the country to that height at least. In the Highlands the tide of ice
streamed out from the central elevations down all the main straths and
glens; and by measuring the height attained by the smoothed and rounded
rocks we are enabled to estimate roughly the probable thickness of the
old ice-sheet. But it can only be a rough estimate, for so long a time
has elapsed since the ice disappeared, the rain and frost together have
so split up and worn down the rocks of these highland mountains that
much of the smoothing and polishing has vanished. But although the
finer marks of the ice-chisel have thus frequently been obliterated,
yet the broader effects remain conspicuous enough. From an extensive
examination of these we gather that the ice could not have been less,
and was probably more than 3,000 feet thick in its deepest parts.”
Page 80 he says: “Bearing in mind the vast thickness reached by the
Scotch ice-sheet, it becomes very evident that the ice would flow
along the bottom of the sea with as much ease as it poured across the
land, and every island would be surmounted and crushed, and scored and
polished just as readily as the hills of the mainland were.”
Mr. Geikie describes the Scandinavian ice-sheet in similar terms, but
ascribes to it a still greater thickness. He says (page 404)—“The
whole country has been moulded and rubbed and polished by an immense
sheet of ice, which could hardly have been less than 6,000 or even
7,000 feet thick,” and he maintains that this spread over the sea and
coalesced with the ice-sheet of Scotland.
My recollection of the Lofoden Islands, which from their position
afford an excellent crucial test of this question, led me to believe
that their configuration presented a direct refutation of Mr. Geikie’s
remarkable inference; but a mere recollection of scenery being too
vague, a second visit was especially desirable in reference to this
point. The result of the special observations I made during this second
visit fully confirmed the impression derived from memory.
I found in the first place that all along the coast from Stavanger to
the Varanger fjord every rock _near the shore_ is glaciated; among the
thousands of low-lying ridges that peer above the water to various
heights none near the mainland are angular. The general character of
these is shown in the sketch of “My Sea Serpent,” in the last edition
of “Through Norway with a Knapsack.”
The rocks which constitute the extreme outlying limits of the Lofoden
group, and which are between 60 and 70 miles from the shore, although
mineralogically corresponding with those near the shore, are totally
different in their conformation, as the sketch of three characteristic
specimens plainly shows. Mr. Everest very aptly compares them to
shark’s teeth. Proceeding northward, these rocks gradually progress
in magnitude, until they become mountains of 3,000 to 4,000 feet in
height; their outspread bases form large islands, and the Vest fjord
gradually narrows.
The remarkably angular and jagged character of these rocks when
weathered in the air renders it very easy to trace the limits of
glaciation on viewing them at a distance. The outermost and smallest
rocks show from a distance no signs of glaciation. If submerged, the
ice of the great ice age was then enough to float over without touching
them; if they stood above the sea, as at present, they suffered no
more glaciation than would be produced by such an ice-sheet as that of
the “paleocrystic” ice recently found by Captain Nares on the north
of Greenland. Progressing northward, the glaciation begins to become
visible, running up to about 100 feet above the sea-level on the
islands lying westward and southward of Ost Vaagen. Further northward
along the coast of Ost Vaagen and Hindö, the level gradually rises to
about 500 feet on the northern portion of Ost Vaagen, and up to more
than 1,000 feet on Hindö, while on the mainland it reaches 3,000 to
4,000 feet.
A remarkable case of such variation, or descent of ice-level, as the
ice-sheet proceeded seaward, is shown at Tromsö. This small oblong
island (lat. 69° 40´), on which is the capital town of Finmark, lies
between the mainland and the large mountainous island of Kvalö, with
a long sea-channel on each side, the Tromösund and the Sandesund; the
total width of these two channels and the island itself being about
four or five miles. The general line of glaciation from the mainland
crosses the broad side of these channels and the island, which has
evidently been buried and ground down to its present moderate height of
two or three hundred feet. Both of the channels are till-paved. On the
east or inland side the mountains near the coast are glaciated to their
summits—are simply _roches moutonnées_, over which the reindeer of
the Tromsdal Lapps range and feed. On the west the mountains are dark,
pyramidal, non-glaciated peaks, with long vertical snow-streaks marking
their angular masses.
The contrast is very striking when seen from the highest part of
the island, and is clearly due to a decline in the thickness of the
ice-sheet in the course of its journey across this narrow channel.
Speaking roughly from my estimation, I should say that this thinning
or lowering of the limits of glaciation exceeds 500 feet between the
opposite sides of the channel, which, allowing for the hill slopes,
is a distance of about 6 miles. This very small inclination would
bring a glacier of 3,000 feet in thickness on the shore down to the
sea-level in an outward course of 30 miles, or about half the distance
between the mainland and the outer rocks of the Lofodens shown in the
engraving.
I am quite at a loss to understand the reasoning upon which Mr. Geikie
bases his firm conviction respecting the depth of the ice-sheet on the
low grounds of Scotland and Scandinavia. He seems to assume that the
glaciers of the great ice age had little or no superficial down slope
corresponding to the inclination of the base on which they rested. I
have considerable hesitation in attributing this assumption to Mr.
Geikie, and would rather suppose that I have misunderstood him, as
it is a conclusion so completely refuted by all we know of glacier
phenomena and the physical laws concerned in their production; but the
passages I have quoted, and several others, are explicit and decided.
Those geologists who contend for the former existence of a great polar
ice-cap radiating outwards and spreading into the temperate zones,
might adopt this mode of measuring its thickness, but Mr. Geikie
rejects this hypothesis, and shows by his map of “The Principal Lines
of Glacial Erosion in Sweden, Norway, and Finland,” that the glaciation
of the extreme north of Europe proceeded from south to north; that the
ice was formed on land, and proceeded seawards in all directions.
I may add to this testimony that presented by the North Cape, Sverholt,
Nordkyn, and the rest of the magnificent precipitous headlands that
constitute the characteristic feature of the arctic-face of Europe.
They stand forth defiantly as a phalanx of giant heralds proclaiming
aloud the fallacy of this idea of southward glacial radiation; and
in concurrence with the structure and striation of the great glacier
troughs that lie between them, and the planed table-land at their
summits, they establish the fact that during the greatest glaciation of
the glacial epoch the ice-streams were formed on land and flowed out
to sea, just as they now do at Greenland, or other parts of the world
where the snow line touches or nearly approaches the level of the sea.
All such streams must have followed the slope of the hill-sides upon
which they rested and down which they flowed, and thus the upper limits
of glaciation afford no measure whatever of the thickness of the ice
upon “the low grounds of Scotland,” or of any other glaciated country.
As an example, I may refer to Mont Blanc. In climbing this mountain
the journey from the lower ice-wall of the Glacier de Bessons up to
the _bergschrund_ above the _Grand Plateau_ is over one continuous
ice-field, the level of the upper part of which is more than 10,000
feet above its terminal ice-wall. Thus, if we take the height of the
striations or smoothings of the upper _nevé_ above the low grounds on
which the ice-sheet rests, and adopt Mr. Geikie’s reasoning, the lower
ice-wall of the Glacier de Bessons should be 10,000 feet thick. Its
actual thickness, as nearly as I can remember, is about 10 or 12 feet.
Every other known glacier presents the same testimony. The drawing of a
Greenland glacier opposite page 47 of Mr. Geikie’s book shows the same
under arctic conditions, and where the ice-wall terminates in the sea.
I have not visited the Hebrides, but the curious analogy of their
position to that of the Lofodens suggests the desirability of similar
observations to those I have made in the latter. If the ice between
the mainland and the Outer Hebrides was, as Mr. Geikie maintains,
“certainly more than 2000 feet in thickness,” and this stretched
across to Ireland, besides uniting with the still thicker ice-sheet
of Scandinavia, these islands should all be glaciated, especially the
smaller rocks. If I am right, the smaller outlying islands, those south
of Barra, should, like the corresponding rocks of the Lofodens, display
no evidence of having been overswept by a deep “_mer de glace_.”
I admit the probability of an ice-sheet extending as Mr. Geikie
describes, but maintain that it thinned out rapidly seaward, and
there became a mere ice-floe, such as now impedes the navigation of
Smith’s Sound and other portions of the Arctic Ocean. The Orkneys and
Shetlands, with which I am also unacquainted, must afford similar
crucial instances, always taking into account the fact that the larger
islands may have been independently glaciated by the accumulations
due to their own glacial resources. It is the small rocks standing at
considerable distance from the shores of larger masses of land that
supply the required test-conditions.
From the above it will be seen that I agree with Mr. Geikie in
regarding the till as a “_moraine profonde_,” but differ as to the
mode and place of its deposition. He argues that it was formed under
glaciers of the thickness he describes, while their whole weight rested
upon it.
This appears to me to be physically impossible. If such glaciers are
capable of eroding solid rocks, the slimy mud of their own deposits
could not possibly have resisted them. The only case where this might
have happened is where a mountain-wall has blocked the further downward
progress of a glacier, or in pockets, or steep hollows which a glacier
might have bridged over and filled up; but such pockets are by no means
the characteristic localities of till, though the till of Switzerland
may possibly show examples of the first case. The great depth of the
inland lakes of Norway, their bottoms being usually far below that of
the present sea-bottom, is in direct contradiction of this.[20] They
should, before all places, be filled with till, if the till were a
ground moraine formed on land; but all we know of them confirms the
belief that the glaciers deepened them by erosion instead of shallowing
them by deposition.
Mr. Geikie’s able defence of Ramsay’s theory of lake-basin erosion
is curiously inconsistent with his arguments in favor of the ground
moraine.
I fully concur with Mr. Geikie’s arguments against the iceberg theory
of the formation of the till. This, I think, he has completely refuted.
Before concluding I must say a few words on those curious lenticular
beds of sand and gravel in the till which appear so very puzzling. A
simple explanation is suggested in connection with the above-sketched
view of the formation of the till. All glaciers, whether in arctic or
temperate climates, are washed by streamlets during summer, and these
commonly terminate in the form of a stream or cascade pouring down
a “_moulin_”—a well bored by themselves and reaching the bottom of
the glacier. Now what must be the action of such a downflow of water
upon my supposed submarine bed of till just grazing the bottom of the
glacier? Obviously, to wash away the fine clayey particles, and leave
behind the coarser sand or gravel. It must form just such a basin or
lenticular cavity as Mr. Geikie describes. The oblong shape of these,
their longer axis coinciding with the general course of the glacier,
would be produced by the onward progress of the moulin. The accordance
of their other features with this explanation will be seen on reading
Mr. Geikie’s description (pp. 18, 19, etc).
The general absence of marine animals and their occasional exceptional
occurrence in the intercalated beds is just what might be expected
under the conditions I have sketched. In the gloomy subglacial depths
of the sea, drenched with continual supplies of fresh water and cooled
below the freezing-point by the action of salt water on the ice,
ordinary marine life would be impossible; while, on the other hand, any
recession of the glacial limit would restore the conditions of arctic
animal life, to be again obliterated with the renewed outward growth of
the floating skirts of the inland ice-mantle.
But I must now refrain from the further discussion of these and other
collateral details, but hope to return to them in another paper.
In “Through Norway with Ladies” I have touched lightly upon some
of these, and have more particularly described some curious and
very extensive evidences of secondary glaciation that quite escaped
my attention on my first visit, and which, too, have been equally
overlooked by other observers. In the above I have endeavored to keep
as nearly as possible to the main subject of the origin of the till and
the character of the ancient ice-sheet.
THE BAROMETER AND THE WEATHER.
The barometer was invented by Torricelli, an Italian philosopher of
the seventeenth century. It consists essentially of a long tube open
at one end and closed at the other, and partly filled with mercury;
but instead of being filled like ordinary vessels, with the open
end or mouth upwards and the closed end or bottom downwards, the
barometer-tube is inverted, and has its open mouth downwards. This open
mouth is either dipped into a little cup of mercury or bent a little
upwards.
Why does not the mercury run out of this lower open end and overflow
the little cup when it is inverted after being filled?
The answer to this question includes the whole mystery and principle
of the barometer. The mercury does not fall down because something
pushes it up and supports it with a certain degree of pressure, and
that something is the atmosphere which extends all round the world,
and presses downwards and sideways and upwards—in every direction, in
fact—with a force equal to its weight, _i.e._, with a pressure equal
to about 15 lbs. on every square inch. A column or perpendicular square
stick of air one inch thick each way, and extending from the surface
of the sea up to the top of the atmosphere, weighs about 15 lbs.;
other columns or sticks next to it on all sides weigh the same, and so
on with every portion; and all these are for ever squeezing down and
against each other, and, being fluid, transmit their pressure in every
direction, and against the earth and everything upon it, and therefore
upon the mercury of the barometer-tube.
We have supposed the air to be made up of columns or sticks of air one
inch each way, but might have taken any other size, and the weight
and pressure would be proportionate. Now mercury, bulk for bulk, is
so much heavier than air, that a stick or column of this liquid metal
about 30 inches high weighs as much as a stick or column of air of
same thickness reaching from the surface of the earth to the top of
the atmosphere; therefore, the 30-inch stick of mercury balances the
pressure of the many miles of atmosphere, and is supported by it. Thus
the column of mercury may be used to counterbalance the atmosphere and
show us its weight; and such a column of mercury is a barometer, or
“weight measure.” The word _barometer_ is compounded of the two Greek
words—_baros_, weight, and _metron_, a measure.
If you take a glass tube a yard long, stopped at one end and open at
the other, fill it with mercury, stop the open end with your thumb,
then invert the tube and just dip the open end in a little cup of
mercury, some of the mercury in the tube will fall into the cup, but
not all; only six inches will fall, the other 30 inches will remain,
with an empty space between it and the stopped end of the tube. When
you have done this you will have made a rude barometer. If you prop up
the tube, and watch it carefully from day to day, you will find that
the height of the column of mercury will continually vary. If you live
at the sea-level, or thereabouts, it will sometimes rise more than 30
inches above the level of the mercury in the cup, and frequently fall
below that height. If you live on the top of a high mountain, or on any
high ground, it will never reach 30 inches, will still be variable, its
average height less than if you lived on lower ground; and the higher
you go the less will be this average height of the mercury.
The reason of this is easily understood. When we ascend a mountain
we leave some portion of the atmosphere below us, and of course less
remains above; this smaller quantity must have less weight and press
the mercury less forcibly. If the barometer tells the truth, it must
show this difference; and it does so with such accuracy that by means
of a barometer, or rather of two barometers—one at the foot of the
mountain and one at its summit—we may, by their difference, measure
the height of the mountain provided we know the rules for making the
requisite calculations.
The old-fashioned barometer, with a large dial-face and hands like a
clock, is called the “wheel barometer,” because the mercury, in rising
and falling, moves a little glass float resting upon the mercury of
the open bent end of the tube; to this float and its counterpoise a
fine cord is attached; and this cord goes round a little grooved wheel
to which the hands are attached. Thus the rising and falling of the
mercury moves the float, the float-cord turns the wheel, and the wheel
moves the hand that points to the words and figures on the dial. When
this hand moves towards the right, or in the direction of an advancing
clock-hand, the barometer is rising; when it goes backwards, or
opposite to the clock-hand movement, the mercury is falling. By opening
the little door at the back of such a barometer, the above-described
mechanism is seen. In doing this, or otherwise moving your barometer,
be careful always to keep it upright.
It sometimes happens to these wheel barometers that they, suddenly
cease to act; and in most cases the owner of the barometer may save the
trouble and expense of sending it to the optician by observing whether
the cord has slipped from the little wheel, and if so, simply replacing
it in the groove upon its edge. If, however, the mischief is caused by
the tube being broken, which is seen at once by the mercury having run
out, the case is serious, and demands professional aid.
The upright barometer, which shows the surface of the mercury itself,
is the most accurate instrument, provided it is carefully read. This
form of instrument is always used in meteorological observatories,
where minute corrections are made for the expansion and contraction
which variations of temperature produce upon the length of the mercury
without altering its weight, and for the small fluctuations in the
level of the mercury cistern. With such instruments, fitted with an
apparatus called a “vernier” the height of the mercury may be read to
hundredths of an inch.
The necessity for the 30 inches of mercury renders the mercurial
barometer a rather cumbrous instrument: it must be more than 30 inches
long, and is liable to derangement from the spilling of the mercury.
On this account portable barometers of totally different construction
have been invented. The “aneroid” barometer is one of these—the only
one that is practically used to any extent. It contains a metal box
partly filled with air; one face of the box is corrugated, and so thin
that it can rise and fall like a stretched covering of india-rubber.
As the pressure of the outside air varies it does rise and fall,
and by a beautifully-delicate apparatus this rising and falling is
magnified and represented upon the dial. Such barometers are made small
enough to be carried in the pocket, and are very useful for measuring
the heights of mountains; but they are not quite so accurate as the
mercurial barometer, and are therefore not used for rigidly scientific
measurements; but for all ordinary purposes they are accurate enough,
provided they are occasionally compared with a standard mercurial
barometer, and adjusted by means of a watch-key axis provided for that
purpose, and seen on the back of the instrument. They are sufficiently
delicate to tell the traveller in a railway whether he is ascending
or descending an incline, and will indicate the difference of height
between the upper and lower rooms of a three-story house. With due
allowance for variations of level, the traveler may use them as weather
indicators; especially as it is the direction in which the barometer
is moving (whether rising or falling) rather than its absolute height
that indicates changes of weather. Thus by placing the aneroid in his
room on reaching his hotel at night, carefully marking its height then
and there, and comparing this with another observation made on the
following morning, he may use it as a weather-glass in spite of hill
and dale.
Water barometers have been made on the same principle as the mercury
barometer; but as water is 13½ times lighter, bulk for bulk, than
mercury, the height of the column must be 13½ times 30 inches, or,
allowing for variations, not less than 34 feet. This, of course,
is very cumbrous; the evaporation of the water presents another
considerable difficulty,[21] still such a barometer is a very
interesting instrument, as it shows the atmospheric fluctuations on
13½ times the scale of the ordinary barometer. A range of about five
feet is thus obtained; and not only the great waves, but even the
comparatively small ripples of the atmospheric ocean are displayed by
it. In stormy weather it may be seen to rise and fall and pulsate like
a living creature, so sensitively does it respond to every atmospheric
fluctuation.
But why should the height of the barometer vary while it remains in the
same place?
If the quantity of air surrounding the earth remains the same, and if
the barometer measures its weight correctly, why should the barometer
vary?
Does the atmosphere grow bigger and smaller, lighter and heavier, from
time to time?
These are fair questions, and they bring us at once to some of the
chief uses of the barometer. The atmosphere is a great gaseous ocean
surrounding the earth, and we are creeping about on the bottom of this
ocean. It has its tides and billows and whirling eddies, but all these
are vastly greater than those of the watery ocean. At one time we are
under the crest or rounded portion of a mighty atmospheric wave, at
another the hollow between two such waves is over our heads, and thus
the depth of atmosphere, or quantity of air, above us is variable.
This variation is the combined result of many co-operating causes. In
the first place, there are great atmospheric tides, caused, like those
of the sea, by the attraction of the sun and moon; but these do not
_directly_ affect the barometer, because the attracting body supports
whatever it lifts. Variations of temperature also produce important
fluctuations in the height and density of the atmosphere, some of which
are indicated by the barometer—others are not. Thus a mere expansion
or contraction of _dry_ air, increasing the depth or the density of the
atmospheric ocean, would not affect the barometer, as mere expansion
and contraction only alter the _bulk_ without affecting the _weight_ of
the air. But our atmosphere consists not only of the permanent gases,
nitrogen and oxygen; it contains besides these and carbonic acid, a
considerable quantity of gaseous matter, which is not permanent, but
which may be a gas at one moment—contributing its whole weight to
that of the general atmosphere—and at another moment some of it may
be condensed into liquid particles that fall through it more or less
rapidly, and thus contribute nothing to its weight.
What, then, is this variable constituent that sometimes adds to the
weight of the atmosphere and the consequent height of the barometer,
and at others may suddenly cease to afford its full contribution to
atmospheric pressure?
It is simply water, which, as we all know, exists as solid, liquid, or
gas, according to the temperature and pressure to which it is exposed.
We all know that steam when it first issues from the spout of a
tea-kettle is a transparent gas, or true vapor, but that presently, by
contact with the cool air, it becomes white, cloudy matter, or minute
particles of water; and that, if these are still further cooled, they
will become hoar-frost or snow, or solid ice. Artificial hoar-frost and
snow may be formed by throwing a jet of steam into very cold, frosty
air. If you take a tin canister or other metal vessel, fill it with a
mixture of salt with pounded ice or snow, and then hold the outside of
the canister against a jet of steam, such as issues from the spout of a
tea-kettle, a snowy deposit of hoar-frost will coat the outside of the
tin. Now let us consider what takes place when a warm south-westerly
wind, that has swept over the tropical regions of the Atlantic ocean,
reaches the comparatively cold shores of Britain. It is cooled thereby,
and some of its gaseous water is condensed—forming mists, clouds,
rain, hoar-frost or snow. The greater part of this forms and falls on
the western coasts, on Cornwall, Ireland, the Western Highlands of
Scotland. Ireland gets the lion’s share of this humidity, and hence her
“emerald” verdure. The western slope of a mountain, in like manner,
receives more rain than the side facing the east.
How does this condensation affect the barometer?
It must evidently cause it to fall, inasmuch as the air must be
lightened to the exact extent of all that is taken out of it and
precipitated. But the precipitation is not completed immediately the
condensation occurs. It takes some time for the minute cloudy particles
to gather into rain drops and fall to the earth, while the effect of
the condensation upon the barometer is instantaneous; the air begins
to grow lighter immediately the gas is converted into cloud or mist,
and the barometer falls just at the same time and same rate as this is
produced; but the rain comes some time afterwards. Hence the use of the
barometer as a “weather glass.” When intelligently and properly used it
is very valuable in this capacity; but, like most things, it may easily
be misunderstood and misused.
The most common error in the use of the barometer is that to which
people are naturally led by the words engraved upon it, “Stormy, Much
Rain, Rain, Change, Fair, Set Fair,” etc. A direct and absolute blunder
or falsehood is usually short-lived, and deceives but few people;
but a false statement, with a certain amount of superficial truth,
may survive for ages, and deceive whole generations. Now this latter
is just the character of the weather signs that are engraved on our
popular barometers; they are unsound and deceptive, but not utterly
baseless.
_Stormy_, _Much Rain_, and _Rain_ are marked against the low readings
of the barometer, and _Very Dry_, _Set Fair_, and _Fair_ against the
higher readings. A low barometer is not a reliable sign of wet or
stormy weather, neither is a high barometer to be depended upon for
expecting fine weather; and yet it is true that we are more likely to
have fine weather with a high than with a low barometer, and also the
liability to rain and storms is greater with a low than with a high
barometer.
The best indications of the weather are those derived from the
direction in which the barometer is moving—whether rising or
falling—rather than its mere absolute height.
A sudden and considerable fall is an almost certain indication of
strong winds and stormy weather. This is the most reliable of the
prophetic warnings of the barometer, and the most useful, inasmuch as
it affords the mariner just the warning he requires when lying off a
dangerous coast, or otherwise in peril by a coming gale. Many a good
ship has been saved by intelligent attention to the barometer, and by
running into haven, or away from a rocky shore when the barometer has
fallen with unusual rapidity.
The next in order of reliability is the indication afforded by a
steady and continuous fall after a long period of fine weather. This is
usually followed by a decided change of weather, and the greater the
fall the more violent the change. If the fall is slow, and continues
steadily for a long time, the change is likely to be less sudden but
more permanent, _i.e._, the rain will probably arrive after some time,
and then continue steadily for a long period.
In like manner, a steady, regular rise, going on for some days in the
midst of wet weather, may be regarded as a hopeful indication of coming
continuous fine weather—the more gradual and steady the rise, the
longer is the fine weather likely to last.
The least reliable of all the barometric changes is a sudden rise. In
winter it may be followed by hard and sudden frost, in summer by sultry
weather and thunder-storms. All that may be safely said of such sudden
rise is, that it indicates a change of some sort.
The barometer is usually high with N.E. winds, and low with S.W. winds.
The preceding explanations show the reason of this. In a given place
the extreme range of variation is from 2 to 2½ inches.
It has been proposed that the following rules should be engraved on
barometer-plates instead of the usual words:—
1st. Generally, the rising of the mercury indicates the approach of
fair weather; the falling of it shows the approach of foul weather.
2d. In sultry weather, the fall of the barometer indicates coming
thunder. In winter, the rise of the mercury indicates frost. In frost,
its fall indicates thaw, and its rise indicates snow.
3d. Whatever change in the weather suddenly follows a change in the
barometer, may be expected to last but a short time.
4th. If fair weather continues for several days, during which the
mercury continually falls, a long succession of foul weather will
probably ensue; and again, if foul weather continues for several days,
while the mercury continually rises, a long succession of fair weather
will probably follow.
5th. A fluctuating and unsettled state of the mercurial column
indicates changeable weather.
As the barometer is subject to slight diurnal variations, irrespective
of those atmospheric changes which affect the weather, it is desirable
in making comparative observations to do so at fixed hours of the day.
Nine or ten in the morning and same hour in the evening are good times
for observations that are to be recorded. These are about the hours of
daily maxima or highest readings due to regular diurnal variation.
The true reading of the barometer is the height at which it would stand
if placed at the level of the sea at high tide; but, as barometers are
always placed more or less above this level, a correction for elevation
is necessary. When the height of the place is known this correction may
be made by adding one tenth of an inch to the actual reading for every
85 feet of elevation up to 510 feet; the same for every 90 feet between
510 and 1140 feet, for every 95 feet between 1140 and 1900 feet, and
for every 100 feet above this and within our mountain limits. This
simple and easy rule is sufficiently accurate for practical purposes.
Thus, a barometer on Bray Head, or any place 800 feet above the sea,
would require a correction of six-tenths for the first 510 feet, and
a little more than three-tenths more for the remaining 290 feet.
Therefore, if such a barometer registered the pressure at 29-1/10, the
proper sea-level reading would be a little above 30 inches.
The most important prognostications of the barometer are those afforded
by what is called the “barometric gradient or incline,” showing the
up-hill and down-hill direction of the atmospheric inequalities; but
this can only be ascertained by comparing the state of the barometer
at different stations at the same time. Thus, if the barometer is
one-fourth of an inch higher at Dublin than at Galway, and the
intermediate stations show intermediate heights, there must be an
atmospheric down-hill gradient from Dublin to Galway; Dublin must
be under the upper and Galway under the lower portion of a great
atmospheric wave or current. It is evident that when there is thus
more air over Dublin than over Galway, there must follow (if nothing
else interferes) a flow of air from Dublin towards Galway. It is also
evident that, in order to tell what else may interfere, we must know
the atmospheric gradients beyond and around both Dublin and Galway, and
for considerable distances.
We are now beginning to obtain such information by organizing
meteorological stations and observatories, and transmitting the results
of simultaneous observations by means of the electric telegraph to
certain head-quarters.
The subject is occupying much attention, and the managers of those
splendid monuments of British energy—our daily newspapers—are
publishing daily weather charts, and therefore a few simple
explanations of the origin, nature, and significance of such charts
will doubtless be appreciated by our readers.
The grand modern improvement of the barometer, the thermometer,
the anemometer, the pluviometer, etc., is that of making them
“self-registering.” We are told that Cadmus invented the art of
writing, and we honor his memory accordingly. But he ventured no
further than teaching human beings to write. Modern meteorologists
have gone much further; they have taught the winds and the rains and
the subtle heavings of the invisible air to keep their own diaries,
to write their own histories on paper that is laid before them, with
pencils that are placed in their fleshless, boneless, and shapeless
fingers. This achievement is wrought by comparatively simple means. The
paper is wound upon an upright drum or cylinder, and this cylinder is
made to revolve by clock-work, in such a manner that a certain breadth
travels on during the twenty-four hours. This breadth of paper is
divided by vertical lines into twenty-four parts, each of which passes
onward in one hour. Connected with the barometer is a pencil which,
by means of a spring, presses lightly upon the revolving sheet, and
this pencil, while thus pressing, rises and falls with the mercury.
It is obvious that, in this manner, a line will be drawn as the paper
moves. If the mercury is stationary, the line will be horizontal—only
indicating the movement of the drum; if the mercury falls, the line
will slope downwards; if it rises, it will incline upwards. By ruling
horizontal lines upon the paper, representing inches, tenths, and
smaller fractions, if desired, the whole history of the barometrical
movements will be graphically recorded by the waving or zigzag lines
thus drawn by the atmosphere itself.
The subjoined copy of the _Daily Telegraph_ Barometer Chart represents,
on a small scale, a four days’ history of barometrical movements:
The large figures at the side (29 and 30) represent inches; the smaller
figures tenths of inches.
[Illustration]
The pressure of the wind is similarly pictured by means of a large vane
which turns with the wind, and to the windward face of which a flat
board or plate of metal, one foot square, is attached perpendicularly.
As the wind strikes this it presses against it with a force
corresponding to a certain number of pounds, ounces, and fractions of
an ounce. A spring like that of an ordinary spring letter-balance is
compressed in proportion to this pressure. This movement of the spring
is transmitted mechanically to another pencil like the above described,
working against the same drum; thus another history is written on the
same paper—the horizontal lines now representing fractions of pounds
of pressure, instead of fractions of inches of mercury.
It has been found that if a semi-globular cup of thin metal is exposed
to the wind, the pressure upon the round or convex side of the
hemisphere is equal to two thirds of that upon the hollow or concave
side. By placing four such cups upon cross-arms, and the arms on a
pivot, the wind, from whatever quarter it may come, will always blow
them round with their convex faces foremost; and they will move with
one third of the actual velocity of the wind. By a simple clock-work
arrangement, these arms move another pencil, in such a manner that it
strikes the paper hammer-fashion every time the wind has completed a
journey of one mile, or other given distance; and thus a series of dots
upon the revolving paper records the velocity of the wind according
to their distances apart. As the pressure of the wind is governed by
two factors, viz., the density and velocity of the moving air, the
relations between the barometer curve, the pressure curve, and the
velocity dots, are very interesting.
The direction of the wind is written by a pencil fixed to a quick
worm—a screw-thread upon the axis of the vane. As the vane turns
round—N., E., S., or W.—it screws the pencil up or down, and thus the
horizontal lines first described as registering tenths of inches of
barometric pressure do duty as showing the points of the compass from
which the wind is blowing; and, by reference to the zigzag line drawn
by this pencil of the wind, its direction at any particular time of day
may be ascertained as certified by its own sign-manual.
The wind-gauge is called an anemometer. Connected with this is the
pluviometer, or rain-gauge—an upright vessel with an open mouth of
measured area—say 100 square inches. This receives the rain that
falls. By means of a pipe the water is conveyed to a vessel having a
surface of—say one square inch. By this arrangement, when sufficient
rain has fallen to cover the surface of the earth to the depth of one
hundredth of an inch, the little vessel below will contain water one
inch in depth. By balancing this vessel at the end of a long arm, it
is made to preponderate gradually as the weight of water it receives
increases, and finally, when filled, it tips over altogether, empties
itself, and then rises to its starting place in equilibrium. To the
other end of this arm a pencil is attached, which inscribes all these
movements on the revolving paper, and thus tells the history of the
rainfall. The line is zigzag while the rain is falling, and horizontal
while the weather is fair. The amount of inclination of the zigzag
line measures the depth of rain by means of the same ruled lines on
the paper as measure the height of the barometer, etc. Every time
the measuring vessel tips over a perpendicular line is drawn, and
the pencil resumes its starting level. The papers containing these
autographs of the elements may, of course, be kept as permanent records
for reference whenever needed, or the results may be tabulated in other
forms.
There are many modifications in the details of these self-registering
instruments. In some of them photography is made to do a part of the
work. The above description indicates the main principles of their
construction, without attempting to enter upon minute details.
Meteorological observatories are provided with these instruments, and
all nations worthy of the name of civilized co-operate with more or
less efficiency in providing and endowing such establishments. They
are placed in suitable localities, and communicate with each other,
and with certain head-quarters, by means of the electric telegraph.
One of these head-quarters is the Meteorological Office, at No. 116
Victoria Street, Westminster, S.W., which daily receives the results of
the observations taken at about fifty stations on the British Islands
and the Continent. The chief observations are made simultaneously—at
8 A.M.—and telegraphed in cypher to London, where they usually
arrive before 10 A.M. As they come in they are marked down in their
proper places upon a large chart, and when this chart is sufficiently
completed, a condensed or abstract copy is made containing as much
information as may be included in the small newspaper charts. This is
copied mechanically on a reduced scale on a slab on which the outline
chart has been already engraved. This engraving completed, casts are
made in fusible metal with the black lines in relief, for printing with
ordinary type, and the casts are set up with the ordinary newspaper
types, and printed with the letterpress matter.
The engravings overleaf are taken from two of the newspaper weather
charts for the dates of October 5th and 6th. They are enlarged and
printed more clearly than the originals, with an explanation of signs
at foot of the charts.
It will be observed that, in the chart for October 5th, an isobar of
29.2 runs up in a N.E. direction from between the Orkney and Shetland
islands, crosses the North Sea, strikes the coast of Norway near
Bergen, and then proceeds onwards towards Throndhjem. An isobar of 29.5
crosses Scotland, following very nearly the line of the Grampians,
enters the North Sea about Aberdeen, and crosses to Christiansund; then
runs up the Skager Rack and Christiania Fjord towards Christiania.
Another isobar of 29.8 crosses Ireland through Connaught to Dublin,
onward across England by Liverpool and the Humber, over the North Sea,
and through Sleswig to the Baltic. These three are nearly parallel;
but now we find another isobar—that of 30.2—taking quite a different
course, by starting from the Bay of Biscay about Nantes; running on
towards Paris and Strasbourg, and then bending sharp round, as though
frightened by the Germans, and retreating to the Gulf of Lyons by an
opposite course to that on which it started. On the following day all
has changed; the northern isobars are running down south-eastwards
instead of north-east, and are remarkably parallel. In the left-hand
upper corner of this chart is a note that “_our west, north, and
eastern coasts were warned yesterday_.” Why was this? It was mainly
because the barometric _gradient_ or incline was so steep. On the 5th
there was one inch of difference between the Orkneys and the Bay of
Biscay, or between Bergen and Paris, while the barometer was still
falling in Norway and at the same moment rising in Ireland and France.
On the following day these movements culminated in a gradient of
1.4—nearly one and a half inches—between Cornwall and the ancient
capital of Norway.
[Illustration: WEATHER CHART, OCTOBER 5, 1875.]
[Illustration: WEATHER CHART, OCTOBER 6, 1875.]
EXPLANATION OF WEATHER CHART.
In these charts the state of the sea—whether “rough,”
“smooth,” “moderate,” “slight,” etc., is marked in capital
letters; and the state of the weather—as “clear,” “dull,”
“cloudy,” “showery,” etc., in small letters. The direction of
the wind is indicated by the arrows. Unlike the arrows of a
vane, these do not point towards the direction from which the
wind is coming, but are _flying_ arrows represented as moving
_with_ the wind, and consequently pointing to _where the wind
is going_. The force of the wind is represented in five degrees
of strength. 1st. A _calm_, by a horizontal line and zero—0
thus 0; 2nd. A _light wind_, by an arrow with one barb and no
feathers ______\; 3rd. A _fresh to strong breeze_, by an arrow
with two barbs and no feathers ——————>; 4th. A _gale_, by an
arrow with two feathers >——————>; and 5th. A _violent gale_, by
an arrow with four feathers >>——————>. The temperature—in the
shade—is marked in figures with a small circle to the right,
indicating degrees—as 60°. These figures stand in the places
where the observations are made. The other figures—usually
with decimals, and placed at the end of the dotted lines—give
the height of the barometer—the dotted line showing where
this particular height remained the same at the time of
observation. These dotted lines are called “isobars,” or _equal
weights_—the weight or over-head pressure of the atmosphere
being the same all along the line.
What must follow from this condition of the atmosphere? Clearly a great
flow or rush of air from the south towards the comparatively vacuous
regions of the north. The gases of our atmosphere, like the waters of
the ocean, are always struggling to find their level, and thereby the
winds are produced. The air flows from all sides towards the lowest
isobar. But what, then, must be the course of the wind? Will it be
in straight lines towards this point? If so, a strange conflict must
result when all these currents meet from opposite directions. What
will follow from this conflict? A skillful physicist can work out this
problem mathematically, but we are not all mathematicians, some of us
are not able to follow his formulæ, and, therefore, will do better
by resorting to simple observation of other analogous and familiar
phenomena. A funnel or any vessel with a hole in the bottom will answer
our purpose. Let us fill such a vessel with water, then open the hole,
and see what will be the course of the water when it is struggling to
flow from all sides to the one point of vacuity. It will very soon
establish a vortex or whirlpool, _i.e._, the water instead of flowing
directly by straight lines from the sides to the centre of the funnel,
will take a roundabout, spiral course, and thus screw its way down the
outlet of the funnel.
This is just what occurs when the air is rushing to fill a
comparatively vacuous atmospheric space. It moves in a spiral; and
in the Northern Hemisphere this spiral always turns in the same way,
viz., in the opposite direction to the hands of a clock when flowing
inwards, and _vice versâ_, or _with_ the clock hands, when the air is
overflowing from a centre of high pressure.
In the chart for October 5th both these cases are illustrated. North of
Dublin there is a curvature of isobars and an inrush of winds towards
a northward low pressure, or vacuous region; while south of Dublin the
isobar tends sharply round a high-pressure focus, and the overflowing
wind is correspondingly reversed in direction, as shown by the arrows.
The next chart, for October 6th, shows that the overflow has spread
northwards as far as Dublin, and the high-pressure focus has also
moved northwards. It follows from this that if you know the barometric
gradient, and stand with your left hand to the region of low barometer
and your right hand to that of the high barometer, the wind will
blow against your back, _i.e._, you will face the direction of the
wind, or of those flying arrows on the chart. This interesting and
important generalization is called “Buys Ballot’s Law.” In spite of the
proverbial fickleness of the winds this simple law is rarely infringed,
though it may require a slight modification of statement—inasmuch
as the wind does not move in _circles_ round the vacuous space, but
in spirals, and thus it blows not quite square to the back, but
rather obliquely, or a little on the right side. This is shown by the
arrows in the charts, and is most strikingly displayed in the chart
for October 6th, between the isobars of 30.3 and 30.5. To take, in
Ireland, the position required by Buys Ballot’s Law, one must have
stood facing the east, and accordingly, the westerly wind would then
blow upon one’s back. In Paris, at the same moment, the position would
be facing south-east, and the wind was curving round accordingly.
Further south—at Bordeaux or the Pyrenees—the position becomes almost
reversed, _i.e._, facing south-west, and the wind is reversed in equal
degree.
Here, then, on these days we had the chief conditions of wind and rain,
a steep and increasing barometric gradient, and a flow over our islands
of humid air from the south and west regions of the great Atlantic.
Strong winds and heavy rains did follow accordingly; and the prophetic
warnings of the Meteorological Office, which are conveyed by means of
signals displayed on prominent parts of the coast, were fulfilled.
Mr. Scott, the Director of the Meteorological Office, tells us that
“The degree of success that has attended our warnings in these islands,
on the average of the last two years, has been that over 45 per cent
have been followed by severe gales; and over 33 per cent in addition
have been followed by wind too strong for fishing-boats and yachts,
though in themselves not severe gales; this gives a total percentage of
success of nearly 80.”
In winter the movements of the air are more decided, and the changes
are often so rapid that the warning sometimes comes too late. With
increased means—_i.e._, more money to cover additional work, and more
stations—better results might be obtained. The United States expend
50,000_l._ a year in weather telegraphy, exclusive of salaries, while
the United Kingdom only devotes 3,000_l._ a year to the same purpose.
The difficulties on our side of the Atlantic are greater than on the
American coasts, on account of the greater changeableness of our
weather—mainly due to the more irregular distribution of land and
water on this side. This, however, instead of discouraging national
effort, should be regarded as a reason for increasing it. The greater
the changes, the greater is the need for warnings, and the greater
the difficulty the greater should be the effort. With our multitude
of coastguard stations and naval men without employment, we ought to
surpass all the world in such a work as this.
Those among our readers who are sufficiently interested in this subject
to devote a little time to it, may make a very interesting weather
scrap-book by cutting out the newspaper chart for each day, pasting it
in a suitable album, and appending their own remarks on the weather at
the date of publication, _i.e._ the day after the chart observations
are made. Such an album would be far more interesting than the postage
stamp and monogram albums that are so abundant.
Parents who desire their children to acquire habits of systematic
observation, and to cultivate an intelligent interest in natural
phenomena, will do well to supply such albums to their sons or
daughters, and to hand over to them the daily paper for this purpose.
The Meteorological Office supplies by post copies of “Daily Weather
Reports” to any subscriber who pays five shillings per quarter in
advance; such subscriptions payable to Robt. H. Scott, Esq., Director
Meteorological Office, 116 Victoria Street, Westminster, S.W.
These daily reports are printed on a large double sheet, on one half of
which are four charts, representing separately the four records which
are included in the one smaller newspaper chart—viz., those of the
barometer, the thermometer, the rain-gauge, and the anemometer. On the
other half of the sheet is a detailed separate tabular statement of the
results of observations made at the following stations:
Haparanda
Hernösand
Stockholm
Wisby
Christiansund
Skudesnaes
Oxö (Christiansund)
Skagen (The Skaw)
Fanö
Cuxhaven
Sumburgh Head
Stornoway
Thurso
Wick
Nairn
Aberdeen
Leith
Shields
York
Scarborough
Nottingham
Ardrossan
Greencastle
Donaghadee
Kingstown
Holyhead
Liverpool
Valencia
Roche’s Point
Pembroke
Portishead
Scilly
Plymouth
Hurst Castle
Dover
London
Oxford
Cambridge
Yarmouth
The Helder
Cape Griznez
Brest
L’Orient
Rochefort
Biarritz
Corunna
Brussels
Charleville
Paris
Lyons
Toulon
_On Winds and Currents, from the Admiralty Physical Atlas._
In the Northern Hemisphere the effect of the veering of the wind on the
barometer is according to the following law:
With East, South-east, and South winds, the barometer falls.
With South-west winds, the barometer ceases to fall and begins to rise.
With West, North-west, and North winds, the barometer rises.
With North-east winds, the barometer ceases to rise and begins to fall.
In the Northern Hemisphere the thermometer rises with East, South-east,
and South winds; with a South-west wind it ceases to rise and begins
to fall; it falls with West, North-west, and North winds; and with a
North-east wind it ceases to fall and begins to rise.
THE CHEMISTRY OF BOG RECLAMATION.
The mode of proceeding for the reclamation of bog-land at Kylemore is
first to remove the excess of water by “the big drain and the secondary
drains,” which must be cut deep enough to go right down to the gravel
below. These are supplemented by the “sheep drains,” or surface-drains,
which are about twenty inches wide at top, and narrow downwards to six
inches at bottom. They run parallel to each other, with a space of
about ten yards between, and cost one penny per six yards.
This first step having been made, the bog is left for two years, during
which it drains, consolidates, and sinks somewhat. If the bog is deep,
the turf, which has now become valuable by consolidation, should be cut.
After this it is left about two years longer, with the drains still
open. Then the drains are cleared and deepened, and a wedge-shaped sod,
too wide to reach the bottom, is rammed in so as to leave below it a
permanent tubular covered drain, which is thus made without the aid of
any tiles or other outside material. The drainage is now completed, and
the surface prepared for the important operation of dressing with lime,
which, as the people expressively say, “boils the bog,” and converts it
into a soil suitable for direct agricultural operations.
Potatoes and turnips may now be set in “lazy bed” ridges. Mr. Mitchell
Henry says, “Good herbage will grow on the bog thus treated; but as
much as possible should at once be put into root-crops, with farm-yard
manure for potatoes and turnips. The more lime you give the better
will be your crop; and treated thus there is no doubt that even during
the first year land so reclaimed will yield remunerative crops.” And
further, that “after being broken up a second time the land materially
improves, and becomes doubly valuable.” Also that he has no doubt that
“all bog-lands may be thus reclaimed, but it is uphill work, and not
remunerative to attempt the reclamation of bogs that are more than four
feet in depth.”
There is another and a simpler method of dealing with bogs—viz.,
setting them into narrow ridges; cutting broad trenches between the
ridges; piling the turf cut out from these trenches into little heaps
a few feet apart, burning them, and spreading the ashes over the
ridges. This is rather largely practiced on the coast of Donegal, in
conjunction with sea-weed manuring, and is prohibited in other parts
of Ireland as prejudicial to the interests of the landlord.
We shall now proceed to the philosophy of these processes.
First, the drainage. Everybody in Ireland knows that the bog holds
water like a sponge, and in such quantities that ordinary vegetation
is rotted by the excess of moisture. There is good reason to believe
that the ancient forests, which once occupied the sites of most of the
Irish bogs, were in some cases destroyed by the rotting of their stems
and roots in the excess of vegetable soil formed by generations upon
generations of fallen leaves, which, in a humid climate like that of
Ireland, could never become drained or air-dried.
But this is not all. There is rotting and rotting. When the rotting
of vegetable matter goes on under certain conditions it is highly
favorable to the growth of other vegetation, even of the vegetation of
the same kind of plants as those supplying the rotting material. Thus,
rotten and rotting straw is a good manure for wheat; and the modern
scientific vine-grower carefully places the dressing of his vines about
their roots, in order that they may rot, and supply the necessary salts
for future growth. The same applies generally; rotting cabbage-leaves
supply the best of manure for cabbages; rotting rhubarb-leaves for
rhubarb; rose-leaves for rose-trees; and so on throughout the vegetable
kingdom.
Why, then, should the bog-rotting be so exceptionally malignant? As I
am not aware that any answer has been given to this question, I will
venture upon one of my own. It appears to be mainly due to the excess
of moisture preventing that slow combustion of vegetable carbon which
occurs wherever vegetable matter is heaped together and _slightly_
moistened. We see this going on in steaming dung-hills; in hayricks
that have been stacked when imperfectly dried; in the spontaneous
combustion of damp cotton in the holds of ships, and in factories where
cotton-waste has been carelessly heaped; and in cucumber-frames and the
other “hot-beds” of the gardener.
In ordinary soils this combustion goes on more slowly, but no less
effectively, than in these cases. In doing so it maintains a certain
degree of warmth about the roots of the plants that grow there, and
_gradually_ sets free the soluble salts which the rotting vegetables
contain, and supplies them to the growing plants as manure, at the same
time forming the humus so essential to vegetation.
A great excess of water, such as soddens the bog, prevents this, and
also carries away any small quantity of soluble nutritious salts the
soil may contain. Thus, instead of being warmed and nourished by slight
humidity, and consequent oxidation, the bog soil is chilled and starved
by excess of water.
The absolute necessity of the first operation—that of drainage—is
thus rendered obvious; and I suspect that the need of four years’ rest,
upon which Mr. MacAlister insists, is somehow connected with a certain
degree of slow combustion that accompanies and partially causes the
consolidation of the bog. I have not yet had an opportunity of testing
this by inserting thermometers in bogs under different conditions, but
hope to do so.
The liming next demands explanation. Mr. Henry says that “it leaves the
soil sweetened by the neutralization of its acids.”
In order to test this theory I have digested (_i.e._, soaked) various
samples of turf cut from Irish bogs in distilled water, filtered off
the water, and examined it. I find that when this soaking has gone far
enough to give the water a coloring similar to that which stands in
ordinary bogs, the acidity is very decided—quite sufficiently so to
justify this neutralization theory as a partial explanation. There is
little reason to doubt that the lime is further effective in enriching
the soil; or, in the case of pure bogs, that it forms the soil by
disintegrating and decomposing the fibrous vegetable matter, and thus
rendering it capable of assimilation by the crops.
Another effect which the lime must produce is the liberation of free
ammonia from any fixed salts that may exist in the bog.
The bog-burning method of reclamation is easily explained. In the first
place, the excessive vegetable encumbrance is reduced in quantity,
and the remaining ashes supply the surface of the bog on which they
rest with the non-volatile salts that originally existed in the burnt
portions of the bog. In other words, they concentrate in a small space
the salts that were formerly distributed too sparsely through the whole
of the turf which was burnt.
As there are great differences in the composition of different bogs,
especially in this matter of mineral ash, it is evident that the
success of this method must be very variable, according to the locality.
On discussing this method with Mr. MacAlister (Mr. Henry’s steward,
under whose superintendence these reclamation works are carried out),
he informed me that the bogs on the Kylemore estate yield a very small
amount of ash—a mere impalpable powder that a light breath might blow
away; that it was practically valueless, excepting from the turf taken
at nearly the base of the bog. The ash I examined where the bog-burning
is extensively practiced in Donegal, was quite different from this.
The quantity was far greater, and its substance more granular and
gritty. It, in fact, formed an important stratum, when spread over the
surface of the ridges. These differences of composition may account
for the differences of opinion and practice which prevail in different
districts. It affords a far more rational explanation than the
assumption that all such contradictions arise from local stupidities.
There is one evil, however, which is common to all bog-burning as
compared with liming—it must waste the ammoniacal salts, as they are
volatile, and are driven away into the air by the heat of combustion.
Somebody may get them when the rain washes them down to the earth’s
surface again; but the burner himself obtains a very small share in
this way.
We may therefore conclude that where lime is near at hand, bog-burning
is a rude and wasteful, a viciously indolent mode of reclamation. It
is only desirable where limestone is so distant that the expense of
carriage renders lime practically unattainable, and where the bog
itself is rich in mineral matter, and so deep and distant from a
fuel demand, that it may be burned to waste without any practical
sacrifice. Under such conditions it may be better to burn the bog than
leave it in hopeless and worthless desolation.
I cannot conclude without again adverting to the importance of this
subject, and affirming with the utmost emphasis, that the true Irish
patriot is not the political orator, but he who by practical efforts,
either as capitalist, laborer, or teacher, promotes the reclamation of
the soil of Ireland, or otherwise develops the sadly neglected natural
resources of the country.
With Mr. Mitchell Henry’s permission I append to the above his own
description of the results of his experiment, originally communicated
in a letter to the _Times_; at the same time thanking him for his kind
reception of a stranger at Kylemore Castle, and the facilities he
afforded me for studying the subject on the spot.
“The interesting account you lately published of the extensive
reclamations of His Grace the Duke of Sutherland, under the title
of ‘An Agricultural Experiment,’ has been copied into very many
newspapers, and must have afforded a welcome relief to thousands of
readers glad to turn for a time from the terrible narratives that come
to us from the east. If you will allow me, I should like to supplement
your narrative by a rapid sketch of what has been done here during the
last few years, on a much humbler scale, in the case of land similar,
and some of it almost identical, with that in Sutherlandshire.
“The twelve _corps d’armée_ under the Duke’s command, in the shape
of the twelve steam-engines and their ploughs, engaged in subduing
the stubborn resistance of the unreclaimed wilds of Sutherlandshire,
suggest to the mind the triumphs of great warriors, and fill us with
admiration—not always excited by the details of great battle; but, as
great battles can be fought seldom, and only by gigantic armies and at
prodigious expense, so reclamation on such a scale is far beyond the
opportunities or the means of most of us; while many may, perhaps, be
encouraged to attempt work similar to that which has been successfully
carried out here.
“And, first of all, a word as to the all-important matter of cost. Does
it pay?
“Including farm-buildings and roads, the reclamations here have cost
on an average 13_l._ an acre, which, at 5 per cent, means an annual
rent-charge of 13_s._, to which is to be added a sum of from 1_s._ to
3_s._, the full annual value of the unreclaimed land. It is obvious
that if we start with an outlay of 30_l._ _plus_ the 1_s._ to 3_s._ of
original rent, such an amount would usually be found prohibitory; but,
on the other hand, excellent profits may be made if the expenditure
is so kept down that the annual rent is not more than from 15_s._ to
18_s._ per acre. Before entering into further details, let me say that
I claim no credit for originality in what has been done. The like has
been effected on numerous properties in Ireland in bygone days, and is
daily being carried out by the patient husbandman who year by year with
his spade reclaims a little bit from the mountain side. And you must
allow me emphatically to say that what has been done here economically
and well would not have been done except for the prudence, patience,
and thoughtful mind of my steward, Archibald MacAlister, a County
Antrim man, descended from one of the race of Highland Catholic Scotch
settlers, who have peopled the north of Ireland and added so much to
its prosperity.
“The Pass of Kylemore, in which I live, is undoubtedly favorably
situated for reclamation, for there is but little very deep bog, and
there is abundance of limestone. In former ages it must have been an
estuary of the sea, with a river flowing through it, now represented
by a chain of lakes and the small rapid river Dowris. The subsoil is
sand, gravel, and schist rock, with peat of various depths grown upon
it. As by the elevation of the land the sea long ages ago was driven
back, the mossy growth of peat commenced, followed by pine and yew
trees, of which the trunks and roots are abundantly found; but, except
over a space of about 400 acres, every tree that formerly clothed the
hillsides has been cut down or has totally disappeared. The general
result is that we have a pass several miles long, bounded on the north
and south by a chain of rugged mountains of some 1500 or 1800 feet in
height, while the east is blocked up by a picturesque chain running
north and south, and separating the Joyce country from Connemara
proper, the west being open to the Atlantic. The well-known Killery
Bay, or Fiord, would, I doubt not, present an exact resemblance to
Kylemore if the sea, which now flows up to its head, were driven out.
There are miles of similar country in Ireland, waiting only for the
industry of man, where, as here, there exist extensive stretches of
undulating eskers, covered with heather growing on the light clay, with
a basis of gravel or sand.
“A considerable difference exists between the reclamation of the flat
parts, where the bog is pretty deep, and the hillsides, where there is
little or no bog. Yet it is to be remembered that bog is nothing more
than vegetable matter in a state of partial decomposition, and holding
water like a sponge. The first thing is to remove the water by drains,
some of which—that is, the big drain and the secondary drains—must
go right down to the gravel below; but the other drains—called
sheep-drains—need not, and, indeed, must not be cut so deep. The
drains are cut wedge-shape by what are called Scotch tools, which
employ three men—two to cut and one to hook out the sods; and all that
is requisite to form a permanent drain is to replace the wedge-shaped
sod, and ram it down between the walls of the drain, where it
consolidates and forms a tube which will remain open for an indefinite
number of years. We have them here as good as new, made twenty-five
years ago; and at Chat Moss, in Lancashire, they are much older. After
land has been thus drained—but not too much drained, or it will become
dry turf—the surface begins to sink; what was tumid settles down, and
in the course of a few months the land itself becomes depressed on the
surface and much consolidated. Next it is to be dug by spade-labor or
ploughed. We use oxen largely for this purpose, and, strange to say,
the best workers we find to be a cross with the Alderney, the result
being a light, wiry little animal, which goes gayly over the ground,
is easy to feed, and is very tractable. The oxen are trained by the
old wooden neck-yoke; but, when well broken, work in collars, which
seem more easy to them. Horses on very soft land work well in wooden
pattens. After the land has been broken up, a good dressing of lime is
to be applied to it, and this, in the expressive language of the people
here, ‘boils the bog’—that is, the lime causes the vegetable matter,
formerly half decomposed, to become converted into excellent manure.
This leaves the soil sweetened by the neutralization of its acids, and
in a condition pretty easily broken up by the chain-harrow; or, what is
better still, by Randall’s American revolving harrow.
“Good herbage will grow on bog thus treated, but as much as possible
should at once be put into root-crops, with farmyard manure for
potatoes and turnips. The more lime you give the better will be your
crop, and, treated thus, there is no doubt that even during the first
year, land so reclaimed will yield remunerative crops. People ask, ‘But
will not the whole thing go back to bog?’ Of course it will if not kept
under proper rotation, which we find to be one of five years—namely,
roots followed by oats, laid down with clover and grass seed, which
remains for two years. After being broken up a second time, the land
materially improves and becomes doubly valuable. I have no doubt that
all bog-lands may be thus reclaimed, but it is up-hill work and not
remunerative to attempt the reclamation of bogs that are more than four
feet in depth.
“And here I will make a remark as to the effects of drainage in a wet
country. By no means does the whole effect result from raising the
temperature of the soil; there is something else as important, and
that is the supply of ammonia, brought down from the skies in the
rain, which, with other fertilizing matter, is caught, detained, and
absorbed in the soil. A well-drained field becomes, in fact, just like
a water-meadow over which a river flows for a part of a year; and thus
the very wetness of the climate may be made to reduce the supply of
ammoniacal manures, so expensive to buy.
“The porous, well-drained soil carries quickly off the superfluous
moisture, while the ammonia is absorbed by the roots and leaves of the
plants. An excessive bill for ammoniacal manures has been the ruin of
many a farmer; and our aim in Ireland should be to secure good crops
by thorough drainage and constant stirring of the soil, without much
outlay for concentrated manures. At the same time I ought to remark
that we have grown excellent potatoes by using 5_l._ worth per acre
of superphosphate and nitrate of soda in cases in which our farmyard
manure has fallen short.
“The reclamation of mountain-land as distinguished from bog-land can
best be illustrated by a record of what has been accomplished on two
farms here. Three years ago the leases of two upland farms fell in,
and I took them into my own hands. The first consists of 600 acres,
one-half a nearly level flat of deepish bog running alongside the
river, the other half moor heath, which with difficulty supported a few
sheep and cattle.
“There had never been any buildings on this land, nor had a spade ever
been put into it; and the tenant, being unable to pay his rent of
15_l._ a year for the 600 acres, was glad to give it up for a moderate
consideration. The first thing accomplished was to fence and drain
thoroughly as before described, and the best half of the land was then
divided into forty-acre fields. Exactly now two years ago—on September
15th—a little cottage and a stable for a pair of horses and a pair
of bullocks was completed and tenanted by two men and a boy. They
ploughed all the week and came home on Saturdays to draw their supply
of food and fodder for the ensuing seven days, thus approximating very
nearly to the position of settlers in a new country. We limed all the
land we could, manured part of it with seaweed and part with the farm
manure made by the horses and oxen which were at work, and cropped with
roots such as turnips and potatoes. A good portion we sowed with oats
out of the lea, but the most satisfactory crop we found to be rape
and grasses mixed, for on the best of the land they form at once an
excellent permanent pasture. We have now had two crops from this land;
and I venture to say that the thirteen stacks of oats and hay gathered
in in good condition, and the turnips and roots now growing, which
are not excelled in the county Galway—except those of Lord Clancarty
at Ballinasloe, who has grown 110 tons of turnips to the Irish acre,
equal to upwards of 68 tons to the acre here—present a picture most
gratifying and cheering in every way.
“The second farm, of 240 acres, which adjoins this, had a good building
on it; but, having been let on lease at about 10_s._ an acre to a large
grazier whose stock-in-trade was a horse, a saddle, and a pair of
shears, had not been cultivated or improved.
“Similar proceedings on this farm have produced similar results; and,
if now let in the market, I have no doubt that after two years of good
treatment these farms would be let at 20_s._ an acre, and I do not
despair of doubling this figure in the course of time.
“The exact weight of the turnip crop this season is, on raw bog,
drained, limed, and cropped this year for the first time, 24 tons per
acre; manure, seaweed. On land ploughed but not cropped, last year
23½ tons; mixed mineral manure. On land from which a crop of oats had
previously been taken, 29 tons; manure, farmyard, with 3 cwt. per acre
mineral manure.
“Last year my excellent steward, Mr. MacAlister, visited the Duke of
Sutherland’s reclamations in Scotland, and was kindly and hospitably
received. He found the land and the procedure adopted almost identical,
with the conviction that oxen and horses will suit us better at the
present time than steam culture, chiefly on the score of economy. He
also visited the Bridgewater Estate at Chat Moss, near Manchester,
where so much has been done to bring the deep peat into cultivation,
and he found the system that has been followed there for so many years
to be like that described above, marl, however, being used in the place
of lime.”
At the time of my visit to Kylemore the hay crops were down and partly
carried on the reclaimed bog-land above described. The contrast of its
luxuriance with the dark and dreary desolation of the many estates I
had seen during three summers’ wanderings through Ireland added further
proof of the infamy of the majority of Irish landlords, by showing what
Ireland would have been had they done their duty.
AERIAL EXPLORATION OF THE ARCTIC REGIONS.
On our own hemisphere, and separated from our own coasts by only a
few days’ journey on our own element, there remains a blank circle of
unexplored country above 800 miles in diameter. We have tried to cross
it, and have not succeeded. Nothing further need be said in reply to
those who ask, “Why should we start another Arctic Expedition?”
The records of previous attempts to penetrate this area of geographical
mystery prove the existence of a formidable barrier of mountainous
land, fringed by fjords or inlets, like those of Norway, some of which
may be open, though much contracted northward, like the Vestfjord that
lies between the Lofoden Islands and the mainland of Scandinavia. The
majority evidently run inland like the ordinary Norwegian fjords or the
Scotch firths, and terminate in land valleys that continue upwards to
fjeld regions, or elevated humpy land which acts as a condenser to the
vapor-laden air continually flowing towards the Pole from the warmer
regions of the earth, and returning in lower streams when cooled. The
vast quantities of water thus condensed fall upon these hills and table
lands as snow crystals. What becomes of this everlasting deposit?
Unlike the water that rains on temperate hill-sides, it cannot all
flow down to the sea as torrents and liquid rivers, but it does come
down nevertheless, or long ere this it would have reached the highest
clouds. It descends mainly as glaciers, which creep down slowly, but
steadily and irresistibly, filling up the valleys on their way; and
stretching outwards into the fjords and channels, which they block up
with their cleft and chasmed crystalline angular masses that still
creep outward to the sea until they float, and break off or “calve” as
mountainous icebergs and smaller masses of ice.
These accumulations of ice thus _formed on land_ constitute the chief
obstructions that bar the channels and inlets fringing the unknown
Polar area. The glacier fragments above described are cemented together
in the winter time by the freezing of the water between them. An open
frozen sea, pure and simple, instead of forming a barrier to arctic
exploration, would supply a most desirable highway. It must not be
supposed that, because the liquid ocean is ruffled by ripples, waves,
and billows, a frozen sea would have a similar surface. The freezing
of such a surface could only start at the calmest intervals, and the
ice would shield the water from the action of the wave-making wind,
and such a sea would become a charming skating rink, like the Gulf
of Bothnia, the Swedish and Norwegian lakes, and certain fjords,
which, in the winter time, become natural ice-paved highways, offering
incomparable facilities for rapid locomotion. In spite of the darkness
and the cold, winter is the traveling season in Sweden and Lapland.
The distance that can be made in a given time in summer with a wheeled
vehicle on well-made post roads can be covered in half the time in a
_pulk_ or reindeer sledge drawn over the frozen lakes. From Spitzbergen
to the Pole would be an easy run of five or six days if nothing but a
simply frozen sea stood between them.
This primary physical fact, that arctic navigators have not been
stopped by a merely frozen sea, but by a combination of glacier
fragments with the frozen water of bays, and creeks, and fjords, should
be better understood than it is at present; for when it is understood,
the popular and fallacious notion that the difficulties of arctic
progress are merely dependent on latitude, and must therefore increase
with latitude, explodes.
_It is the physical configuration of the fringing zone of the arctic
regions, not its mere latitude, that bars the way to the Pole._
I put this in italics because so much depends upon it—I may say that
all depends upon it—for if this barrier can be scaled at any part we
may come upon a region as easily traversed as that part of the Arctic
Ocean lying between the North Cape and Spitzbergen, which is regularly
navigated every summer by hardy Norsemen in little sailing sloops of
30 to 40 tons burden, and only six or eight pair of hands on board; or
by overland traveling as easily as the Arctic winter journey between
Tornea and Alten. This trip over the snow-covered mountains is done
in five or six days, at the latter end of every November, by streams
of visitors to the fair at Alten, in latitude 70°, 3½ degrees N. of
the Arctic circle; its distance, 430 miles, is just about equal to
that which stands between the North Pole and the northernmost reach of
our previous Arctic expeditions. One or the other of the above-named
conditions, or an enclosed frozen Polar ocean, is what probably exists
beyond the broken fjord barrier hitherto explored; a continuation
of such a barrier is, in fact, almost a physical impossibility; and
therefore the Pole will be ultimately reached, not by a repetition of
such weary struggles as those which ended in the very hasty retreat of
our last expedition, but by a bound across about 400 miles of open or
frozen Polar ocean, or a rapid sledge-run over snow-paved fields like
those so merrily traversed in Arctic Norway by festive bonders and
their families on their way to Yule-time dancing parties.
Reference to a map of the circumpolar regions, or, better, to a globe,
will show that the continents of Europe, Asia, and America surround the
Pole, and hang, as it were, downwards or southwards from a latitude of
70° and upwards. There is but one wide outlet for the accumulations
of Polar ice, and that is between Norway and Greenland, with Iceland
standing nearly midway. Davis’s and Behring’s Straits are the narrower
openings; the first may be only a fjord, rather than an outlet. The
ice-block, or crowding together and heaping up of the glacier fragments
and bay ice, is thus explained.
Attempts of two kinds have been made to scale this icy barrier. Ships
have sailed northwards, threading a dangerous course between the
floating icebergs in the summer, and becoming fast bound in winter,
when the narrow spaces of brackish water lying between these masses
of land ice become frozen, and the “ice-foot” clinging to the shore
stretches out seaward to meet that on the opposite side of the fjord or
channel. The second method, usually adopted as supplementary to the
first, is that of dragging sledges over these glacial accumulations.
The pitiful rate of progress thus attainable is shown by the record
of the last attempt, when Commander Markham achieved about one mile
per day, and the labor of doing this was nearly fatal to his men. Any
tourist who has crossed or ascended an Alpine glacier with only a
knapsack to carry, can understand the difficulty of dragging a cartload
of provisions, etc., over such accumulations of iceberg fragments and
of sea-ice squeezed and crumbled up between them. It is evident that we
must either find a natural breach in this Arctic barrier or devise some
other means of scaling it.
The first of these efforts has been largely discussed by the advocates
of rival routes. I will not go into this question at present, but only
consider the alternative to all land routes and all water routes, viz.:
that by the other available element—an aerial route—as proposed to be
attempted in the new Arctic expedition projected by Commander Cheyne,
and which he is determined to practically carry out, provided his own
countrymen, or, failing them, others more worthy, will assist him with
the necessary means of doing so.
To reach the Pole from the northernmost point already attained by our
ships demands a journey of about 400 miles, the distance between London
and Edinburgh. With a favorable wind, a balloon will do this in a few
hours, On November 27, 1870, Captain Roher descended near Lysthuus, in
Hitterdal (Norway), in the balloon “Ville d’Orleans,” having made the
journey from Paris in fifteen hours. The distance covered was about
900 miles, more than double the distance between the Pole and the
accessible shores of Greenland.
On November 7, 1836, Messrs. Holland, Mason, and Green ascended from
Vauxhall Gardens, at 1.30 P.M., with a _moderate breeze_, and descended
eighteen hours afterwards “in the Duchy of Nassau, about two leagues
from the town of Weilburg,” the distance in a direct line being about
500 miles. A similar journey to this would carry Commander Cheyne from
his ship to the North Pole, or thereabouts, while a fresh breeze
like that enjoyed by Captain Roher would, in the same time, carry him
clear across the whole of the circumpolar area to the neighborhood of
Spitzbergen, and two or three hours more of similar proceeding would
land him in Siberia or Finland, or even on the shores of Arctic Norway,
where he could take the Vadsö or Hammerfest packet to meet one of
Wilson’s liners at Trondhjem or Bergen, and thus get from the North
Pole to London in ten days.
Lest any of my readers should think that I am writing this at
random, I will supply the particulars. I have before me the “Norges
Communicationer” for the present summer season of 1880. Twice every
week a passenger excursion steam packet sails round the North Cape
each way, calling at no less than twenty stations on this Arctic face
of Europe to land and embark passengers and goods. By taking that
which stops at Gjesvaer (an island near the foot of the North Cape)
on Saturday, or that which starts from Hammerfest on Sunday morning,
Trondhjem is reached on Thursday, and Wilson’s liner, the “Tasso,”
starts on the same day for Hull, “average passage seventy hours.” Thus
Hammerfest, the northernmost town in the world, is now but eight days
from London, including a day’s stop at Tromsö, the capital of Lapland,
which is about 3 degrees N. of the Arctic circle, and within a week
of London. At Captain Roher’s rate of traveling Tromsö would be but
twenty-three hours from the Pole.
These figures are, of course, only stated as _possibilities_ on the
supposition that all the conditions should be favorable, but by no
means as _probable_.
What, then, are the _probabilities_ and the amount of risk that will
attend an attempt to reach the Pole by an aerial route?
I have considered the subject carefully, and discussed it with
many people; the result of such reflection and conversation is a
conviction that the prevalent popular estimate of the dangers of
Commander Cheyne’s project extravagantly exaggerates them on almost
all contingencies. I do not affirm that there is no risk, or that the
attempt should be made with only our present practical knowledge of
the subject, but I do venture to maintain that, after making proper
preliminary practical investigations at home, a judiciously conducted
aerostatic dash for the Pole will be far less dangerous than the
African explorations of Livingstone, Stanley, and others that have been
accomplished and are proposed. And further, that a long balloon journey
starting in summer-time from Smith’s Sound, or other suitable Arctic
station, would be less dangerous than a corresponding one started from
London; that it would involve less risk than was incurred by Messrs.
Holland, Mason, and Green, when they traveled from Vauxhall Gardens to
Nassau.
The three principal dangers attending such a balloon journey are: 1st.
The variability of the wind. 2d. The risk of being blown out about the
open ocean beyond the reach of land. 3d. The utter helplessness of
the aeronaut during all the hours of darkness. I will consider these
seriatim in reference to Arctic ballooning _versus_ Vauxhall or Crystal
Palace ballooning.
As regards the first danger, Vauxhall and Sydenham are in a position
of special disadvantage, and all the ideas we Englishmen may derive
from our home ballooning experience must tend to exaggerate our common
estimate of this danger, inasmuch as we are in the midst of the region
of variable winds, and have a notoriously uncertain climate, due to
this local exaggeration of the variability of atmospheric movements. If
instead of lying between the latitudes of 50° and 60°, where the N.E.
Polar winds just come in collision with the S.W. tropical currents, and
thereby effect our national atmospheric stir-about, we were located
between 10° and 30° (where the Canary Islands are, for example),
our notions on the subject of balloon traveling would be curiously
different. The steadily blowing trade-wind would long ere this have led
us to establish balloon mails to Central and South America, and balloon
passenger expresses for the benefit of fast-going people or luxurious
victims of sea-sickness. To cross the Atlantic—three thousand
miles—in forty-eight hours, would be attended with no other difficulty
than the cost of the gas, and that of the return carriage of the empty
balloon.
It is our exceptional meteorological position that has generated the
popular expression “as uncertain as the wind.” We are in the very
centre of the region of meteorological uncertainties, and cannot
go far, either northward or southward, without entering a zone of
greater atmospheric regularity, where the direction of the wind at a
given season may be predicted with more reliability than at home. The
atmospheric movements in the Arctic regions appear to be remarkably
regular and gentle during the summer and winter months, and irregular
and boisterous in spring and autumn. A warm upper current flows from
the tropics towards the Pole, and a cold lower one from the Arctic
circle towards the equator. Commander Cheyne, who has practical
experience of these Arctic expeditions, and has kept an elaborate log
of the wind, etc., which he has shown me, believes that, by the aid
of pilot balloons to indicate the currents at various heights, and by
availing himself of these currents, he may reach the Pole and return
to his ship, or so near as to be able to reach it by traveling over
the ice in light sledges that will be carried for that purpose. In
making any estimate of the risk of Arctic aerostation, we must banish
from our minds the preconceptions induced by our British experience
of the uncertainties of the wind, and only consider the atmospheric
actualities of the Polar regions, so far as we know them.
Let us now consider the second danger, viz., that of being blown out
to sea and there remaining until the leakage of gas has destroyed the
ascending power of the balloon, or till the stock of food is consumed.
A glance at a map of the world will show how much smaller is the danger
to the aeronaut who starts from the head of Baffin’s Bay than that
which was incurred by those who started from Vauxhall in the Nassau
balloon, or by Captain Roher, who started from Paris. Both of these had
the whole breadth of the Atlantic on the W. and S.W., and the North
Sea and Arctic Ocean N. and N.E. The Arctic balloon, starting from
Smith’s Sound or thereabouts, with a wind from the South (and without
such a wind the start would not, of course, be made), would, if the
wind continued in the same direction, reach the Pole in a few hours;
in seven or eight hours at Roher’s speed; in fourteen or fifteen
hours at the average rate made by the Nassau balloon in a “moderate
breeze.” Now look again at the map and see what surrounds them. Simply
the continents of Europe, Asia, and America, by which the circumpolar
area is nearly land-locked, with only two outlets, that between Norway
and Greenland on one side, and the narrow channel of Behring’s Straits
on the other. The wider of these is broken by Spitzbergen and Iceland,
both inhabited islands, where a balloon may descend and the aeronauts
be hospitably received. Taking the 360 degrees of the zone between the
70th parallel of latitude and the Arctic circle, 320 are land-locked
and only 40 open to the sea; therefore the chances of coming upon land
at _any one_ part of this zone is as 320 to 40; but with a choice of
points for descent such as the aeronauts would have unless the wind
blew precisely down the axis of the opening, the chances would be far
greater. If the wind continued as at starting, they would be blown to
Finland; a westerly deflection would land them in Siberia, easterly in
Norway; a strong E. wind at the later stage of the trip would blow them
back to Greenland.
In all the above I have supposed the aeronauts to be quite helpless,
merely drifting at random with that portion of the atmosphere in
which they happened to be immersed. This, however, need not be the
case. Within certain limits they have a choice of winds, owing to the
prevalence of upper and lower currents blowing in different and even in
opposite directions. Suppose, for example, they find themselves N. of
Spitzbergen, where “Parry’s furthest” is marked on some of our maps,
and that the wind is from the N.E., blowing them towards the Atlantic
opening. They would then ascend or descend in search of a due N. or N.
by W. wind that would blow them to Norway, or W.N.W. to Finland, or
N.W. to Siberia, or due E. back to Greenland, from whence they might
rejoin their ships. One or other of these would almost certainly be
found. A little may be done in steering a balloon, but so very little
that small reliance should be placed upon it. Only in a very light
wind would it have a sensible effect, though in case of a “near shave”
between landing, say at the Lofodens or Iceland, and being blown out
to sea, it might just save them.
As already stated, Commander Cheyne believes in the possibility of
returning to the ship, and bases his belief on the experiments he made
from winter quarters in Northumberland Sound, where he inflated four
balloons, attached to them proportionately different weights, and sent
them up simultaneously. They were borne by diverse currents of air in
_four different directions according to the different altitudes_, viz.,
N.W., N.E., S.E., and S.W., “thus proving that in this case balloons
could be sent in any required direction by ascending to the requisite
altitude. The war balloon experiments at Woolwich afford a practical
confirmation of this important feature in aerostation.” Cheyne proposes
that one at least of the three balloons shall be a rover to cross the
unknown area, and has been called a madman for suggesting this merely
as an alternative or secondary route. I am still more lunatic, for
I strongly hold the opinion that the easiest way for him to return
to his ship will be to drift rapidly across to the first available
inhabited land, thence come to England, and sail in another ship to
rejoin his messmates; carrying with him his bird’s-eye chart, that
will demonstrate once for all the possibility or impossibility of
circumnavigating Greenland, or of sailing, or sledging, or walking to
the Pole.
The worst dilemma would be that presented by a dead calm, and it is not
improbable that around the Pole there may be a region of calms similar
to that about the Equator. Then the feather-paddle or other locomotive
device worked by man-power would be indispensable. Better data than we
at present possess are needed in order to tell accurately what may thus
be done. Putting various estimates one against the other, it appears
likely that five miles an hour may be made. Taking turn and turn about,
two or three aeronauts could thus travel fully 100 miles per day, and
return from the Pole to the ship in less than five days.
Or take the improbable case of a circular wind blowing round the Pole,
as some have imagined. This would simply demand the working of the
paddle always northwards in going to the Pole, and always southwards in
returning. The resultant would be a spiral course winding inwards in
the first case, and outwards in the second. The northward or southward
progress would be just the same as in a calm if the wind were truly
concentric to the Pole. Some rough approximation to such currents may
exist, and might be dealt with on this principle.
Let us now consider the third danger, that of the darkness. The
seriousness of this may be inferred from the following description
of the journey of the Nassau balloon, published at the time: “It
seemed to the aeronauts as if they were cleaving their way through
an interminable mass of black marble in which they were imbedded,
and which, solid a few inches before them, seemed to soften as they
approached in order to admit them still further within its cold and
dusky enclosure. In this way they proceeded blindly, as it may well be
called, until about 3.30 A.M., when in the midst of the impenetrable
darkness and profound stillness an unusual explosion issued from the
machine above, followed by a violent rustling of the silk, and all the
signs which might be supposed to accompany the bursting of the balloon.
The car was violently shaken. A second and a third explosion followed
in quick succession. The danger seemed immediate, when suddenly the
balloon recovered her usual form and stillness. These alarming symptoms
seemed to have been produced by collapsing of the balloon under the
diminished temperature of the upper regions after sunset, and the
silk forming into folds under the netting. Now, when the guide rope
informed the voyagers that the balloon was too near the earth, ballast
was thrown out, and the balloon rising rapidly into a thinner air
experienced a diminution of pressure, and consequent expansion of the
gas.
“The cold during the night ranged from a few degrees below to the
freezing point. As morning advanced the rushing of waters was heard,
and so little were the aeronauts aware of the course which they had
been pursuing during the night, that they supposed themselves to have
been thrown back upon the shores of the German Ocean, or about to enter
the Baltic, whereas they were actually over the Rhine, not far from
Coblentz.”
All this blind drifting for hours, during which the balloon may be
carried out to sea, and opportunities of safe descent may be lost, is
averted in an Arctic balloon voyage, which would be made in the summer,
when the sun never sets. There need be no break in the survey of the
ground passed over, no difficulty in pricking upon a chart the course
taken and the present position at any moment. With an horizon of 50 to
100 miles’ radius the approach of such a danger as drifting to the open
ocean would be perceived in ample time for descent, and as a glance
at the map will show, this danger cannot occur until reaching the
latitudes of inhabited regions.
The Arctic aeronauts will have another great advantage over those who
ascend from any part of England. They can freely avail themselves
of Mr. Green’s simple but most important practical invention—the
drag-rope. This is a long and rather heavy rope trailing on the ground.
It performs two important functions. First, it checks the progress of
the balloon, causing it to move less rapidly than the air in which it
is immersed. The aeronaut thus gets a slight breeze equivalent to the
difference between the velocity of the wind and that of the balloon’s
progress. He may use this as a fulcrum to effect a modicum of steerage.
The second and still more important use of the drag-rope is the very
great economy of ballast it achieves. Suppose the rope to be 1000 feet
long, its weight equal to 1 lb. for every ten feet, and the balloon
to have an ascending power of 50 lbs. It is evident that under these
conditions the balloon will retain a constant elevation of 500 feet
above the ground below it, and that 500 feet of rope will trail upon
the ground. Thus, if a mountain is reached no ballast need be thrown
away in order to clear the summit, as the balloon will always lift its
500 feet of rope, and thus always rise with the up-slope and descend
with the down-slope of hill and dale. The full use of this simple and
valuable adjunct to aerial traveling is prevented in such a country as
ours by the damage it might do below, and the temptation it affords to
mischievous idiots near whom it may pass.
In the course of many conversations with various people on this
subject I have been surprised at the number of educated men and women
who have anticipated with something like a shudder the terrible cold to
which the poor aeronauts will be exposed.
This popular delusion which pictures the Arctic regions as the abode of
perpetual freezing, is so prevalent and general, that some explanation
is demanded.
The special characteristic of Arctic climate is a cold and long winter
and a short and _hot summer_. The winter is intensely cold simply
because the sun never shines, and the summer is very hot because the
sun is always above the horizon, and, unless hidden by clouds or mist,
is continually shining. The summer heat of Siberia is intense, and the
vegetable proportionately luxuriant. I have walked over a few thousand
miles in the sunny South, but never was more oppressed with the heat
than in walking up the Tromsdal to visit an encampment of Laplanders in
the summer of 1856.
On the 17th July I noted the temperature on board the steam packet
when we were about three degrees north of the Arctic circle. It stood
at 77° well shaded in a saloon under the deck; it was 92° in the “rōk
lugar,” a little smoking saloon built on deck; and 108° in the sun on
deck. This was out at sea, where the heat was less oppressive than on
shore. The summers of Arctic Norway are very variable on account of the
occasional prevalence of misty weather. The balloon would be above much
of the mist, and would probably enjoy a more equable temperature during
the twenty-four hours than in any part of the world where the sun sets
at night.
I am aware that the above is not in accordance with the experience of
the Arctic explorers who have summered in such places as Smith’s Sound.
I am now about to perpetrate something like a heresy by maintaining
that the summer climate there experienced by these explorers is quite
exceptional, is not due to the latitude, but to causes that have
hitherto escaped the notice of the explorers themselves and of physical
geographers generally. The following explanation will probably render
my view of this subject intelligible:
As already stated, the barrier fringe that has stopped the progress of
Arctic explorers is a broken mountainous shore down which is pouring
a multitude of glaciers into the sea. The ice of these glaciers is,
of course, fresh-water ice. Now, we know that when ice is mixed with
salt water we obtain what is called “a freezing mixture”—a reduction
of temperature far below the freezing point, due to the absorption of
heat by the liquefaction of the ice. Thus the heat of the continuously
shining summer sun _at this particular part of the Arctic region_ is
continuously absorbed by this powerful action, and a severity quite
exceptional is thereby produced. Every observant tourist who has
crossed an Alpine glacier on a hot summer day has felt the sudden
change of climate that he encounters on stepping from _terra firma_ on
to the ice, and in which he remains immersed as long as he is on the
glacier. How much greater must be this depression of temperature where
the glacier ice is broken up and is floating in sea-water, to produce a
vast area of freezing mixture, which would speedily bring the hottest
blasts from the Sahara down to many degrees below the freezing point.
A similar cause retards the _beginning_ of summer in Arctic Norway and
in Finland and Siberia. So long as the winter snow remains unmelted,
_i.e._, till about the middle or end of June, the air is kept cold,
all the solar heat being expended in the work of thawing. This work
finished, then the warming power of a non-setting sun becomes evident,
and the continuously accumulating heat of his rays displays its
remarkable effect on vegetable life, and everything capable of being
warmed. These peculiarities of Arctic climate must become exaggerated
as the Pole is approached, the winter cold still more intense, and
the accumulation of summer heat still greater. In the neighborhood
of the North Cape, where these contrasts astonish English visitors,
where inland summer traveling becomes intolerable on account of the
clouds of mosquitoes, the continuous sunshine only lasts from May 11
to August 1. At the North Pole the sun would visibly remain above the
horizon during about seven months—from the first week in March to the
first week in October (this includes the effect of refraction and the
prolonged summer of the northern hemisphere due to the eccentricity of
the earth’s orbit).
This continuance of sunshine, in spite of the moderate altitude of
the solar orb, may produce a very genial summer climate at the Pole.
I say “may,” because mere latitude is only one of the elements of
climate, especially in high latitudes. Very much depends upon surface
configuration and the distribution of land and water. The region in
which our Arctic expedition ships have been ice-bound combines all the
most unfavorable conditions of Arctic summer climate. It is extremely
improbable that those conditions are maintained all the way to the
Pole. We know the configuration of Arctic Europe and Arctic Asia,
that they are masses of land spreading out northward round the Arctic
circle and narrowing southward to angular terminations. The southward
configuration and northward outspreading of North America are the same,
but we cannot follow the northern portion to its boundary as we may
that of Europe and Asia, both of which terminate in an Arctic Ocean.
Greenland is remarkably like Scandinavia; Davis’s Strait, Baffin’s
Bay, and Smith’s Sound corresponding with the Baltic and the Gulf of
Bothnia. The deep fjords of Greenland, like those of Scandinavia, are
on its western side, and the present condition of Greenland corresponds
to that of Norway during the milder period of the last glacial epoch.
If the analogy is maintained a little further north than our explorers
have yet reached we must come upon a Polar sea, just as we come upon
the White Sea and the open Arctic Ocean if we simply travel between 400
and 500 miles due north from the head of the frozen Gulf of Bothnia.
Such a sea, if unencumbered with land ice, will supply the most
favorable conditions for a genial arctic summer, especially if it be
dotted with islands of moderate elevation, which the analogies of
the known surroundings render so very probable. Such islands may be
inhabited by people who cannot reach us on account of the barrier wall
that has hitherto prevented us from discovering them. Some have even
supposed that a Norwegian colony is there imprisoned. Certainly the
early colonists of Greenland have disappeared, and their disappearance
remains unexplained. They may have wandered northwards, mingled with
the Esquimaux, and have left descendants in this unknown world. If any
of Franklin’s crew crawled far enough they may still be with them,
unable to return.
In reference to these possibilities it should be noted that a barrier
fringe of mountainous land like that of Greenland and arctic America
would act as a condensing ground upon the warm air flowing from the
south, and would there accumulate the heavy snows and consequent
glaciers, just as our western hills take so much of the rain from the
vapor-laden winds of the Atlantic. The snowfall immediately round the
Pole would thus be moderated, and the summer begin so much earlier.
I have already referred to the physical resemblances of Baffin’s Bay,
Smith’s Sound, etc., to the Baltic, the Gulf of Bothnia, and Gulf of
Finland. These are frozen every winter, but the Arctic Ocean due north
of them is open all the winter, and every winter. The hardy Norse
fishermen are gathering their chief harvest of cod fish in the open
sea around and beyond the North Cape, Nordkyn, etc., at the very time
when the Russian fleet is hopelessly frozen up in the Gulf of Finland.
But how far due north of this frozen Baltic are these open-sea fishing
banks? More than 14 degrees—more than double the distance that lies
between the winter quarters of some of our ships in Smith’s Sound
and the Pole itself. This proves how greatly physical configuration
and oceanic communication may oppose the climatic influences of mere
latitude. If the analogy between Baffin’s Bay and the Baltic is
complete, a Polar sea will be found that is open in the summer at least.
On the other hand, it may be that ranges of mountains covered with
perpetual snow, and valleys piled up with huge glacial accumulations,
extend all the way to the Pole, and thus give to our globe an arctic
ice-cap like that displayed on the planet Mars. This, however, is very
improbable, for, if it were the case, we ought to find a circumpolar
ice-wall like that of the antarctic regions; the Arctic Ocean beyond
the North Cape should be crowded with icebergs instead of being
open and iceless all the year round. With such a configuration the
ice-wall should reach Spitzbergen and stretch across to Nova Zembla;
but, instead of this, we have there such an open stretch of arctic
water, that in the summer of 1876 Captain Kjelsen, of Tromsö, sailed
in a whaler to lat. 81° 30´ without sighting ice. He was then but 510
geographical miles from the Pole, with open sea right away to his north
horizon, and nobody can say how much farther.
These problems may all be solved by the proposed expedition. The
men are ready and willing; one volunteer has even promised 1000_l._
on condition that he shall be allowed to have a seat in one of the
balloons. All that is wanted are the necessary funds, and the amount
required is but a small fraction of what is annually expended at our
racecourses upon villainous concoctions of carbonic acid and methylated
cider bearing the name of “champagne.”
Arrangements are being made to start next May, but in the meantime many
preliminary experiments are required. One of these, concerning which I
have been boring Commander Cheyne and the committee, is a thorough and
practical trial of the staying properties of hydrogen gas when confined
in given silken or other fabrics saturated with given varnishes. We
are still ignorant on this fundamental point. We know something about
coal-gas, but little or nothing of the hydrogen, such as may be used
in the foregoing expedition. Its exosmosis, as proved by Graham,
depends upon its adhesion to the surface of the substance confining it.
Every gas has its own speciality in this respect, and a membrane that
confines a hydrocarbon like coal-gas may be very unsuitable for pure
hydrogen, or _vice versâ_. Hydrogen passes through hard steel, carbonic
oxide through red-hot iron plates, and so on with other gases. They
are guilty of most improbable proceedings in the matter of penetrating
apparently impenetrable substances.
The safety of the aeronauts and the success of the aerial exploration
primarily depends upon the length of time that the balloons can be kept
afloat in the air.
A sort of humanitarian cry has been raised against this expedition, on
the ground that unnaturally good people (of whom we now meet so many)
should not be guilty of aiding and abetting a scheme that may cause the
sacrifice of human life. These kind friends may be assured that, in
spite of their scruples, the attempt will be made by men who share none
of their fears, unless the preliminary experiments prove that a balloon
cannot be kept up long enough. Therefore the best way to save their
lives is to subscribe _at once_ for the preliminary expense of making
these trials, which will either discover means of traveling safely,
or demonstrate the impossibility of such ballooning altogether. Such
experiments will have considerable scientific value in themselves, and
may solve other problems besides those of arctic exploration.
Why not apply balloons to African exploration or the crossing of
Australia? The only reply to this is that we know too little of the
practical possibilities of such a method of traveling when thus
applied. Hitherto the balloon has only been a sensational toy. We
know well enough that it cannot be steered in a predetermined _line_,
_i.e._, from one _point_ to another given _point_, but this is quite a
different problem from sailing over a given _surface of considerable
area_. This can be done to a certain extent, but we want to know
definitely to what extent, and what are the limits of reliability and
safety. With this knowledge, and its application by the brave and
skillful men who are so eager to start, the solution of the Polar
mystery assumes a new and far more hopeful phase than it has ever
before presented.
THE ANGLO-AMERICAN ARCTIC EXPEDITION.
Commander Cheyne has gone to America to seek the modest equipment
that his own countrymen are unable to supply. He proposes now that
his expedition shall be “Anglo-American.” I have been asked to join
an arctic council, to coöperate on this side, and have refused on
anti-patriotic grounds. As a member of the former arctic committee, I
was so much disgusted with the parsimony of our millionaires and the
anti-geographical conduct of the Savile Row Mutual Admiration Society,
that I heartily wish that in this matter our American grandchildren
may “lick the Britishers quite complete.” It will do us much good.
My views, expressed in the “Gentleman’s Magazine” of July 1880,
and repeated above, remain unchanged, except in the direction of
confirmation and development. I still believe that an enthusiastic,
practically trained, sturdy arctic veteran, who has endured hardship
both at home and abroad, whose craving eagerness to reach the Pole
amounts to a positive monomania, who lives for this object alone, and
is ready to die for it, who will work at it purely for the work’s
sake—will be the right man in the right place when at the head of
a modestly but efficiently equipped Polar expedition, especially if
Lieutenant Schwatka is his second in command.
They will not require luxurious saloons, nor many cases of champagne;
they will care but little for amateur theatricals; they will follow the
naval traditions of the old British “sea-dogs” rather than those of our
modern naval lap-dogs, and will not turn back after a first struggle
with the cruel arctic ice, even though they should suppose it to be
“paleocrystic.”
MR. WALTER POWELL.
Scientific aerostation has lost its most promising expert by the
untimely death of Walter Powell. He was not a mere sensational
ballooner, nor one of those dreamers who imagine they can invent flying
machines, or steer balloons against the wind by mysterious electrical
devices or by mechanical paddles, fan-wheels, or rudders.
He perfectly understood that a balloon is at the mercy of atmospheric
currents and must drift with them, but nevertheless he regarded it as
a most promising instrument for geographical research. I had a long
conference with him on the subject in August last, when he told me that
the main objects of the ascents he had already made, and should be
making for some little time forward, were the acquisition of practical
skill, and of further knowledge of atmospheric currents; after which
he should make a dash at the Atlantic with the intent of crossing to
America.
On my part, I repeated with further argument what I have already urged
on page 113 of the “Gentleman’s Magazine” for July, 1880, viz., the
primary necessity of systematic experimental investigation of the rate
of exosmosis (oozing out) of the gas from balloons made of different
materials and variously varnished.
Professor Graham demonstrated that this molecular permeation of gases
and liquids through membranes mechanically air-tight, depends upon the
adhesive affinities of particular solids for other particular fluids,
and these affinities vary immensely, their variations depending on
chemical differences rather than upon mechanical impermeability. My
project to attach captive balloons of small size to the roof of the
Polytechnic Institution, holding them by a steelyard that should
indicate the pull due to their ascending power, and the rate of its
decline according to the composition of the membrane, was heartily
approved by Mr. Powell, and, had the Polytechnic survived, would
have been carried out, as it would have served the double purpose of
scientific investigation and of sensational advertisement for the
outside public.
If the aeronaut were quite clear on this point—could calculate
accurately how long his balloon would float—he might venture with
deliberate calculation on journeys that without such knowledge are mere
exploits of blind daring.
The varnishes at present used are all permeable by hydrogen gas and
hydrocarbon coal-gas, as might be expected, _à priori_, from the fact
that they are themselves solid hydrocarbons, soluble in other liquid
or gaseous hydrocarbons. Nothing, as far as I can learn, has yet been
done with _silicic or boracic varnishes_,[22] which are theoretically
impermeable by hydrogen and its carbon compounds; but whether they
are practically so under ballooning conditions, and can be made
sufficiently pliable and continuous, are questions only to be solved by
practical experiments of the kind above named. Now that the best man
for making these experiments is gone, somebody else should undertake
them. Unfortunately, they must of necessity be rather expensive.
THE LIMITS OF OUR COAL SUPPLY.[23]
Estimating the actual consumption of coal for home use in Great Britain
at 110 millions of tons per annum, a rise of eight shillings per ton to
consumers is equivalent to a tax of 44 millions per annum. These are
the figures taken by Sir William Armstrong in his address at Newcastle
last February. As the recent abnormal rise in the value of coal has
amounted to more than this, consumers have been paying at some periods
above a million per week as premium on fuel, even after making fair
deduction for the rise of price necessarily due to the diminishing
value of gold.
Are we, the consumers of coal, to write off all this as a dead loss,
or have we gained any immediate or prospective advantage that may be
deducted from the bad side of the account? I suspect that we shall gain
sufficient to ultimately balance the loss, and, even after that, to
leave something on the profit side.
The abundance of our fuel has engendered a shameful wastefulness that
is curiously blind and inconsistent. As a typical example of this
inconsistency, I may mention a characteristic incident. A party of
young people were sitting at supper in the house of a colliery manager.
Among them was the vicar of the parish, a very jovial and genial man,
but most earnest withal in his vocation. Jokes and banterings were
freely flung across the table, and no one enjoyed the fun more heartily
than the vicar; but presently one unwary youth threw a fragment of
bread-crust at his opposite neighbor, and thus provoked retaliation.
The countenance of the vicar suddenly changed, and in stern clerical
tones he rebuked the wickedness of thus wasting the bounties of the
Almighty. A general silence followed, and a general sense of guilt
prevailed among the revellers. At the same time, and in the same room,
a blazing fire, in an ill-constructed open fire-place, was glaring
reproachfully at all the guests, but no one heeded the immeasurably
greater and utterly irreparable waste that was there proceeding. To
every unit of heat that was fully utilized in warming the room, there
were eight or nine passing up the chimney to waste their energies upon
the senseless clouds and boundless outer atmosphere. A large proportion
of the vicar’s parishioners are colliers, in whose cottages huge fires
blaze most wastefully all day, and are left to burn all night to save
the trouble of re-lighting. The vicar diligently visits these cottages,
and freely admonishes where he deems it necessary; yet he sees in this
general waste of coal no corresponding sinfulness to that of wasting
bread. Why is he so blind in one direction, while his moral vision
is so microscopic in the other? Why are nearly all Englishmen and
Englishwomen as inconsistent as the vicar in this respect?
There are doubtless several combining reasons for this, but I
suspect that the principal one is the profound impression which we
have inherited from the experience and traditions of the horrors of
bread-famine. A score of proverbs express the important practical
truth that we rarely appreciate any of our customary blessings until
we have tasted the misery of losing them. Englishmen have tasted the
consequences of approximate exhaustion of the national grain store, but
have never been near to the exhaustion of the national supply of coal.
I therefore maintain most seriously that we need a severe coal famine,
and if all the colliers of the United Kingdom were to combine for a
simultaneous winter strike of about three or six months’ duration,
they might justly be regarded as unconscious patriotic martyrs, like
soldiers slain upon a battle-field. The evils of such a thorough famine
would be very sharp, and proportionally beneficent, but only temporary;
there would not be time enough for manufacturing rivals to sink pits,
and at once erect competing iron-works; but the whole world would
partake of our calamity, and the attention of all mankind would be
aroused to the sinfulness of wasting coal. Six months of compulsory
wood and peat fuel, with total stoppage of iron supplies, would
convince the people of these islands that waste of coal is even more
sinful than waste of bread,—would lead us to reflect on the fact that
our stock of coal is a definite and limited quantity that was placed in
the present storehouse long before human beings came upon the earth;
that every ton of coal that is wasted is lost for ever, and cannot
be replaced by any human effort, while bread is a product of human
industry, and _its_ waste may be replaced by additional human labor;
that the sin of bread-wasting does admit of agricultural atonement,
while there is no form of practical repentance that can positively and
directly replace a hundredweight of wasted coal.
Nothing short of the practical and impressive lesson of bitter want is
likely to drive from our households that wretched fetish of British
adoration, the open “Englishman’s fireside.” Reason seems powerless
against the superstition of this form of fire-worship. Tell one of the
idolaters that his household god is wasteful and extravagant, that
five-sixths of the heat from his coal goes up the chimney, and he
replies, “I don’t care if it does; I can afford to pay for it. I like
to _see_ the fire, and have the right to waste what is my own.” Tell
him that healthful ventilation is impossible while the lower part of
a room opens widely into a heated shaft, that forces currents of cold
air through doors and window leakages, which unite to form a perpetual
chilbrain stratum on the floor, and leaves all above the mantel-piece
comparatively stagnant. Tell him that no such things as “draughts”
should exist in a properly warmed and ventilated house, and that even
with a thermometer at zero outside, every part of a well-ordered
apartment should be equally habitable, instead of merely a semicircle
about the hearth of the fire-worshiper; he shuts his ears, locks up his
understanding, because his grandfather and grandmother believed that
the open-mouthed chimney was the one and only true English means of
ventilation.
But suppose we were to say, “You love a cheerful blaze, can afford to
pay for it, and therefore care not how much coal you waste in obtaining
it. We also love a cheerful blaze, but have a great aversion to
coal-smoke and tarry vapors; and we find that we can make a beautiful
fire, quite inoffensive even in the middle of the room, provided
we feed it with stale quartern loaves. We know that such fuel is
expensive, but can afford to pay for it, and choose to do so.” Would he
not be shocked at the sight of the blazing loaves, if this extravagance
were carried out?
This popular inconsistency of disregarding the waste of a valuable and
necessary commodity, of which the supply is limited and unrenewable,
while we have such proper horror of wilfully wasting another similar
commodity which can be annually replaced as long as man remains in
living contact with the earth, will gradually pass away when rational
attention is directed to the subject. If the recent very mild
suggestion of a coal-famine does something towards placing coal on a
similar pedestal of popular veneration to that which is held by the
“staff of life,” the million a week that it has cost the coal consumer
will have been profitably invested.
Many who were formerly deaf to the exhortations of fuel economists are
now beginning to listen. “_Forty shillings per ton_” has acted like an
incantation upon the spirit of Count Rumford. After an oblivion of more
than eighty years, his practical lessons have again sprung up among us.
Some are already inquiring how he managed to roast 112 lbs. of beef at
the Foundling Hospital with 22 lbs. of coal, and to use the residual
heat for cooking the potatoes, and why it is that with all our boasted
progress we do not now in the latter third of the nineteenth century,
repeat that which he did in the eighteenth.
The fact that the consumption of coal in London during the first four
months of 1873 has, in spite of increasing population, amounted to
49,707 tons less than the corresponding period of 1872, shows that some
feeble attempts have been made to economize the domestic consumption of
fuel. One very useful result of the recent scarcity of coal has been
the awakening of a considerable amount of general interest in the
work of stock-taking, a tedious process which improvident people are
too apt to shirk, but which is quite indispensable to sound business
proceedings, either of individuals or nations.
There are many discrepancies in the estimates that have been made of
the total available quantity of British coal. The speculative nature of
some of the data renders this inevitable, but all authorities appear
to agree on one point, viz., that the amount of our supplies will not
be determined by the actual total quantity of coal under our feet, but
by the possibilities of reaching it. This is doubtless correct, but
how will these possibilities be limited, and what is the extent or
range of the limit? On both these points I venture to disagree with
the eminent men who have so ably discussed this question. First, as
regards the nature of the limit or barrier that will stop our further
progress in coal-getting. This is generally stated to be the depth of
the seams. The Royal Commissioners of 1870 based their tables of the
quantity of available coal in the visible and concealed coal-fields
upon the assumption that 4000 feet is the limit of possible working.
This limit is the same that was taken by Mr. Hull ten years earlier.
Mr. Hull, in the last edition of “The Coal Fields of Great Britain,” p.
326, referring to Professor Ramsay’s estimate, says, “These estimates
are drawn up for depths down to 4000 feet below the surface, and
even beyond this limit; but with this latter quantity it is scarcely
necessary that we should concern ourselves.” I shall presently show
reasons for believing that the time may ultimately arrive when we
_shall_ concern ourselves with this deep coal, and actually get it;
while, on the other hand, that remote epoch will be preceded by another
period of practical approximate exhaustion of British coal supply,
which is likely to arrive long before we reach a working depth of 4000
feet.
The Royal Commissioners estimate that within the limits of 4000
feet we have hundreds of square miles of attainable coal capable of
yielding, after deducting 40 per cent for loss in getting, etc.,
146,480 millions of tons; or, if we take this with Mr. Hull’s deduction
of one-twentieth for seams under two feet in thickness, there remains
139,000 millions of tons, which, at present rate of consumption,
would last about 1200 years. But the rate of consumption is annually
increasing, not merely on account of increasing population, but also
from the fact that mechanical inventions are perpetually superseding
hand labor, and the source of power in such cases, is usually derived
from coal. This consideration induced Professor Jevons, in 1865, to
estimate that between 1861 and 1871 the consumption would increase from
83,500,000 tons to 118,000,000 tons. Mr. Hunt’s official return for
1871 shows that this estimate was a close approximation to the truth,
the actual total for 1871 having been 117,352,028 tons. At this rate of
an arithmetical increase of three and a half tons per annum, 139,000
millions of tons would last but 250 years. Mr. Hull, taking the actual
increase at three millions of tons per annum, extends it to 276 years.
Hitherto the annual increase has followed a geometrical, rather than
arithmetical progress, and those who anticipate a continuance of this
allow us a much shorter lease of our coal treasures. Mr. Price Williams
maintains that the increase will proceed in a diminishing ratio
like that of the increase of population; and upon this basis he has
calculated that the annual consumption will amount to 274 millions of
tons a hundred years hence, and the whole available stock of coal will
last about 360 years.
The latest returns show, for 1872, an output of 123,546,758 tons,
which, compared with 1871, gives a rate of increase of more than double
the estimate of Mr. Hull, and indicate that prices have not yet risen
sufficiently to check the geometrical rate of increase.[24] Mr Hull
very justly points out the omission in those estimates which do not
“take into account the diminishing ratio at which coal must be consumed
when it becomes scarcer and more expensive;” but, on the other hand,
he omits the opposite influence of increasing prices on production,
which has been strikingly illustrated by the extraordinary number of
new coal-mining enterprises that have been launched during the last
six months. If we continue as we are now proceeding, a practical and
permanent coal famine will be upon us within the lifetime of many of
the present generation. By such a famine, I do not mean an actual
exhaustion of our coal seams (which will never be effected), but such
a scarcity and rise of prices as shall annihilate the most voracious
of our coal-consuming industries, those which depend upon abundance of
cheap coal, such as the manufacture of pig-iron, etc.[25]
The action of increasing prices has been but lightly considered
hitherto, though its importance is paramount in determining the limits
of our coal supply; I even venture so far as to affirm that it is
not the depth of the coal seams, not the increasing temperature nor
pressure as we proceed downwards, nor even thinness of seam, that will
practically determine the limits of British coal-getting, but simply
the price per ton at the pit’s mouth.
In proof of this, I may appeal to actual practice. Mr. Hull and others
have estimated the working limit of thinness at two feet, and agree in
regarding thinner seams than this as unworkable. This is unquestionably
correct so long as the getting is effected in the usual manner. A
collier cannot lie down and hew a much thinner seam than this, if he
works as colliers work at present. But the lead and copper miners
succeed in working far thinner lodes, even down to the thickness of a
few inches, and the gold-digger crushes the hardest component of the
earth’s crust to obtain barely visible grains of the precious metal.
This extension of effort is entirely determined by market value. At
a sufficiently high price the two-feet limit of coal-getting would
vanish, and the collier would work after the manner of the lead-miner.
We may safely apply the same reasoning to the limits of depth. The 4000
feet limit of the Royal Commissioners is _at present_ unattainable,
simply because the immediately prospective price of coal would not
cover the cost of such deep sinking and working; but as prices go up,
pits will go down, deeper and deeper still.
The obstacles which are assumed to determine the 4000 feet limit
are increasing density due to greater pressure, and the elevation
of temperature which proceeds as we go downwards. The first of
these difficulties has, I suspect, been very much overstated, if
not altogether misunderstood; though it is but fair to add that Mr.
Hull, who most prominently dwells upon it, does so with all just
and philosophic caution. He says that “it is impossible to speak
with certainty of the effect of the accumulative weight of 3000 or
4000 feet of strata on mining operations. In all probability one
effect would be to increase the density of the coal itself, and
of its accompanying strata, so as to increase the difficulty of
excavating,” and he concludes by stating that “in the face of these
two obstacles—temperature and pressure, ever increasing with the
depth—I have considered it utopian to include in calculations having
reference to coal supply any quantity, however considerable, which lies
at a greater depth than 4000 feet. Beyond that depth I do not believe
that it will be found practicable to penetrate. Nature rises up, and
presents insurmountable barriers.”[26]
On one point I differ entirely from Mr. Hull, viz., the conclusion
that the increased “density of the coal itself and of its accompanying
strata” will offer any serious obstacle. On the contrary, there is good
reason to believe that such density is one of the essential conditions
for working deep coal. Even at present depths of working, density and
hardness of the accompanying strata is one of the most important aids
to easy and cheap coal-getting. With a dense roof and floor the collier
works vigorously and fearlessly, and he escapes the serious cost of
timbering.
Those who have never been underground, and only read of colliery
disasters, commonly regard the fire-damp and choke-damp as the
collier’s most deadly enemies, but the collier himself has quite as
much dread of a rotten roof as of either of these: he knows by sad
experience how much bruising, and maiming, and crushing of human limbs
are due to the friability of the rock above his head. Mr. Hull quotes
the case of the Dunkinfield colliery, where, at a depth of about 2500
feet, the pressure is “so resistless as to crush in circular arches of
brick four feet thick,” and to snap a cast-iron pillar in twain; but he
does not give any account of the density of the accompanying strata at
the place of these occurrences. I suspect that it was simply _a want of
density_ that allowed the superincumbent pressure to do such mischief.
The circular arches of brick four feet thick were but poor substitutes
for a roof of solid rock of 40 or 400 feet in thickness; an arch cut
in such a rock would be all key-stone: and I may safely venture to
affirm that if, in the deep sinkings of the future, we do encounter the
increased density which Mr. Hull anticipates, this will be altogether
advantageous. I fear, however, that it will not be so, that the chief
difficulty of deep coal-mining will arise from occasional “running
in” due to deficient density, and that this difficulty will occur in
about the same proportion of cases as at present, but will operate more
seriously at the greater depths.
A very interesting subject for investigation is hereby suggested.
Do rocks of given composition and formation increase in density as
they dip downwards; and if so, does this increase of density follow
any law by which we may determine whether their power of resisting
superincumbent pressure increases in any approach to the ratio of the
increasing pressure to which they are naturally subjected? If the
increasing density and power of resistance reaches or exceeds this
ratio, deep mining has nothing to fear from pressure. If they fall
short of it, the difficulties arising from pressure may be serious.
Friability, viscosity, and power of resisting a crushing strain must be
considered in reference to this question.
Mr. Hull has collected a considerable amount of data bearing upon
the rate of increase of temperature with depth. His conclusions give
a greater rate of increase than is generally stated by geologists;
but for the present argument I will accept, without prejudice, as the
lawyers say, his basis of a range of 1° F. for 60 feet. According
to this, the _rocks_ will reach 99.6°, a little above blood-heat,
at 3000 feet, and 116.3° at the supposed limit of 4000 feet. It is
assumed by Mr. Hull, by the Commissioners, and most other authorities,
that this rock temperature of 116° will limit the possibilities of
coal-mining. At the average prices of the last three years, or the
prospective prices of the next three years, this temperature may be,
like difficulties of the thin seams, an insurmountable barrier; but I
contend that at higher prices we may work coal at this, and even far
higher, rock temperatures; that it matters not how high the thermometer
rises as we descend, we shall still go lower and still get coal so long
as prices rise with the mercury. Given this condition, and I have no
doubt that coal may be worked where the rock temperature shall reach or
even exceed 212°. I do not say that we shall actually work coal at such
depths; but if we do not, the reason will be, not that the thermometer
is too high, but that prices are too low; in other words, value, not
temperature, will determine the working limits.
Mr. Leifchild, in the last number of the “Edinburgh Review,” in
discussing this question, tells us that “the normal heat of our blood
is 98°, and fever heat commences at 100°, and the extreme limit of
fever heat may be taken at 112°. Dr. Thudichum, a physician who has
specially investigated this subject, has concluded from experiments
on his own body at high temperatures, that at a heat of 140° no work
whatever could be carried on, and that at a temperature of from 130°
to 140° only a very small amount of labor, and that at short periods,
was practicable; and further, that human labor daily, and at ordinary
periods, is limited by 100° of temperature, as a fixed point, and then
the air must be dry, for in moist air he did not think men could endure
ordinary labor at a temperature exceeding 90°.”
It may be presumptuous on my part to dispute the conclusions of a
physician on such a subject, but I do so nevertheless, as the data
required are simple practical facts such as are better obtained by
furnace-working than by sick-room experience.
During the hottest days of the summer of 1868 I was engaged in making
some experiments in the re-heating furnaces at Sir John Brown & Co.’s
works, Sheffield, and carried a thermometer about with me which I
suspended in various places where the men were working. At the place
where I was chiefly engaged (a corner between two sets of furnaces),
the thermometer, suspended in a position where it was not affected
by direct radiations from the open furnaces, stood at 120° while the
furnace doors were shut. The _radiant_ heat to which the men themselves
were exposed while making their greatest efforts in placing and
removing the piles was far higher than this, but I cannot state it, not
having placed the thermometer in the position of the men. In one of
the Bessemer pits the thermometer reached 140°, and men worked there
at a kind of labor demanding great muscular effort. It is true that
during this same week the puddlers were compelled to leave their work;
but the tremendous amount of concentrated exertion demanded of the
puddler in front of a furnace, which, during the time of removing the
balls, radiates a degree of heat quite sufficient to roast a sirloin
of beef if placed in the position of the puddles hands, is beyond
comparison with that which would be demanded of a collier working even
at a depth giving a theoretical rock temperature of 212°, and aided
by the coal-cutting and other machinery that sufficiently high prices
would readily command. In some of the operations of glass-making, the
ordinary summer working temperature is considerably above 100°, and
the radiant neat to which the workmen are subjected far exceeds 212°.
This is the case during a “pot setting,” and in the ordinary work of
flashing crown glass.
As regards the mere endurance of a high temperature, the well-known
experiments of Blagden, Sir Joseph Banks, and others have shown that
the human body can endure for short periods a temperature of 260°
F., and upwards. My own experience of furnace-work, and of Turkish
baths, quite satisfies me that I could do a fair day’s work of six
or eight hours in a temperature of 130° F., provided I were free from
the encumbrances of clothing, and had access to abundance of tepid
water. This in a still atmosphere; but with a moving current of dry
air capable of promoting vigorous evaporation from the skin, I suspect
that the temperature might be ten or fifteen degrees higher. I _enjoy_
ordinary walking exercise in a well-ventilated Turkish bath at 150°,
and can endure it at 180°.
In order to obtain further information on this point, I have written to
Mr. Tyndall, the proprietor of the Turkish baths at Newington Butts. He
is an architect, who has had considerable experience in the employment
of workmen and in the construction of Turkish baths and other hot-air
chambers. He says: “Shampooers work in my establishment from four to
five hours at a time _in a moist atmosphere_ at a temperature ranging
from 105° to 110°. I have myself worked twenty hours out of twenty-four
in one day in a temperature over 110°. Once for one half-hour I
shampooed in 185°. At the enamel works in Pimlico, belonging to Mr.
Mackenzie, men work daily in a heat of over 300°. The moment a man
working in a 110° heat begins to drink alcohol, his tongue gets
parched, and he is obliged to continue drinking while at work, and the
brain gets so excited that he cannot do half the amount. I painted my
skylights, taking me about four hours, at a temperature of about 145°;
also the hottest room skylights, which took me one hour, coming out
at intervals for “a cooler,” at a temperature of 180°. I may add in
conclusion, that a man can work well in a moist temperature of 110° if
he perspires freely.”
The following, by a writer whose testimony may be safely accepted, is
extracted from an account of ordinary passenger ships of the Red Sea,
in the “Illustrated News,” of November 9, 1872: “The temperature in
the stoke-hole was 145°. The floor of this warm region is close to
the ship’s keel, so it is very far below. There are twelve boilers,
six on each side, each with a blazing furnace, which has to be opened
at regular intervals to put in new coals, or to be poked up with long
iron rods. This is the duty of the poor wretches who are doomed to
this work. It is hard to believe that human beings could be got to
labor under such conditions, yet such persons are to be found. The work
of stoking or feeding the fires is usually done by Arabs, while the
work of bringing the coal from the bunkers is done by sidi-wallahs or
negroes. At times some of the more intelligent of these _are promoted
to the stoking_. The negroes who do this kind of work come from
Zanzibar. They are generally short men, with strong limbs, round bullet
heads, and the very best of good nature in their dispositions. Some of
them will work half an hour in such a place as the stoke-hole without
a drop of perspiration on their dark skins. Others, particularly the
Arabs, when it is so hot as it often is in the Red Sea, have to be
carried up in a fainting condition, and are restored to animation by
dashing buckets of water over them as they lie on deck.”
It must be remembered that the theoretical temperature of 116° at
4000 feet, the 133° at 5000 feet, or the 150° at 6000 feet, are
the temperatures of _the undisturbed rock_; that this rock is a
bad conductor of heat, whose surface may be considerably cooled by
radiation and convection; and therefore we are by no means to regard
the rock temperature as that of the air of the roads and workings
of the deep coal-pits of the future.[27] It is true that the Royal
Commissioners have collected many facts showing that the actual
difference between the face of the rocks of certain pits and the air
passing through them is but small; but these data are not directly
applicable to the question under consideration for the three following
reasons:
_First._ The comparisons are made between the temperature of the
air and the actual temperature of the opened and already cooled
strata, while the question to be solved is the difference between the
theoretical temperature of the unopened earth depths and that of the
air in roads and working’s to be opened through them.
_Second._ The cooling effect of ventilation must (as the Commissioners
themselves state) increase in a ratio which “somewhat exceeds the ratio
of the difference between the temperature of the air and that of the
surrounding surface with which it is in contact.” Thus, the lower we
proceed the more and more effectively cooling must a given amount of
ventilation become.
The third, and by far the most important, reason is, that in the deep
mining of the future, special means will be devised and applied to
the purpose of lowering the temperature of the workings; that as the
descending efforts of the collier increase with the ascending value of
the coal, a new problem will be offered for solution, and the method of
working coal will be altered accordingly. In the cases quoted by the
Commissioners, the few degrees of cooling were effected by a system of
ventilation that was devised to meet the requirements of respiration,
and not for the purpose of cooling the mine.
It would be very presumptuous for anyone in 1873 to say how this
special cooling will actually be effected, but I will nevertheless
venture to indicate one or two principles which may be applied to the
solution of the problem. First of all, it must be noted that very deep
mines are usually dry; and there is good reason to believe that, before
reaching the Commissioners’ limit of 4000 feet, dry mining would be the
common, and at and below 4000 feet the universal, case. At present we
usually obtain coal from water-bearing strata, and all our arrangements
are governed by this very serious contingency. With water removed, the
whole system of coal-mining may be revolutionized, and thus the aspect
of this problem of cooling the workings would become totally changed.
Those who are acquainted with the present practice of mining are aware
that when an estate is taken, and about to be worked for coal, the
first question to be decided is the dip of the measures, in order that
the sinking may be made “on the deep” of the whole range. The pits are
not sunk at that part of the same range where, at first sight, the coal
appears the most accessible, but, on the contrary, at the deepest part.
It is then carried on to some depth below the coal seam which is to be
worked, in order to form a “sumpf” or receptacle from which the water
may be wound or pumped. The necessity for this in water-bearing strata
is obvious enough. If the collier began at the shallowest portion of
his range, and attempted to proceed downwards, he would be “drowned
out” unless he worked as a coal-diver rather than a coal-miner. By
sinking in the deep he works upwards, away from the water, which all
drains down to the sumpf, from which it is pumped.
The modern practice is to sink “a pair of pits,” _both on the deep_,
and within a short distance of each other. The object of the second is
ventilation. By contrivances, which I need not here detail, the air is
made to descend one of the pits, “the downcast shaft,” then to traverse
the roads and workings wherein ventilation is required, and return by a
reverse route to the “upcast shaft,” by which it ascends to the surface.
Thus it will be seen that, whenever the temperature of the roads and
workings exceeds that of the outer atmosphere; the air currents have to
be forced to travel through the mine in a direction contrary to their
natural course. The cooler air of the downcast shaft has to climb the
inclined roads, and then after attaining its maximum temperature in
the fresh workings must _descend_ the roads till it reaches the upcast
shaft. The cool air must rise and the warmer air descend.
What, then, would be the course of the mining engineer when all
the existing difficulties presented by water-bearing strata should
be removed, and their place taken by a new and totally different
obstacle, viz., high temperature? Obviously to reverse the present
mode of working—to sink on the upper part of the range and drive
downwards. In such a system of working the ventilation of the pit will
be most powerfully aided or altogether effected by natural atmospheric
currents. An upcast once determined by artificial means, it will
thereafter proceed spontaneously, as the cold air of the downcast
shaft will travel by a descending road to the workings, and then after
becoming heated will simply obey the superior pressure of the heavy
column behind, and proceed by an upward road to the upcast shaft. As
the impelling force of the air current will be the difference between
the weight of the cool column of air in the downcast shaft and roads
and the warm column in the upcast, the available force of natural
ventilation and cooling will increase just as demanded, _i.e._, it
will increase with the depth of the workings and the heat of the
rocks. A mining engineer who knows what is actually done with present
arrangements, will see at once that with the above-stated advantages
a gale of wind or even a hurricane might be directed through any
particular roads or long-wall workings that were once opened. Let us
suppose the depth to be 5000 feet, the rock temperature at starting
133°, and that of the outer air 60°, we should have a torrent of air,
73° cooler than the rocks, rushing furiously downwards, then past the
face of the heated strata, and absorbing its heat to such an extent
that the upcast shaft would pour forth a perpetual blast of hot air
like a gigantic furnace chimney.
But this is not all; the heat and dryness of these deep workings of the
future place at our disposal another and still more efficient cooling
agency than even that of a hurricane of dry-air ventilation. In the
first part of the sinking of the deep shafts the usual water-bearing
strata would be encountered, and the ordinary means of “tubbing” or
“coffering” would probably be adopted for temporary convenience during
sinking. Doorways, however, would be left in the tubbing at suitable
places for tapping at pleasure the wettest and most porous of the
strata. Streams of cold water could thus be poured down the sides of
the shaft, which, on reaching the bottom, would flow by a downhill road
into the workings. The stream of air rushing by the same route and
becoming heated in its course would powerfully assist the evaporation
of the water. The deeper and hotter the pit, the more powerful would be
these cooling agencies.
As the specific heat of water is about five times that of the
coal-measure rocks, or the coal itself, every degree of heat
communicated to each pound of water would abstract one degree from five
pounds of rocks. But in the conversion of water at 60° into vapor at
say 100°, the amount of heat absorbed is equivalent to that required
to raise the same weight of water about 1000°, and thus the effective
cooling power on the rock would be equivalent to 5000°.
The workings once opened (I assume as a matter of course that by this
time pillar-and-stall working will be entirely abandoned for long-wall
or something better), there would be no difficulty in thus pouring
streams of water and torrents of air through the workings during the
night, or at any suitable time preparatory to the operations of the
miner, who long before the era of such deep workings will be merely the
director of coal-cutting and loading machinery.
Given a sufficiently high price for coal at the pit’s mouth to pay
wages and supply the necessary fixed capital, I see no insuperable
difficulty, _so far as mere temperature is concerned_, in working coal
at double the depth of the Royal Commissioners’ limit of possibility.
At such a depth of 8000 feet the theoretical rock-temperature is 183°.
By the means above indicated, I have no doubt that this could be
reduced to an _air_ temperature below 110°—that at which Mr.
Tyndall’s shampooers ordinarily work. Of course the newly-exposed
face of the coal would have its initial temperature of 183°; but this
is a trivial heat compared to the red-hot radiant surfaces to which
puddlers, shinglers, glassmakers, etc., are commonly exposed. Divested
of the incumbrance of clothing, with the whole surface of the skin
continuously fanned by a powerful stream of air—which, during working
hours need be but partly saturated with vapor—a sturdy midland or
north-countryman would work merrily enough at short hours and high
wages, even though the newly-exposed face of coal reached 212°; for
we must remember that this new coal-face would only correspond to
the incomparably hotter furnace-doors and fires of the steamship
stoke-holes.
The high temperature at 8000 or even 10,000 feet would present a really
serious difficulty during the first opening of communications between
the two pits. A spurt of brave effort would here be necessary, and if
anybody doubts whether Englishmen could be found to make the effort,
let him witness a “pot-setting” at a glass-house. Negro labor might be
obtained if required, but my experience among English workmen leads me
to believe that they will never allow negroes or any others to beat
them at home in any kind of work where the wages paid are proportionate
to the effort demanded.
If I am right in the above estimates of working possibilities, our coal
resources may be increased by about forty thousand millions of tons
beyond the estimate of the Commissioners. To obtain such an additional
quantity will certainly be worth an effort, and unless we suffer a far
worse calamity than the loss of all our minerals, viz., a deterioration
of British energy, the effort will assuredly be made.
I have said repeatedly that it is not physical difficulties but market
value that will determine the limits of our coal-mining. This, like
all other values, is of course determined by the relation between
demand and supply. Fuel being one of the absolute necessaries of life,
the demand for it must continue so long as the conditions of human
existence remain as at present, and the outer limits of the possible
value of coal will be determined by that of the next cheapest kind of
fuel which is capable of superseding it.
We begin by working the best and most accessible seams, and while those
remain in abundance the average value of coal will be determined by the
cost of producing it under these easy conditions. Directly these most
accessible seams cease to supply the whole demand, the market value
rises until it becomes sufficient to cover the cost of working the less
accessible; and the average value will be regulated not by the cost of
working what remains of the first or easy mines, but by that of working
the most difficult that must be worked in order to meet the demand.
This is a simple case falling under the well-established economic law,
that the natural or cost value of any commodity is determined by the
cost value of the most costly portion of it. Thus, the only condition
under which we can proceed to sink deeper and deeper, is a demand of
sufficient energy to keep pace with the continually increasing cost
of production. This condition can only be fulfilled when there is no
competing source of cheaper production which is adequate to supply the
demand.
The question then resolves itself into this: Is any source of supply
likely to intervene that will prevent the value of coal from rising
sufficiently to cover the cost of working the coal seams of 4000 feet
and greater depth? Without entering upon the question of peat and
wood fuel, both of which will for some uses undoubtedly come into
competition with British coal as it rises in value, I believe that
there are sound reasons for concluding that our London fireplaces,
and those of other towns situated on the sea-coast and the banks of
navigable rivers, will be supplied with transatlantic coal long before
we reach the Commissioner’s limit of 4000 feet. The highest prices of
last winter, if steadily maintained, would be sufficient to bring about
this important change. Temporary upward jerks of the price of coal have
very little immediate effect upon supply, as the surveying, conveyance,
boring, sinking, and fully opening of a new coal estate is a work of
some years.
The Royal Commissioners estimate that the North-American coal-fields
contain an untouched coal area equal to seventy times the whole of
ours. Further investigation is likely to increase rather than diminish
this estimate. An important portion of this vast source of supply is
well situated for shipment, and may be easily worked at little cost.
Hitherto, the American coal-fields have been greatly neglected, partly
on account of the temptations to agricultural occupation which are
afforded by the vast area of the American continent, and partly by
the barbarous barriers of American politics. Large amounts of capital
which, under the social operation of the laws of natural selection,
would have been devoted to the unfolding of the vast mineral resources
of the United States, are still wastefully invested in the maintenance
of protectively nursed and sickly imitation of English manufactures.
When the political civilization of the United States become
sufficiently advanced to establish a national free-trade policy, this
perverted capital will flow into its natural channels, and the citizens
of the States will be supplied with the more highly elaborated
industrial products at a cheaper rate than at present, by obtaining
them in exchange for their superabundant raw material from those
European countries where population is overflowing the raw material
supplies.
When this time arrives, and it may come with the characteristic
suddenness of American changes, the question of American _versus_
English coal in the English markets will reduce itself to one of
horizontal _versus_ vertical difficulties. If at some future period the
average depth of the Newcastle coal-pits becomes 3000 feet greater than
those of the pits near the coast of the Atlantic or American lakes, and
if the horizontal difficulties of 3000 miles of distance are less than
the vertical difficulties of 3000 feet of depth, then coals will be
carried from America to Newcastle. They will reach London and the towns
on the South Coast before this, that is, when the vertical difficulties
at Newcastle plus those of horizontal traction from Newcastle to the
south, exceed those of eastward traction across the Atlantic.
As the cost of carriage increases in a far smaller ratio than the
open ocean distance, there is good reason for concluding that the
day when London houses will be warmed by American coal is not very
far distant. We, in England, who have outgrown the pernicious folly
of “protecting native industry” will heartily welcome so desirable a
consummation. It will render unnecessary any further inquiry into the
existence of London “coal rings” or combinations for restricted output
among colliers or their employers. If any morbid impediments to the
free action of the coal trade do exist, the stimulating and purgative
influence of foreign competition will rapidly restore the trade to a
healthy condition.
The effect of such introduction of American coal will not be to
perpetually lock up our deep coal nor even to stop our gradual progress
towards it. We shall merely proceed downwards at a much slower rate,
for in America, as with ourselves, the easily accessible coal will be
first worked, and as that becomes exhausted, the deeper, more remote,
thinner, and inferior will only remain to be worked at continually
increasing cost. When both our own and foreign coal cost more than
peat, or wood, or other fuel, then and therefore will coal become quite
inaccessible to us, and this will probably be the case long before
we are stopped by the physical obstacles of depth, density, or high
temperature.
As this rise of value must of necessity be gradual, and as the
superseding of British by foreign coal, as well as the final disuse
of coal, will gradually converge from the circumference towards the
centres of supply, from places distant from coal-pits to those close
around them, we shall have ample warning and opportunity for preparing
for the social changes that the loss of the raw material will enforce.
The above-quoted writer, in the “Edinburgh Review,” expresses in
strong and unqualified terms an idea that is very prevalent in England
and abroad: he says that, “The course of manufacturing supremacy of
wealth and of power is directed by coal. That wonderful mineral, of
the possession of which Englishmen have thought so little but wasted
so much, is the modern realization of the philosopher’s stone. This
chemical result of primeval vegetation has been the means by its
abundance of raising this country to an unprecedented height of
prosperity, and its deficiency might have the effect of lowering it to
slow decline.”
*** “It raises up one people and casts down another; it makes railways
on land and paths on the sea. It founds cities, it rules nations, it
changes the course of empires.”
The fallacy of these customary attributions of social potency to mere
mineral matter is amply shown by facts that are previously stated by
the reviewer himself. He tells us that “the coal-fields of China extend
over an area of 400,000 square miles; and a good geologist, Baron Von
Richthofen, has reported that he himself has found a coal-field in
the province of Hunau covering an area of 21,700 square miles, which
is nearly double our British coal area of 12,000 square miles. In the
province of Shansi, the Baron discovered nearly 30,000 square miles
of coal with unrivaled facilities for mining. But all these vast
coal-fields, capable of supplying the whole world for some thousands of
years to come, are lying unworked.”
If “the course of manufacturing supremacy of wealth and of power” were
directed by coal, then China, which possesses 33·3 times more of this
directive force than Great Britain, and had so early a start in life,
should be the supreme summit of the industrial world. If this solid
hydrocarbon “raises up one people and casts down another,” the Chinaman
should, be raised thirty-three times and three tenths higher than the
Englishman; if it “makes railways on land and paths on the sea,” the
Chinese railways should be 33·3 times longer than ours, and the tonnage
of their mercantile marine 33·3 times greater.
Every addition to our knowledge of the mineral resources of other parts
of the world carries us nearer and nearer to the conclusion that the
old idea of the superlative abundance of the natural mineral resources
of England is a delusion. We are gradually discovering that, with the
one exception of tin-stone, we have but little if any more than an
average supply of useful ores and mineral fuel. It is a curious fact,
and one upon which we may profitably ponder, that the poorest and the
worst iron ores that have ever been commercially reduced, are those of
South Staffordshire and the Cleveland district, and these are the two
greatest iron-making centres of the world. There are no ores of copper,
zinc, tin, nickel, or silver in the neighborhood of Birmingham, nor any
golden sands upon the banks of the Rea, yet this town is the hardware
metropolis of the world, the fatherland of gilding and plating, and is
rapidly becoming supreme in the highest art of gold and silver work.
These, and a multitude of other analogous facts, abundantly refute the
idea that the native minerals, the natural fertility, the navigable
rivers, or the convenient seaports, determine the industrial and
commercial supremacy of nations. The moral forces exerted by the
individual human molecules are the true components which determine
the resulting force and direction of national progress. It is the
industry and skill of our workmen, the self-denial, the enterprise,
and organizing ability of our capitalists, that has brought our coal
so precociously to the surface and redirected for human advantage the
buried energies of ancient sunbeams, while the fossil fuel of other
lands has remained inert.
The foreigner who would see a sample of the source of British
prosperity must not seek for it in a geological museum or among our
subterranean rocks; let him rather stand on the Surrey side of London
Bridge from 8 to 10 A.M. and contemplate the march of one of the
battalions of our metropolitan industrial army, as it pours forth in
an unceasing stream from the railway stations towards the City. An
analysis of the moral forces which produce the earnest faces and rapid
steps of these rank and file and officers of commerce will reveal
the true elements of British greatness, rather than any laboratory
dissection of our coal or ironstone.
Fuel and steam-power have been urgently required by all mankind.
Englishmen supplied these wants. Their urgency was primary and they
were first supplied, even though the bowels of the earth had to be
penetrated in order to obtain them. In the present exceptional and
precocious degree of exhaustion of our coal treasures, we have the
_effect_ not the _cause_ of British industrial success.
If in a ruder age our greater industrial energy enabled us to take
the lead in supplying the ruder demands of our fellow-creatures, why
should not a higher culture of those same abundant energies qualify us
to maintain our position and enable us to minister to the more refined
and elaborate wants of a higher civilization? There are other necessary
occupations quite as desirable as coal-digging, furnace-feeding, and
cotton-spinning.
The approaching exhaustion of our coal supplies should therefore serve
us as a warning for preparation. Britain will be forced to retire from
the coal trade, and should accordingly prepare her sons for higher
branches of business,—for those in which scientific knowledge and
artistic training will replace mere muscular strength and mechanical
skill. We have attained our present material prosperity mainly by our
excellence in the use of steam-power; let us now struggle for supremacy
in the practical application of brain-power.
We have time and opportunity for this. The exhaustion of our coal
supplies will go on at a continually retarding pace—we shall always
be approaching the end, but shall never absolutely reach it, as every
step of approximation will diminish the rate of approach; like the
everlasting process of reaching a given point by continually halving
our distance from it.
First of all we shall cease to export coal; then we shall throw up
the most voracious of our coal-consuming industries, such as the
reduction of iron-ore in the blast-furnace; then copper-smelting and
the manufacture of malleable iron and steel from the pig, and so on
progressively. If we keep in view the natural course and order of
such progress, and intelligently prepare for it, the loss of our coal
need not in the smallest degree retard the progress of our national
prosperity.
If, however, we act upon the belief that the advancement of a nation
depends upon the mere accident of physical advantages, if we fold our
arms and wait for Providence to supply us with a physical substitute
for coal, we shall become Chinamen, minus the unworked coal of China.
If our educational efforts are conducted after the Chinese model; if we
stultify the vigor and freshness of young brains by the weary, dull,
and useless cramming of words and phrases; if we poison and pervert
the growing intellect of British youth by feeding it upon the decayed
carcases of dead languages, and on effete and musty literature, our
progress will be proportionately Chinaward; but if we shake off that
monkish inheritance which leads so many of us blindly to believe that
the business of education is to produce scholars rather than men, and
direct our educational efforts towards the requirements of the future
rather than by the traditions of the past, we need have no fear that
Great Britain will decline with the exhaustion of her coal-fields.
The teaching and training in schools and colleges must be directly and
designedly preparatory to those of the workshop, the warehouse, and the
office; for if our progress is to be worthy of our beginning, the moral
and intellectual dignity of industry must be formally acknowledged
and systematically sustained and advanced. Hitherto, we have been the
first and the foremost in utilizing the fossil forces which the miner
has unearthed; hereafter we must in like manner avail ourselves of
the living forces the philosopher has revealed. Science must become
as familiar among all classes of Englishmen as their household fuel.
The youth of England must be trained to observe, generalize, and
_investigate_ the phenomena and forces of the world outside themselves;
and also those moral forces within themselves, upon the right or wrong
government of which the success or failure, the happiness or misery of
their lives will depend.
With such teaching and training the future generations of England will
make the best and most economical use of their coal while it lasts, and
will still advance in material and moral prosperity in spite of its
progressive exhaustion.
“THE ENGLISHMAN’S FIRESIDE.”
During the investment of Paris, the _Comptes Rendus_ of the Acadamy
of Sciences were mainly filled with papers on the construction and
guidance of balloons; with the results of ingenious researches on
methods of making milk and butter without the aid of cows; on the
extraction of nutritious food from old boots, saddles, and other
organic refuse; and other devices for rendering the general famine more
endurable. In like manner, our present coal famine is directing an
important amount of scientific, as well as commercial, attention to the
subject of economizing coal and finding substitutes for it.
A few thoughtful men have shocked their fellow-sufferers very
outrageously by wishing that coal may reach 3_l._ per ton, and remain
at that price for a year or two. I confess that, in spite of my own
empty coal-cellar and small income, I am one of those hard-hearted cool
calculators, being confident that, even from the narrow point of view
of my own outlay in fuel, the additional amount I should thus pay in
the meantime would be a good investment, affording by an ample return
in the saving due to consequent future cheapness.
Regarded from a national point of view, I am convinced that 3_l._ a
ton in London, and corresponding prices in other districts, if thus
maintained, would be an immense national blessing. I say this, being
convinced that nothing short of pecuniary pains and penalties of
ruinous severity will stir the blind prejudices of Englishmen, and
force them to desist from their present stupid and sinful waste of the
greatest mineral treasure of the island.
One of the grossest of our national manifestations of Conservative
stupidity is our senseless idolatrous worship of that domestic fetish,
“the Englishman’s fireside.” We sacrifice health, we sacrifice comfort,
we begrime our towns and all they contain with sooty foulness, we
expend an amount far exceeding the interest of the national debt,
and discount our future prospects of national prosperity, in order
that we may do what? Enjoy the favorite recreation of idiots. It is a
well-known physiological fact that an absolute idiot, with a cranium
measuring sixteen inches in circumference, will sit and stare at a
blazing fire for hours and hours continuously, all the day long, except
when feeding, and that this propensity varies with the degree of mental
vacuity.
Few sights are more melancholy than the contemplation of a party
of English fire-worshipers seated in a semicircle round the family
fetish on a keen frosty day. They huddle together, roast their knees,
and grill their faces, in order to escape the chilling blast that is
brought in from all the chinks of leaky doors and windows by the very
agent they employ, at so much cost, for the purpose of keeping the cold
away. The bigger the fire the greater the draught, the hotter their
faces the colder their backs, the greater the consumption of coal the
more abundant the crop of chilblains, rheumatism, catarrh, and other
well-deserved miseries.
The most ridiculous element of such an exhibition is the complacent
self-delusion of the victims. They believe that their idol bestows upon
them an amount of comfort unknown to other people, that it affords
the most perfect and salubrious ventilation, and, above all, that it
is a “cheerful” institution. The “cheerfulness” is, perhaps, the
broadest part of the whole caricature, especially when we consider
that, according to this theory of the cheerfulness of fire-gazing, the
16-inch idiot must be the most cheerful of all human beings.
The notion that our common fireplaces and chimneys afford an efficient
means of ventilation, is almost too absurd for serious discussion.
Everybody who has thought at all on the subject is aware that in
cold weather the exhalations of the skin and lungs, the products of
gas-burning, etc., are so much heated when given off that they rise
to the upper part of the room (especially if any cold outer air is
admitted), and should be removed from there before they cool again and
descend. Now, our fireplace openings are just where they ought _not_ to
be for ventilation; they are at the lower part of the room, and thus
their action consists in creating a current of cold air or “draught”
from doors and windows, which cold current at once descends, and then
runs along the floor, chilling our toes and provoking chilblains.
This cold fresh air having done its worst in the way of making us
uncomfortable, passes directly up the chimney without doing us any
service for purposes of respiration. Our mouths are usually above the
level of the chimney opening, and thus we only breathe the vitiated
atmosphere which it fails to remove.
Not only does the fire-opening fail to purify the air we breathe, it
actually prevents the leakage of the lower part of the windows and
doors from assisting in the removal of the upper stratum of vitiated
air, for the strong up-draught of the chimney causes these openings
to be fully occupied by an inflowing current of cold air, which at
once descends, and then proceeds, as before stated, to the chimney.
If the leakage is insufficient to supply the necessary amount of
chilblain-making and bronchitis-producing draught, it has to enter
by way of the chimney-pot in the form of occasional spasms of
down-draught, accompanied by gusts of choking and blackening smoke. It
is a fact not generally known, that smoky chimneys are especial English
institutions, one of the peculiar manifestations of our very superior
domestic comfortableness.
It is true that, in some of our rooms, an Arnott’s ventilator opens
into the upper part of the chimney, but this was intended by Dr.
Arnott as an adjunct to his modification of the German stove, and such
ventilator can only act efficiently where a stove is used. The pressure
required to fairly open it can only be regularly obtained when the
chimney is closed below, or its lower opening is limited to that of a
stovepipe.
The mention of a German stove has upon an English fire-worshiper a
similar effect to the sight of water upon a mad dog. Again and again,
when I have spoken of the necessity of reforming our fireplaces, the
first reply elicited has been, “What, would you have us use German
stoves?” In every case where I have inquired of the exclaimer, “What
sort of a thing is a German stove?” the answer has proved that the
exclamation was but a manifestation of blind prejudice based upon
total ignorance. These people who are so much shocked at the notion
of introducing “German stoves” have no idea of the construction
of the stoves which deservedly bear this title. Their notion of a
German stove is one of those wretched iron boxes of purely English
invention known to ironmongers as “shop stoves.” These things get red
hot, their red-hot surface frizzles the dust particles that float in
the atmosphere and perfume the apartment accordingly. This, however
disagreeable, is not very mischievous, perhaps the reverse, as many of
these dust particles, which are revealed by a sunbeam, are composed
of organic matter which, as Dr. Tyndall argues, may be carriers of
infection. If we must inhale such things, it is better that we should
breathe them cooked than take them raw.
The true cause of the headaches and other mischief which such stoves
unquestionably induce is very little understood in this country. It
has been falsely attributed to over-drying of the atmosphere, and
accordingly evaporating pans and other contrivances have been attached
to such stoves, but with little or no advantage. Other explanations
are given, but the true one is that iron _when red hot is permeable by
carbonic oxide_. This was proved by the researches of Professor Graham,
who showed that this gas not only _can_ pass through red-hot iron with
singular facility, but actually _does_ so whenever there is atmospheric
air on one side and carbonic oxide on the other.
For the benefit of my non-chemical readers, I may explain that
when any of our ordinary fuel is burned, there are two products of
carbon combustion, one the result of complete combustion, the other
of semi-combustion—carbonic acid and carbonic oxide—the former,
though suffocating when breathed alone or in large proportion, is
not otherwise poisonous, and has no disagreeable odor; it is in fact
rather agreeable in small quantities, being the material of champagne
bubbles and of those of other effervescing drinks. Carbonic oxide, the
product of semi-combustion, is quite different. Breathed only in small
quantities, it acts as a direct poison, producing peculiarly oppressive
headaches. Besides this, it has a disagreeable odor. It thus resembles
many other products of imperfect combustion, such as those which are
familiar to everybody who has ever blown out a tallow candle, and left
the red wick to its own devices.
On this account alone any kind of iron stove capable of becoming
red-hot should be utterly condemned. If Englishmen did their traveling
in North Europe in the winter, their self-conceit respecting the
comfort of English houses would be cruelly lacerated, and none such
would perpetrate the absurdity of applying the name of “German stove”
to the iron fire-pots that are sold as stoves by English ironmongers.
As the Germans use so great a variety of stoves, it is scarcely correct
to apply the title of German to any kind of stove, unless we limit
ourselves to North Germany. There, and in Sweden, Denmark, Norway, and
Russia, the construction of stoves becomes a specialty. The Russian
stove is perhaps the most instructive to us, as it affords the greatest
contrast to our barbarous device of a hole in the wall into which fuel
is shoveled, and allowed to expend nine-tenths of its energies in
heating the clouds, while only the residual ten per cent does anything
towards warming the room. With the thermometer outside below zero, a
house in Moscow or St. Petersburg is kept incomparably more warm and
comfortable, and is _better_ ventilated (though, perhaps, not so
_much_ ventilated) than a corresponding class of house in England,
where the outside temperature is 20 or 30 degrees higher, and this with
a consumption of about one-fourth of the fuel which is required for the
production of British bronchitis.
This is done by, first of all, sacrificing the idiotic recreation of
fire-gazing, then by admitting no air into the chimney but that which
is used for the combustion of the fuel; thirdly, by sending as little
as possible of the heat up the chimney; fourthly, by storing the heat
obtained from the fuel in a suitable reservoir, and then allowing it
gradually and steadily to radiate into the apartment from a large but
not overheated surface.
The Russian stove by which these conditions are fulfilled is usually
an ornamental, often a highly artistic, handsome article of furniture,
made of fire-resisting porcelain, glazed and otherwise decorated
outside. Internally it is divided by thick fire-clay walls into several
upright chambers or flues, usually six. Some dry firewood is lighted
in a suitable fireplace, and is supplied with only sufficient air
to effect combustion, all of which enters below and passes fairly
through the fuel. The products of combustion being thus undiluted with
unnecessary cold air, are very highly heated, and in this state pass up
compartment or flue No. 1; they are then deflected, and pass down No.
2; then up No. 3, then down No. 4, then up No. 5, then down No. 6. At
the end of this long journey they have given up most of their heat to
the 24 heat-absorbing surfaces of the fire-clay walls of the six flues.
When the interior of the stove is thus sufficiently heated, the
fire-door and the communication with the chimney are closed, and the
fire is at once extinguished, having now done its day’s work; the
interior of the stove has bottled up its calorific force, and holds it
ready for emission into the apartment. This is effected by the natural
properties of the walls of the earthenware reservoir. They are bad
conductors and good radiators. The heat slowly passes through to the
outside of the stove, is radiated into the apartment from a large and
moderately-heated surface, which affords a genial and well-diffused
temperature throughout.
There is no scorching in one little red-hot hole, or corner, or box,
and freezing in the other parts of the room. There are no draughts, as
the chimney is quite closed as soon as the heat reservoir is supplied.
If one of these heat reservoirs is placed in the hall, where it may
form a noble ornament and can easily communicate with an underground
flue, it warms every part of the house, and enables the Russian to
enjoy a luxurious temperate climate indoors in spite of arctic winter
outside.
In a house thus warmed and free from draughts or blasts of cold air,
ventilation becomes the simplest of problems. Nothing more is required
than to provide an inlet and outlet in suitable places, and of suitable
dimensions, when the difference between the specific gravity of the
cold air without and warm air within does all the rest. Nothing is
easier to arrange than to cause all the entering air to be warmed
on its way by the hall stove, and to regulate the supply which each
apartment shall receive from this general or main stream by adjusting
its own upper outlet. In our English houses, with open chimneys, all
such systematic, scientific ventilation is impossible, on account of
the dominating, interfering, useless, and comfort-destroying currents
produced by these wasteful air-shafts.
I should add that the Russian porcelain reservoirs may be constructed
for a heat supply of a few hours or for a whole day, and I need say
nothing further in refutation of the common British prejudice which
confounds so admirable and truly scientific a contrivance with the iron
fire-pot above referred to.
There is another kind of stove, which, for the sake of distinction,
I may call Scandinavian, as it is commonly used in Norway, Sweden,
and Denmark, besides some parts of North Germany. This is a tall,
hollow iron pillar, of rectangular section, varying from three to
six feet in width, and rising half-way to the ceiling of the room,
and sometimes higher. A fire is lighted at the lower part, and the
products of combustion, in their way upwards, meet with horizontal
iron plates, which deflect them first to the right, then to the left,
and thus compel them to make a long serpentine journey before they
reach the chimney. By this means they give off their heat to the
large surface of iron plate, and enter the chimney at a comparatively
low temperature. The heat is radiated into the apartment from the
large metal surface, no part of which approaches a red-heat. A further
economy is commonly effected by placing this iron pillar in the wall
separating two rooms, so that one of its faces is in each room. Thus
two rooms are heated by one fire. One of these may be the kitchen,
and the same fire that prepares the food may be used to warm the
dining-room. The fire-worshiper is of course deprived of his “cheerful”
occupation of staring at the coals, and he also loses his playthings,
as neither poker, tongs, nor coal-scuttle are included in the furniture
of an apartment thus heated. People differently constituted consider
that an escape from the dust, dirt, and clatter of these is a decided
advantage.
Of course these stoves of our northern neighbors are costly—may be
very costly when highly ornamental. The stove of a Norwegian “bonder,”
or peasant proprietor, costs nearly half as much as the two-roomed
wooden house in which it is erected, but the saving it effects renders
it a good investment. It would cost 100_l._ or 200_l._ to fit up an
English mansion with suitable porcelain stoves of the Russian pattern,
but a saving of 20_l._ a year in fuel would yield a good return as
regards mere cost, while the gain in comfort and healthfulness would
be so great that, once enjoyed and understood, such outlay would be
willingly made by all who could afford it, even if no money saving were
effected.
Only last week I was discussing this question in a railway carriage,
where one of my fellow-passengers was an intelligent Holsteiner. He
confirmed the heresy by which I had shocked the others, in exulting in
the high price of coal, and wishing it to continue. He told us that
when wood was abundant in his country, fuel was used as barbarously,
as wastefully, and as inefficiently as it now is here, but that the
deforesting of the land, and the great cost of fuel, forced upon them a
radical reform, the result of which is that they now have their houses
better warmed, and at a less cost than when fuel was obtainable at one
fourth of its present cost.
Such will be the case with us also if we can but maintain the present
coal famine during one or two more winters, especially if we should
have the further advantage of some very severe weather in the meantime.
Hence the cruel wishes above expressed. The coal famine would scarcely
be necessary if we had Russian winters, for in such case our houses,
instead of being as they are, merely the most uncomfortable in North
Europe, would be quite uninhabitable. With our mild winters we require
the utmost severity of fuel prices to civilize our warming and
ventilating devices.
“BAILY’S BEADS.”
TO THE EDITOR OF THE _Times_.
SIR,—The curious breaking up of the thin annular rim of the sun which
is uncovered just before and just after totality, or which surrounds
the moon during an annular eclipse, has been but occasionally observed,
and some scepticism as to the accuracy of Baily’s observations has
lately arisen. Having attempted an explanation of the “beads,” I have
looked with much interest for the reports of the eclipse of 1870, for,
if I am right, they ought to have been well seen on this occasion. This
has been the case. We are informed that both Lord Lindsay and the Rev.
S. J. Perry have observed them, and that Lord Lindsay has set aside all
doubts respecting their reality by securing a photographic record of
their appearance.
My explanation is that they are simply sun-spots seen in profile—spots
just caught in the fact of turning the sun’s edge. All observers are
now agreed as to the soundness of Galileo’s original description of
the spots—that they are huge cavities, great rifts of the luminous
surface of the sun, many thousands of miles in diameter, and probably
some thousand miles deep. Let us suppose the case of a spot—say, 2,000
miles deep and 10,000 miles across (Sir W. Herschel has measured spots
of 50,000 miles diameter). When such a spot in the course of the sun’s
rotation reaches that part which forms the visible edge of the sun, it
must, if rendered visible, be seen as a notch; but what will be the
depth of such a notch? Only about 1-430th of the sun’s diameter. But
the apparent depth would be much less as the edge or rim of the spot
next to the observer would cut off more or less of its actually visible
depth, this amount depending upon the lateral or east and west diameter
of the spot and its position at the time of observation.
Thus, the visible depth of such a notch would rarely exceed one
thousandth of the sun’s apparent diameter, or might be much less. The
sun being globular, the edge which is visible to us is but our horizon
of his fiery ocean, which we see athwart the intervening surface as
it gradually bends away from our view. So small an indent upon this
edge would, under ordinary circumstances of observation, be rendered
quite invisible by the irradiation of the vast globular surface of the
glaring photosphere, upon which it would visually encroach.
If, however, this body of glare could be screened off, and only a line
of the sun’s edge, less than one thousandth of his diameter, remain
visible, the notch would appear as a distinct break in this curved line
of light. If a group of spots, or a great irregular spot with several
umbræ, were at such a time situated upon the sun’s edge, the appearance
of a series of such notches or breaks leaving intermediate detachments
of the visible ring of the photosphere would be the necessary result,
and thus would be presented exactly the appearance described as
“Baily’s beads.”
I have been led to anticipate a display of these beads during the
late eclipse by the fact that some days preceding it a fine group of
spots—visible to the naked eye through a London fog—were traveling
towards the eastern edge of the sun, and should have reached the limb
at about the time of the eclipse. The beads were observed by the Rev.
S. J. Perry just where I expected them to appear. I have not yet learnt
on which side of the sun they were observed and photographed by Lord
Lindsay.
Baily’s first observation of the beads was made during the annular
eclipse of May 15, 1836. That year, like 1870, was remarkable for a
great display of sun-spots. As in 1870, they were then visible to the
naked eye. I well remember my own boyish excitement when, a few weeks
before the eclipse of 1836, I discovered a spot upon the reddened face
of the setting sun—a thing I had read about, and supposed that only
great astronomers were privileged to see. The richness of this sun-spot
period is strongly impressed on my memory by the fact that I continued
painfully watching the dazzling sun, literally “watching and weeping,”
up to the Sunday of the eclipse, on which day also I saw a large spot
through my bit of smoked glass.
The previous records of these appearances of fracture of the thin line
of light are those of Halley, in his memoir on the total eclipse of
1715, and Maclauren’s on that of 1737. Both of these correspond to
great spot periods; the intervals between 1715, 1737, 1836, and 1870
are all divisible by eleven. The observed period of sun-spot occurrence
is eleven years and a small fraction.
I am anxiously awaiting the arrival of Lord Lindsay’s long-exposure
photographs of the corona, for if they represent the varying degrees of
splendor of this solar appendage, the explanations offered in Chapter
xii. of my essay on “The Fuel of the Sun” will be very severely tested
by them.
Yours respectfully,
W. MATTIEU WILLIAMS.
Woodside Green, Croydon, January 4, 1871.
THE COLORING OF GREEN TEA.
The following is a copy of my report to the _Grocer_ on a sample of the
ingredients actually used by the Chinese for coloring of tea, which
sample was sent to the _Grocer_ office by a reliable correspondent
at Shanghai (November, 1873). I reprint it because the subject has a
general interest and is commonly misunderstood:
I have examined the blue and the yellowish-white powders received from
the office, and find that the blue is not indigo, as your Shanghai
correspondent very naturally supposes, but is an ordinary commercial
sample of Prussian blue. It is not so bright as some of our English
samples, and by mere casual observation may easily be mistaken for
indigo. Prussian blue is a well-known compound of iron, cyanogen,
and potassium. Commercial samples usually contain a little clayey or
other earthy impurities, which is the case with this Chinese sample.
There are two kinds of Prussian blue—the insoluble, and the basic or
soluble. The Chinese sample is insoluble.
This is important, seeing that we do not eat our tea-leaves, but merely
drink an infusion of them; and thus even the very small quantity which
faces the tea-leaf remains with the spent leaves, and is not swallowed
by the tea-drinker, who therefore need have no fear of being poisoned
by this ornamental adulterant.
Its insolubility is obvious, from the fact that green tea does not give
a blue infusion, which would be the case if the Prussian blue were
dissolved.
There are some curious facts bearing on this subject and connected with
the history of the manufacture of Prussian blue. Messrs. Bramwell, of
Newcastle-on-Tyne, who may be called the fathers of this branch of
industry, established their works about a century ago. It was first
sold at two guineas per lb.; in 1815 it had fallen to 10_s._ 6_d._, in
1820 to 2_s._ 6_d._, then down to 1_s._ 9_d._ in 1850. I see by the
Price Current of the _Oil Trade Review_ that the price has recently
been somewhat higher.
In the early days of the trade a large portion of Messrs. Bramwell’s
produce was exported to China. The Chinese then appear to have been the
best customers of the British manufacturers of this article. Presently,
however, the Chinese demand entirely ceased, and it was discovered that
a common Chinese sailor, who had learned something of the importation
of this pigment to his native country, came to England in an East
Indiaman, visited, or more probably obtained employment at a Prussian
blue manufactory, learned the process, and, on his return to China,
started there a manufactury of his own, which was so successful that
in a short time the whole of the Chinese demand was supplied by native
manufacture; and thus ended our export trade. Those who think the
Chinese are an unteachable and unimprovable people may reflect on this
little history.
The yellowish powder is precisely what your Shanghai correspondent
supposes. It is steatite, or “soapstone.” This name is very deceptive,
and coupled with the greasy or unctuous feel of the substance,
naturally leads to the supposition that it is really as it appears, an
oleaginous substance. This, however, is not the case. It is a compound
of silicia, magnesia, and water, with which are sometimes associated
a little clay and oxide of iron. Like most magnesian minerals, it has
a curiously smooth or slippery surface, and hence its name. It nearly
resembles meerschaum, the smoothness of which all smokers understand.
When soapstone is powdered and rubbed over a moderately rough surface,
it adheres, and forms a shining film; just as another unctuous mineral,
graphite (the “black-lead” of the housemaid), covers and polishes
ironwork. On this account, soapstone is used in some lubricating
compounds, for giving the finishing polish to enameled cards, and for
other similar purposes.
With a statement of these properties before us, and the interesting
description of the process by your Shanghai correspondent, the whole
riddle of green-tea coloring and facing is solved. The Prussian blue
and soapstone being mixed together when dry in the manner described,
the soapstone adheres to the surface of the particles of blue, and
imparts to them not only a pale greenish color, but also its own
unctuous, adhesive, and polishing properties. The mixture being well
stirred in with the tea-leaves, covers them with this facing, and thus
gives both the color and peculiar pearly lustre characteristic of some
kinds of green tea. I should add that the soapstone, like the other
ingredient, is insoluble, and therefore perfectly harmless.
Considering the object to be attained, it is evident from the above
that John Chinaman understands his business, and needs no lessons from
European chemists. It would puzzle all the Fellows of the Chemical
Society, though they combined their efforts for the purpose, to devise
a more effective, cheap, simple, and harmless method of satisfying the
foolish demand for unnaturally colored tea-leaves.
When the tea-drinking public are sufficiently intelligent to prefer
naturally colored leaves to the ornamental stuff they now select, Mr.
Chinaman will assuredly be glad enough to discontinue the addition
of the Prussian blue, which costs him so much more per pound than
his tea-leaves, and will save him the trouble of the painting and
varnishing now in demand.
In the meantime, it is satisfactory to know that, although a few silly
people may be deceived, nobody is poisoned by this practice of coloring
green tea. I say “a few silly people,” for there can be only a few,
and those very silly indeed, who judge of their tea by its appearance
rather than by the quality of the infusion it produces.
With these facts before us it is not difficult to trace the origin of
the oft-repeated and contradicted statement that copper is used in
coloring green tea. One of the essential ingredients in the manufacture
of Prussian blue is sulphate of iron, the common commercial name which
is “green copperas.” It is often supposed to contain copper, but this
is not the case.
Your Shanghai correspondent overrates the market value of soapstone
when he supposes that Chinese wax may be used as a cheap substitute. In
many places—as, for instance, the “Lizard” district of Cornwall—great
veins of this mineral occur, which, if needed, might be quarried in
vast abundance, and at very little cost on account of its softness. The
romantic scenery of Kynance Cove, its caverns, its natural arches, the
“Devil’s Bellows,” the “Devil’s Post-office,” the “Devil’s Cauldrons,”
and other fantastic formations of this part of the coast, attributed to
his Satanic Majesty or the Druids, are the natural results of the waves
beating away the veins of soft soapstone, and leaving the deformed
skeleton rocks of harder serpentine behind.
“IRON FILINGS” IN TEA.
I have watched the progress of the tea controversy and the other public
performances of the public analysts with considerable interest; it
might have been with amusement, but for the melancholy degradation of
chemical science which they involve.
Among the absurdities and exaggerations which for some years past
have been so industriously trumpeted forth by the pseudo-chemists who
trade upon the adulteration panic and consequent demand for chemical
certificates of purity, the continually repeated statements concerning
the use of iron filings as a fraudulent adulterant of tea take a
prominent place. I need scarcely remark that, in order to form such an
adulterant, the quantity added must be sufficiently great to render its
addition commercially profitable to an extent commensurate with the
trouble involved.
The gentlemen who, since the passing of the Adulteration Act, have by
some kind of inspiration suddenly become full-blown chemists, have
certified to wilful adulteration of tea with iron filings, and have
obtained _convictions_ on such certificates, when, according to their
own statement, the quantity contained has not exceeded 5 per cent
in the cheapest qualities of tea. Now, the price of such tea to the
Chinaman tea-grower, who is supposed to add these iron filings, is
about fourpence to sixpence per pound; and we are asked to believe that
he will fraudulently deteriorate the market value of his commodity for
the sake of this additional 1-20th of weight. Supposing that he could
obtain his iron filings at twopence per pound, his total gain would
thus be about 1-10th of a penny per pound. But can he obtain such iron
filings in the quantity required at such a price? A little reflection
on a few figures will render it evident that he cannot, and that such
adulteration is utterly impossible.
I find by reference to _The Grocer_ of November 8th, that the total
deliveries of tea into the port of London during the first ten months
of 1872 were 142,429,337 lbs., and during the corresponding period of
1873, 139,092,409 lbs. Of this about 8½ millions of pounds in 1873,
and 10 millions of pounds in 1872, were green, the rest black. This
gives in round numbers about 160 millions of pounds of black tea per
annum, of which above 140 millions come from China. As the Russians
are greater tea-drinkers than ourselves—the Americans and British
colonists are at least equally addicted to the beverage, and other
nations consume some quantity—the total exports from China may be
safely estimated to reach 400 or 500 millions of pounds.
Let us take the smaller figure, and suppose that only one fourth of
this is adulterated, to the extent of 5 per cent, with iron filings.
How much would be required? Just five millions of pounds per annum.
It must be remembered that _coarse_ filings could not possibly be used;
they would show themselves at once to the naked eye as rusty lamps, and
would shake down to the bottom of the chest; neither could borings,
nor turnings, nor plane-shavings be used. Nothing but _fine_ filings
would answer the supposed purpose. I venture to assert that if the
China tea-growers were to put the whole world under contribution for
their supposed supply of fine iron filings, this quantity could not be
obtained.
Let anyone who doubts this borrow a blacksmith’s vice, a fine file, and
a piece of soft iron, then take off his coat and try how much labor
will be required to produce a single ounce of filings, and also bear
in mind that fine files are but very little used in the manufacture of
iron. As the price of a commodity rises when the demand exceeds the
supply the Chinaman would have to pay far more for his adulterant than
for the leaves to be adulterated. As Chinese tea-growers are not public
analysts, we have no right to suppose that they would perpetrate any
such foolishness.
The investigations recently made by Mr. Alfred Bird, of Birmingham,
show that the iron found in tea-leaves is not in the metallic state,
but in the condition of oxide; and he confirms the conclusions of
Zöller, quoted by Mr. J. A. Wanklyn in the _Chemical News_ of October
10th—viz., that compounds of iron naturally exist in genuine tea.
It appears, however, that the ash of many samples of _black_ tea
contains more iron than naturally belongs to the plant; and, accepting
Mr. Bird’s statement, that this exists in the leaf as oxide mixed
with small siliceous and micaceous particles I think we may find a
reasonable explanation of its presence without adopting the puerile
theory of the adulteration maniac, who, in his endeavor to prove that
everybody who buys or sells anything is a swindler, has at once assumed
the impossible addition of iron filings as a makeweight.
In the first place we must remember that the commodity in demand is
_black_ tea, and that ordinary leaves dried in an ordinary manner are
not black, but brown. Tea-leaves, however, contain a large quantity
of tannin, a portion of which is, when heated in the leaves, rapidly
convertible into gallo-tannic or tannic acid. Thus a sample of tea
rich in iron would, when heated in the drying process, become, by the
combination of this tannic acid with the iron it contains, much darker
than ordinary leaves or than other teas grown upon less ferruginous
soils and containing less iron.
This being the case, and a commercial demand for _black_ tea having
become established, the tea-grower would naturally seek to improve the
color of his tea, especially of those samples naturally poor in iron,
and a ready mode of doing this is offered by stirring in among the
leaves while drying a small additional dose of oxide of iron, if he can
find an oxide in such a form that it will spread over the surface of
the leaf as a thin film. Now, it happens that the Chinaman has lying
under his feet an abundance of material admirably adapted for this
purpose—viz., red hæmatite, some varieties of which are as soft and
unctuous as graphite, and will spread over his tea-leaves exactly in
the manner required. The micaceous and siliceous particles found by Mr.
Bird are just what should be found in addition to oxide of iron, if
such hæmatite were used.
The film of oxide thus easily applied, and subjected to the action of
the exuding and decomposing extractive matter of the heated leaves,
would form the desired black dye or “facing.”
The knotty question of whether this is or is not an adulteration is
one that I leave to lawyers to decide, or for those debating societies
that discuss such interesting questions as whether an umbrella is an
article of dress. If it is an adulteration, and, as already admitted,
is not at all injurious to health, then all other operations of dyeing
are also adulterations; for the other dyers, like the Chinaman, add
certain impurities to their goods—the silk, wool, or cotton—in order
to alter their natural appearance, and to give them the false facing
which their customers demand, but with this difference, if I am right
in the above explanation: that in darkening tea nothing more is done
but to increase the proportion of one of its natural ingredients, and
to intensify its natural color; while in the dyeing of silk, cotton, or
wool, ingredients are added which are quite foreign and unnatural, and
the natural color of the substance is altogether falsified.
The above appeared in the _Chemical News_ November 21, 1873, when
the adulteration in question was generally believed to be commonly
perpetrated, and many unfortunate shop-keepers had been and were
still being summoned to appear at Petty Sessions, etc., and publicly
branded as fraudulent adulterators on the evidence of the newly-fledged
public analysts, who confidently asserted that they found such filings
mixed with the tea. Some discussion followed in subsequent numbers of
the _Chemical News_; but it only brought out the fact that “finely
divided iron” exists in considerable quantities in Sheffield,—may be
“begged,” as Mr. Alfred H. Allen (an able analytical chemist, resident
in Sheffield,) said. The fact that such finely divided iron is thus
without commercial value still further confirms my conclusion that it
is not used for the adulteration of tea. If it were, its collection
would be a regular business, and truck-loads would be transmitted from
Sheffield to London, the great centre of tea-importation. No evidence
of any commercial transactions in iron filings or iron dust for such
purposes came forward in reply to my challenge.
The practical result of the controversy is that iron filings are no
longer to be found in the analytical reports of the adulteration of
tea.
CONCERT-ROOM ACOUSTICS.
The acoustics of public buildings are now occupying considerable
attention in London. The vast audiences which any kind of sensational
performance in the huge metropolis is capable of attracting, is forcing
the subject upon all who cater for public amusement or instruction.
There was probably no building in London, or anywhere else, more
utterly unfit for musical performances than the Crystal Palace in its
original condition; but, nevertheless, the Handel Festival of last week
was a great success. I attended the first of these immense gatherings,
and this last; but nothing of the kind intermediate, and, therefore, am
the better able to make comparisons.
My recollections of the first were so very unsatisfactory that I
gladly evaded the grand rehearsal of Friday week, and went to the
“Messiah” on Monday with an astronomical treatise in my pocket, in
order that my time should not be altogether wasted. Being seated at
the further end of the transept, in a gallery above the level of the
general ridge-and-furrow roof of the nave, the plump little Birmingham
tenor, who rose to sing the first solo, appeared, under the combined
optical conditions of distance and vertical foreshortening, like a
chubby cheese-mite viewed through a binocular microscope. Taking it
for granted that his message of comfort could not possibly reach my
ear, I determined to anticipate the exhortation by settling down for a
comfortable reading of a chapter or two, but was surprised to find I
could hear every note, both of recitative and air.
It thus became obvious that the alterations that have gradually grown
since the time when Clara Novello’s voice was the only one that could
be heard across the transept are worthy of study; that the advertised
success of the “velarium” is something more than mere puffery. I
accordingly used my eyes as well as my ears, and made a few notes
which may be interesting to musical and architectural, as well as to
scientific readers.
Sound, like light, heat, and all other radiations, loses its intensity
as it is outwardly dispersed, is enfeebled in the ratio of the squares
of distance; thus at twenty feet from the singer the loudness of the
sound is one fourth of that at ten feet, at thirty feet one ninth, at
forty feet one sixteenth, at fifty feet one twenty-fifth, and so on;
that is, supposing the singer or other source of sound is surrounded on
all sides by free, open, and still air.
But this condition is never fulfilled in practice, excepting, perhaps,
by Simeon Stylites when he preached to the multitude from the top of
his column. If Mr. Vernon Rigby had stood on the top of one of his
native South Staffordshire chimney-shafts, of the same height above the
ground as the upper press gallery of the Crystal Palace is above the
front of the orchestra, and I had stood on the open ground at the same
distance away and below him, his solo of “Comfort ye, my People” would
have been utterly inaudible.
What, then, is the reason of this great difference of effect at equal
distances? If we can answer this question, we shall know something
about the acoustics of concert-rooms.
The uninitiated reader will at once begin by saying that “sound
rises.” This is almost universally believed, and yet it is a great
mistake, as commonly understood. Sound radiates equally in every
direction—downwards, upwards, north, south, east, or west, unless some
special directive agency is used. The directive agency commonly used is
a reflecting or reverberating surface.
Thus the voice of the singer travels forward more abundantly than
backward, because he uses the roof, and, to some extent, the walls and
floor of his mouth, as a sound reflector. The roof of his mouth being
made of concave plates of bone with a thin velarium of integument
stretched tightly over them, supplies a model sound reflector; and
I strongly recommend every architect who has to build a concert or
lecture-room, or theatre, to study the roof of his own mouth, and
imitate it as nearly as he can in the roof of his building.
The great Italian singing masters of the old school, who, like the
father of Persiani, could manufacture a great voice out of average raw
material, studied the physiology of the vocal organs, and one of their
first instructions to their pupils was that they should sing against
the roof of the mouth, then throw the head back and open the mouth,
so that the sound should reverberate forwards, clear of the teeth and
lips. For the first year or two the pupil had to sing only “la, la,”
for several hours per day, until the faculty of doing this effectually
and habitually was acquired.
The popular notion that sound rises has probably originated from the
fact that in our common experience the sounds are produced near to some
kind of floor, which reflects the sounds upwards, and thus adds the
reflected sound to that which is directly transmitted, and thereby the
general result is materially augmented.
But if we would economize sound most effectively, we must have not only
a reflecting floor, but also a reflecting roof and reflecting walls
on all sides of the concert room. These are the conditions that were
wanting in the original structure of the Crystal Palace transept, for
then the sound of the singer’s voice could travel upwards to that lofty
arch and sidewise in all directions, almost as freely as in the open
air.
This defect has been remedied to a very great extent by the velarium
stretched across from the springing of the great arch of glass and
iron, and forming a ceiling to the concert-room part of the building.
Besides this, a wall of drapery is stretched across each side of the
transept, and the orchestra has its special walls, roof, and back.
There are other minor arrangements for effecting lateral reverberation;
that is, for returning the sound into the auditorium proper instead of
allowing it to wander feebly throughout the building.
The general result of these arrangements is to render that portion of
the building in which the reserved seats are placed a really luxurious
and efficient concert-room, of magnificent proportions; but, very
unfortunately and inevitably, these conditions, which are so favorable
for the happy eight or nine thousand who can afford reserved seats,
render the position of the other half-dozen thousand outsiders more
disappointing and vexatious than ever. For my own part I would rather
spend a holiday afternoon in the mild atmosphere and the quiet,
soothing gloom of a coal-pit than be teased and irritated by a strained
listening to the indefinite roar of a grand choir, and the occasional
dying vibrations of Sims Reeves’ “top A.”
I have in the above advocated reverberation as a remedy for diffusion
of sound. This may, perhaps, appear rather startling to some musicians
who have a well-founded dread of echoes, and who read the words _echo_
and _reverberation_ as synonymous. This requires a little explanation.
As light is transmitted, reflected, and absorbed in the same manner as
sound, and as light is visible—or, rather, renders objects visible—I
will illustrate my meaning by means of light.
Let us suppose three apartments of equal size and same shape, one
having its walls covered with mirrors, the second with white paper,
and the third with black woollen cloth, and all lighted with central
chandeliers of equal brilliancy. The first and second will be much
lighter than the third, but they will be illuminated very differently.
In the first, there will be a repetition of chandeliers in the mirrored
walls, each wall definitely reflecting the image of each particular
light. In the second room there will be reflection also, and economy of
light, but no reflection of definite images; the apartment will appear
to be filled with a general and well-diffused luminosity, rendering
every object distinctly visible, and there will be no deep shadows
anywhere.
In scientific language, we shall have, in the first room, _regular
reflection_; in the second, _scattering reflection_; in the third room
we should have comparative gloom, owing to the _absorption_ of the
light by the black cloth.
We may easily suppose the parallels of these in the case of sound. If
the velarium and side walls of the transept and orchestra were made
of sheet iron, or smooth, bare, unbroken vibrating wooden boards, we
should have a certain amount of _regular_ reflection of sound or echo.
Just as we should see the particular lights of the chandelier reflected
in the first room, so should we hear the particular notes of the
singer or player echoed by such regularly vibrating walls and ceiling.
If, again, the velarium and side drapery of the transept and orchestra
had been thick, soft woollen cloths, the sound, like the light, would
have been absorbed or “muffled,” and, though very clear, it would be
weak and insufficient.
The reader will now ask—What, then, is the right material for such
velarium and walls? I cannot pretend to say what is the best possible,
believing that it has yet to be discovered. The best yet known, and
attainable at moderate expense, is common canvas or calico, washed
or painted over with a mixture of size and lime, or other attainable
material that will fill up the pores of the fabric, and give it
a moderately smooth face or surface. Thus prepared, it is found
to reflect sound, as paper, ground glass, etc., reflect light, by
scattering reverberation, but without definite echo.
It will now be understood how the velarium acted in rendering the solos
so clearly audible at the great height and distance of the Upper Press
Gallery. Instead of being wasted by diffusion in the great vault above,
they were stopped and reflected by the velarium, but not so reflected
as to produce disagreeable repetition notes, just audible at particular
points, as the lights of the mirror reflections of the chandeliers
would be.
Flat surfaces reflect radially, while concave surfaces with certain
curves reflect sound, light, heat, etc., in parallel lines. The walls
and roof of a music-hall should scatter their reflections on all sides,
and, therefore, should be flat, or nearly so, excepting at the angles,
which should be curved or hollowed. From the orchestra the sound is
chiefly required to be projected forward as from the singer’s mouth;
and, therefore, an orchestra should have curved walls and roof.
Space will not permit a dissertation here on the particular curve
required. This has, I believe, been carefully calculated in
constructing the Crystal Palace orchestra. Viewed from a distance,
the whole orchestra is curiously like a huge wide-opened mouth that
only requires to close a little and open a little more, according to
the articulations of the choir, to represent the vocal effort of one
gigantic throat.
There is, I think, one fault in the shape of this mouth. It extends too
far laterally in proportion to its perpendicular dimensions. The angles
of the mouth are too acute; the choir extends too far on each side. The
singers should be packed more like those of the Birmingham Festival
Choir.
There is an acoustic limit to the magnitude of choirs. Sound travels
at about 1100 feet per second, and thus, if one of the singers of a
choir is 110 feet nearer than another singer to any particular auditor,
the near singer will be heard one-tenth of a second before the more
distant, though they actually sing exactly together. In rapid staccato
passages this would produce serious confusion, though in such music as
most of Handel’s it would be scarcely observable.
Some observations which I have made convince me that the actual choir
of the Handel Festivals has reached, if not exceeded, the acoustic
limits even for Handel’s music, and decidedly exceeds the limits
permissible for Mendelsshon and most other composers.
I found that when standing on the floor of the building in front of the
orchestra, and on one side, I could plainly distinguish the wave of
difference of time due to the traveling of the sound, and in all the
passages which required to be taken up smartly and simultaneously by
the opposite sides of the choir, the effect was very disagreeable.
The defect, however, was not observable from the press gallery, which
is placed as nearly as may be to the focus of the orchestral curve,
so that radial lines drawn from the auditor to different parts of the
orchestra do not differ so much in length as to effect perceptible
differences in the moment at which the different sounds reach the ear.
My conclusion, therefore, is that if any amendment is to be made in the
numbers of the Handel Festival choir, it should rather be done by a
reduction than an increase; that the four thousand voices should rather
be reduced to three thousand than increased to five thousand. With
greater severity of selection as regards quality, power, and training
of each individual voice, and with better packing, the three thousand
would be more effective than the four thousand.
SCIENCE AND SPIRITUALISM.
A rather startling paper in the current number of the “Quarterly
Journal of Science,” from the pen of William Crookes, F.R.S. (who
is well known in the scientific world by his discovery of the metal
thallium, his investigations of its properties and those of its
compounds, besides many other important researches, and also as the
able and spirited editor of the _Chemical News_), is now the subject of
much scientific gossip and discussion.
Mr. Crookes has for some time past been engaged in investigating some
of the phenomena which are attributed on one hand to the agency of
spiritual visitors, and on the other side to vulgar conjuring. Nobody
acquainted with Mr. Crookes can doubt his ability to conduct such an
investigation, or will hesitate for a moment in concluding that he has
done so with philosophical impartiality, though many think it quite
possible that he may have been deceived. None, however, can yet say how.
For my own part, I abstain from any conclusion in the meantime, until
I have time and opportunity to witness a repetition of some of these
experiments, and submitting them to certain tests which appear to me
desirable. Though struggling against a predisposition to prejudge, and
to conclude that the phenomena are the results of some very skillful
conjuring, I very profoundly respect the moral courage that Mr. Crookes
has displayed in thus publicly grappling with a subject which has
been soiled by contact with so many dirty fingers. Nothing but a pure
love of truth, overpowering every selfish consideration, could have
induced Mr. Crookes to imperil his hard-earned scientific reputation by
stepping thus boldly on such very perilous ground.
It is only fair, at the outset, to state that Mr. Crookes is not
what is called “a spiritualist.” This I infer, both from what he has
published and from conversation I have had with him on the subject.
He has witnessed some of the “physical manifestations,” and, while
admitting that many of these may be produced by the jugglery of
impostors, he has concluded that others cannot be thus explained; but,
nevertheless, does not accept the spiritual theory which attributes
them to the efforts of departed human souls.
He suspects that the living human being may have the power of exerting
some degree of force or influence upon bodies external to himself—may,
for instance, be able to counteract or increase the gravitation of
substances by an effort of the will. He calls this power the “psychic
force,” and supposes that some persons are able to manifest it much
more powerfully than others, and thus explains the performances of
those “mediums” who are not mere impostors.
There is nothing in this hypothesis which the sternest, the most
sceptical, and least imaginative of physical philosophers may not
unhesitatingly investigate, provided some first-sight evidence of
its possibility is presented to him. We know that the Torpedo, the
Gymnotus, the Silurus Electricus, and other fishes, can, by an effort
of the will, act upon bodies external to themselves. Faraday showed
that the electric eel exhibited some years ago at the Adelaide Gallery
was able, by an effort of its will, to make a magnetic needle suddenly
turn thirty degrees aside from its usual polar position; that this same
animal could—still by an effort of will—overpower the gravitation
of pieces of gold leaf, cause them to be uplifted and outstretched
from their pendent position, could decompose iodide of potassium, and
perform many other “physical manifestations,” simply by a voluntary
nervous effort, and without calling in the aid of any souls of other
departed eels.
Before this gymnotus was publicly exhibited it was deposited at
a French hotel in the neighborhood of Leicester Square. A burly
fishmonger’s man, named Wren, brought in the daily supply of fish to
the establishment, when some of the servants told him they had an eel
so large that he would be afraid to pick it up. He laughed at the idea
of being afraid of an eel, and when taken to the tub boldly plunged
in both hands to seize the fish. A hideous roar followed this attempt.
Wren had experienced a demonstration of the “psychic force” of the
electrical eel, and his terror so largely exaggerated the actual
violence of the shock, that he believed for the remainder of his life
that he was permanently injured by it. He had periodical spasms across
the chest, which could only be removed by taking a half-quartern of
gin. As he was continually narrating his adventure to public-house
audiences, and always had a spasm on concluding, which his hearers
usually contributed to relieve, the poor fellow’s life was actually
shortened by the shock from the gymnotus.
The experiments which Mr. Crookes relates in support of his psychic
force hypothesis are as follows:—In the first place he contrived
an apparatus for testing Mr. Home’s alleged power of modifying the
gravitation of bodies. As Mr. Home requires to lay his hands, or at
least his finger-ends, upon the body to be influenced, Mr. Crookes
attached one end of a long board to a suspended spring steelyard of
delicate construction; the other end of the board rested on a fulcrum
in such a manner that one half of the weight of the board was supported
by the fulcrum and the other half by the steelyard. The weight of the
board thus suspended was carefully noted, and then Mr. Home put his
fingers upon that end of the board immediately resting on the fulcrum
in such a manner that he could not by simple pressure affect the
dependent end of the board.
Dr. Huggins, the eminent astronomer, was present, and also Serjeant
Cox, besides Mr. Crookes. They all watched Mr. Home, the board, and
the steelyard; they observed first a vibration and fluctuation of the
index, and finally that the steelyard indicated an increase of weight
amounting to about three pounds. Mr. Crookes tried to produce the
same effect by mechanical pressure exerted in a similar manner, but
failed to do so. The details of the experiment are fully described and
illustrated by an engraving.
Another and still more striking experiment is described. Mr. Crookes
purchased a new accordion from Messrs. Wheatstone, and himself
constructed a wire cage open at top and bottom, and large enough for
the accordion to be suspended within it by holding it over the open
top, while the bottom of the cage rested on the floor. The accordion
was then handed to Mr. Home, who held it with one hand by the wooden
framework of the bottom of the instrument, as shown in an illustrative
drawing. The keys were thus hanging downwards and the bellows distended
by the weight of the instrument thus pendent. It was then held so that
it should be entirely surrounded by the wire-work of the cage, and the
results were, as before, watched keenly by Mr. Crookes, Dr. Huggins,
and Serjeant Cox. After a while the instrument began to wave about,
then the bellows contracted, and the lower part (_i.e._, the key-board
end) rose a little, presently sounds were produced, and finally the
instrument played a tune upon itself in obedience, as Mr. Crookes
supposes, to the psychic force which Mr. Home exerted upon it.
Before the publication of the paper describing these experiments a
proof was sent to both Dr. Huggins and Serjeant Cox, and each has
written a letter testifying to its accuracy, which letters are printed
with the paper in the “Quarterly Journal of Science.”
Here, then, we have the testimony of an eminent lawyer, accustomed
to sifting evidence, that of the most distinguished of experimental
astronomers, the man whose discoveries in celestial physics have justly
excited the admiration of the whole civilized world; and besides these,
of another Fellow of the Royal Society, who has been severely trained
in “putting nature to the torture” by means of the most subtle devices
of the modern physical and chemical laboratory.
Such testimony must not be treated lightly. It would be simple
impertinence for any man dogmatically to assert that these have been
deceived merely because he is unconvinced.
Though one of the unconvinced myself, I would not dare to regard the
investigations of these gentlemen with any other than the profoundest
respect. Still a suggestion occurs to me which may appear very brutal,
but I make it nevertheless. It is this:—That the testimony of another
witness—of an expert of quite a different school—should have been
added. I mean such a man as Döbler, Houdin, or the Wizard of the North.
He might possibly have detected something which escaped the scrutiny of
the legitimate scientific experimentalist.
There is one serious defect in the accordion experiment. The cage is
represented in the engraving as placed under a table; Mr. Home holds
the instrument in his hand, which is concealed by the table, and it
does not appear that either Mr. Crookes, Dr. Huggins, or Serjeant Cox
placed themselves under the table during the concertina performance,
and thus neither of them saw Mr. Home’s hand. Such, at least, appears
from the description and the engraving. A story being commonly
circulated respecting some of Mr. Home’s experiments in Russia,
according to which he failed entirely when a glass table was provided
instead of a wooden one, it would be well, if only in justice to Mr.
Home, to get rid of the table altogether.
It is very desirable that these experiments should be continued, for
two distinct reasons; first, as a matter of ordinary investigation for
philosophical purposes, and, secondly, as a means of demolishing the
most degrading superstition of this generation.
If Mr. Crookes succeeds in demonstrating the existence of the psychic
force and reducing it to law—as it must be reducible if it is a
force—then the ground will be cut from under the feet of spiritualism,
just as the old superstitions, which attributed thunder and lightning
to Divine anger, were finally demolished by Franklin’s kite. If, on
the other hand, the arch-medium, Mr. Home, is proved to be a common
conjuror, then surely the dupes of the smaller “mediumistic” fry
will have their eyes opened, provided the cerebral disturbance which
spiritualism so often induces has not gone so far as to render them
incurable lunatics.
It is very likely that I shall be accused of gross uncharitableness
in thus applying the term lunatic to “those who differ from me,” and
therefore state that I have sad and sufficient reasons for doing so.
The first spiritualist I ever knew, and with whom I had many
conferences on the subject many years ago, was a lady of most estimable
qualities, great intellectual attainments, and distinguished literary
reputation. I watched the beginning and the gradual progress of her
spiritual “investigations,” as she called them, and witnessed the
melancholy end—shocking delusions, intellectual shipwreck, and
confirmed, incurable insanity, directly and unmistakably produced by
the action of these hideous superstitions upon an active, excitable
imagination.
I well remember the growing symptoms of this case, have seen their
characteristic features repeated in others, and have now before me some
melancholy cases where the same changes, the same decline of intellect
and growth of ravenous credulity, is progressing with most painfully
visible distinctness.
The necessity for some strong remedy is the more urgent, inasmuch as
the diabolical machinery of the spiritual impostors has been so much
improved of late. The lady whose case I first referred to had reached
the highest stage of spiritualistic development—viz., the lunatic
asylum—before “dark séances” had been invented, or, at any rate,
before they were introduced into this country. When the conditions of
these séances are considered, it is not at all surprising that persons
of excitable temperament, especially women, should be morbidly affected
by them.
We are endowed with certain faculties, and placed in a world wherein
we may exercise them healthfully upon their legitimate objects. Such
exercise, properly limited, promotes the growth and vigor of our
faculties; but if we pervert them by directing them to illegitimate
objects, we gradually become mad. God has created the light, and fitted
our eyes to receive it; He has endowed us with the sense of touch, by
which we may confirm and verify the impressions of sight. All physical
phenomena are objects of sense, and the senses of sight and touch are
the masters of all the other senses.
Can anything, then, be more atrociously perverse, more utterly idiotic,
and I may even say impious, than these dark séance investigations? Is
it possible to conceive a more melancholy spectacle of intellectual
degradation than that presented by a group of human victims assembled
for the purpose of “investigating physical manifestations,” and
submitting, as a primary condition, to be blinded and handcuffed, the
room in which they sit being made quite dark, and both hands of each
investigator being firmly held by those of his neighbors. That is to
say, the primary conditions of making these physical investigations is
that each investigator shall be deprived of his natural faculties for
doing so.
When we couple this with the fact that these meetings are got
up—publicly advertised by adventurers who make their livelihood by the
fees paid by their hoodwinked and handcuffed customers—is it at all
surprising that those who submit to such conditions should finish their
researches in a lunatic asylum?
The gloom, the mystery, the unearthly objects of search, the mysterious
noises, and other phenomena so easily manipulated in the presence of
those who can see nothing and feel only the sympathetic twitching of
another pair of trembling hands, naturally excites very powerfully the
poor creatures who pay their half-crowns and half-guineas with any
degree of faith; and this unnatural excitement, if frequently repeated,
goes on increasing till the brain becomes incurably diseased.
Present space will not permit me to enter upon another branch of this
subject, viz.: the moral degradation and the perversion of natural,
unsophisticated, and wholesome theology, which these spiritual
delusions are generating.
I am no advocate for rectifying moral and intellectual evils by police
interference, or I should certainly recommend the bracing air of
Dartmoor for the mediums who publicly proclaim that their familiar
spirit “Katey” has lately translated a lady through a space of three
miles, and through the walls, doors, and ceiling of the house in which
a dark séance was being held, and placed her upon the table in the
midst of the circle so rapidly that the word “onions” she had just
written in her domestic inventory was not yet dried when the lights
were brought and she was found there.
This “lady,” which her name is Guppy, is, of course, another
professional medium, and yet there are people in London who gravely
believe this story, and also the appendix, viz.: that another member
of the mediumistic firm, finding that Mrs. G. was very incompletely
dressed, and much abashed thereby, was translated by the same spirit,
Katey, to her house and back again through the door-panel to fetch
proper garments. If I could justify the apprehension and imprisonment
of poor gipsy fortune-tellers, I certainly should advocate the close
confinement of Mrs. Guppy and her male associates, and thus afford
the potent spirit, Katey, an opportunity of further manifestation by
translating them through the prison walls and back to Lamb’s Conduit
Street.
(_The above letter appeared in the “Birmingham Morning News” of July
18, 1871; the following on November 15. It refers to an article in the
“Quarterly Review” of October, 1871._)
The interest excited by Mr. Crookes’s investigations on Psychic Force
is increasing; the demand for the “Quarterly Review” and the “Quarterly
Journal of Science” is so great that Mudie and other proprietors of
lending libraries have largely increased their customary supplies, and
are still besieged with further excess of demand. Not only borrowers,
but purchasers also are supplied with difficulty. I yesterday received
a post-card from a bookseller, inscribed as follows: “Cannot get a
‘Quarterly Review’ in the City, so shall be unable to send it to you
until to-morrow.” I have waited three days, and am now obliged to go to
the reading-room to make my quotations.
There is good and sufficient reason for this, independently of the
absence of Parliamentary and war news, and the dearth of political
revolutions. Either a new and most extraordinary natural force has
been discovered, or some very eminent men specially trained in
rigid physical investigation have been the victims of a marvelous,
unprecedented, and inexplicable physical delusion. I say unprecedented,
because, although we have records of many popular delusions of similar
kind and equal magnitude, and speculative delusions among the learned,
I can cite no instance of skillful experimental experts being utterly
and repeatedly deceived by the mechanical action of experimental test
apparatus carefully constructed and used by themselves.
As the interest in the subject is rapidly growing, my readers will
probably welcome a somewhat longer gossip on this than I usually devote
to a single subject.
Such an extension is the more demanded as the newspaper and magazine
articles which have hitherto appeared have, for the most part, by
following the lead of the “Quarterly Review,” strangely muddled the
whole subject, and misstated the position of Mr. Crookes and others. In
the first place, all the writers who follow the “Quarterly” omit any
mention or allusion to Mr. Crookes’s preliminary paper published in
July, 1870, which has a most important bearing on the whole subject, as
it expounds the object of all the subsequent researches.
Mr. Crookes there states that “Some weeks ago the fact that I was
engaged in investigating Spiritualism, so-called, was announced in
a contemporary (the “Athenæum”), and in consequence of the many
communications I have since received, I think it desirable to say a
little concerning the investigations which I have commenced. Views
or opinions I cannot be said to possess on a subject which I do not
profess to understand. I consider it the duty of scientific men, who
have learned exact modes of working, to examine phenomena which attract
the attention of the public, in order to confirm their genuineness, or
to explain, if possible, the delusions of the honest, and to expose the
tricks of the deceivers.”
He then proceeds to state the case of Science _versus_ Spiritualism
thus:—“The Spiritualist tells of bodies weighing 50 or 100 lbs. being
lifted up into the air without the intervention of any known force;
but the scientific chemist is accustomed to use a balance which will
render sensible a weight so small that it would take ten thousand of
them to weigh one grain; he is, therefore, justified in asking that a
power, professing to be guided by intelligence, which will toss a heavy
body to the ceiling, shall also cause his delicately-poised balance
to move under test conditions.” “The Spiritualist tells of rooms and
houses being shaken, even to injury, by superhuman power. The man of
science merely asks for a pendulum to be sent vibrating when it is in
a glass-case, and supported on solid masonry.” “The Spiritualist tells
of heavy articles of furniture moving from one room to another without
human agency. But the man of science has made instruments which will
divide an inch into a million parts, and he is justified in doubting
the accuracy of the former observations, if the same force is powerless
to move the index of his instrument one poor degree.” “The Spiritualist
tells of flowers with the fresh dew on them, of fruit, and living
objects being carried through closed windows, and even solid brick
walls. The scientific investigator naturally asks that an additional
weight (if it be only the 1000th part of a grain) be deposited on one
pan of his balance when the case is locked. And the chemist asks for
the 1000th part of a grain of arsenic to be carried through the sides
of a gas tube in which pure water is hermetically sealed.”
These and other requirements are stated by Mr. Crookes, together with
further exposition of the principles of strict inductive investigation,
as it should be applied to such an inquiry. A year after this he
published an account of the experiments, which I described in a former
letter, and added to his own testimony that of the eminent physicist
and astronomer, Dr. Huggins and Serjeant Cox. Subsequently, that is, in
the last number of the “Quarterly Journal of Science,” he has published
the particulars of another series of experiments.
I will not now enter upon the details of these, but merely state that
the conclusions of Mr. Crookes are directly opposed to those of the
Spiritualists. He positively, distinctly, and repeatedly repudiates
all belief in the operations of the supposed spirits, or of any other
supernatural agency whatever, and attributes the phenomena he witnessed
to an entirely different organ, viz.: to the direct agency of the
medium. He supposes that a force analogous to that which the nerves
convey from their ganglionic centres to the muscles, in producing
muscular contraction, may by an effort of the will be transmitted to
external inanimate matter, in such a manner as to influence, in some
degree, its gravitating power, and produce vibratory motion. He calls
this the _psychic force_.
Now, this is direct and unequivocal _anti_-spiritualism. It is
a theory set up in opposition to the supernatural hypotheses of
the Spiritualists, and Mr. Crookes’s position in reference to
Spiritualism is precisely analogous to that of Faraday in reference to
table-turning. For the same reasons as those above-quoted, the great
master of experimental investigation examined the phenomena called
table-turning, and he concluded that they were due to muscular force,
just as Mr. Crookes concludes that the more complex phenomena he has
examined are due to psychic force.
Speaking of the theories of the Spiritualists, Mr. Crookes, in his
first paper (July, 1870), says: “The pseudo-scientific Spiritualist
professes to know everything. No calculations trouble his serenity;
no hard experiments, no laborious readings; no weary attempts to
make clear in words that which has rejoiced the heart and elevated
the mind. He talks glibly of all sciences and arts, overwhelming the
inquirer with terms like ‘electro-biologise,’ ‘psychologise,’ ‘animal
magnetism,’ etc., a mere play upon words, showing ignorance rather than
understanding.” And further on he says: “I confess that the reasoning
of some Spiritualists would almost seem to justify Faraday’s severe
statement—that many dogs have the power of coming to more logical
conclusions.”
I have already referred to the muddled misstatement of Mr. Crookes’s
position by the newspaper writers, who almost unanimously describe him
and Dr. Huggins as two distinguished scientific men who have recently
been converted to Spiritualism. The above quotations, to which, if
space permitted, I might add a dozen others from either the first, the
second, or the third of Mr. Crookes’s papers, in which he as positively
and decidedly controverts the dreams of the Spiritualists, will show
how egregiously these writers have been deceived. They have relied
very naturally on the established respectability of the “Quarterly
Review,” and have thus deluded both themselves and their readers.
Considering the marvelous range of subjects these writers have to
treat, and the acres of paper they daily cover, it is not surprising
that they should have been thus misled in reference to a subject
carrying them considerably out of their usual track; but the offence of
the “Quarterly” is not so venial. It assumes, in fact, a very serious
complexion when further investigated.
The title of the article is “Spiritualism and its Recent Converts,”
and the “recent converts” most specially and prominently named are
Mr. Crookes and Dr. Huggins. Serjeant Cox is also named, but not as
a _recent_ convert; for the reviewer describes him as an old and
hopelessly infatuated Spiritualist. Knowing nothing of Serjeant
Cox, I am unable to say whether the reviewer’s very strong personal
statements respecting him are true or false—whether he really is “one
of the most gullible of the gullible,” etc., though I must protest
against the bad taste which is displayed in the attack which is made
upon this gentleman. The head and front of his offending consists in
having certified to the accuracy of certain experiments; and for having
simply done this, the reviewer proceeds, in accordance with the lowest
tactics of Old Bailey advocacy, to bully the witness, and to publish
disparaging personal details of what he did twenty-five years ago.
Dr. Huggins, who has had nothing further to do with the subject than
simply to state that he witnessed what Mr. Crookes described, and who
has not ventured upon one word of explanation of the phenomena, is
similarly treated.
The reviewer goes out of his way to inform the public that Dr. Huggins
is, after all, only a brewer, by artfully stating that, “like Mr.
Whitbread, Mr. Lassell, and other brewers we could name, Dr. Huggins
attached himself in the first place to the study of astronomy.” He
then proceeds to sneer at “such scientific amateurs,” by informing
the public that they “labor, as a rule, under a grave disadvantage,
in the want of that broad basis of scientific culture which alone can
keep them from the narrowing and pervertive influence of a limited
_specialism_.”
The reviewer proceeds to say that he has “no reason to believe that Dr.
Huggins constitutes an exception” to this rule, and further asserts
that he is justified in concluding that Dr. Huggins is ignorant of
“every other department of science than _the small subdivision of a
branch_ to which he has so meritoriously devoted himself.” Mark the
words, “small subdivision of a branch.” Merely a twig of the tree of
science is, according to this most unveracious writer, all that Dr.
Huggins has ever studied.
If a personal vindication were the business of this letter I could
easily show that these statements respecting the avocations, the
scientific training, and actual attainments of Dr. Huggins are gross
and atrocious misrepresentations; but Dr. Huggins has no need of my
championship; his high scientific position, the breadth and depth
of his general attainments, and the fact that he is not Huggins the
brewer, are sufficiently known to all in the scientific world, with the
exception of the “Quarterly” reviewer.
My object is not to discuss the personal question whether book-making
and dredging afford better or worse training for experimental inquiry
than the marvelously exact and exquisitely delicate manipulations of
the modern observatory and laboratory, but to protest against this
attempt to stop the progress of investigation, to damage the true
interests of science and the cause of truth, by throwing low libellous
mud upon any and everybody who steps at all aside from the beaten paths
of ordinary investigation.
The true business of science is the discovery of truth; to seek it
wherever it may be found, to pursue it through bye-ways as well as
highways, and, having found it, to proclaim it plainly and fearlessly,
without regard to authority, fashion, or prejudice. If, however, such
influential magazines as the “Quarterly Review” are to be converted
into the vehicles of artful and elaborate efforts to undermine the
scientific reputation of any man who thus does his scientific duty, the
time for plain speaking and vigorous protest has arrived.
My readers will be glad to learn that this is the general feeling of
the leading scientific men of the metropolis; whatever they may think
of the particular investigations of Mr. Crookes, they are unanimous in
expressing their denunciations of this article.
The attack upon Mr. Crookes is still more malignant than that upon Dr.
Huggins. Speaking of Mr. Crookes’s fellowship of the Royal Society, the
reviewer says: “We speak advisedly when we say that this distinction
_was conferred on him with considerable hesitation_;” and further that
“We are assured, on the highest authority, that he is regarded among
chemists as a specialist of specialists, _being totally destitute of
any knowledge of chemical philosophy, and utterly untrustworthy as
to any inquiry which requires more than technical knowledge for its
successful conduct_.”
The italics in these quotations are my own, placed there to mark
certain statements to which no milder term than that of falsehood is
applicable. The history of Mr. Crookes’s admission to the Royal Society
will shortly be published, when the impudence of the above statement
respecting it will be unmasked; and the other quotations I have
emphasized are sufficiently and abundantly refuted by Mr. Crookes’s
published works, and his long and able conduct of the _Chemical News_,
which is the only and the recognized British periodical representative
of chemical science.
If space permitted, I could go on quoting a long series of
misstatements of matters of fact from this singularly unveracious
essay. The writer seems conscious of its general character, for, in the
midst of one of his narratives, he breaks out into a foot-note, stating
that “_This_ is not an invention of our own, but a fact communicated
to us by a highly intelligent witness, who was admitted to one of Mr.
Crookes’s _séances_.” I have taken the liberty to emphasize the proper
word in this very explanatory note.
The full measure of the injustice of prominently thrusting forward
Dr. Huggins and Mr. Crookes as “recent converts” to Spiritualism will
be seen by comparing the reviewer’s own definition of Spiritualism
with Mr. Crookes’s remarks above quoted. The reviewer says that
“The fundamental tenet of the Spiritualist is the old doctrine of
communication between the spirits of the departed and souls of the
living.”
This is the definition of the reviewer, and his logical conclusion is
that Mr. Crookes is a Spiritualist because he explicitly denies the
fundamental tenet of Spiritualism, and Dr. Huggins is a Spiritualist
because he says nothing whatever about it.
If examining the phenomena upon which the Spiritualist builds his
“fundamental tenet,” and explaining them in some other manner,
constitutes conversion to Spiritualism, then the reviewer is a far more
thoroughgoing convert than Mr. Crookes, who only attempts to explain
the mild phenomena of his own experiments, while the reviewer goes
in for everything, including even the apotheosis of Mrs. Guppy and
her translation through the ceiling, a story which is laughed at by
Mr. Crookes and everybody else, excepting a few of the utterly crazed
disciples of the “Lamb’s Conduit Mediums” and the “Quarterly” reviewer,
who actually attempts to explain it by his infallible and ever
applicable physiological nostrum of “_unconscious cerebration_.”
No marvelous story either of ancient or modern date is too strong
for this universal solvent, which according to the reviewer, is the
sole and glorious invention of Dr. Carpenter. Space will not now
permit me to further describe “unconscious cerebration” and its vast
achievements, but I hope to find a corner for it hereafter.
I may add that the name of the reviewer is kept a profound secret, and
yet is perfectly well-known, as everybody who reads the article finds
it out when he reaches those parts which describe Dr. Carpenter’s
important physiological researches and discoveries.
MATHEMATICAL FICTIONS.
(BRITISH ASSOCIATION, 1871.)
The President’s inaugural address, which was going through the press
in London while being spoken in Edinburgh, has already been subject to
an unusual amount of sharp criticism. For my own part I cannot help
regarding it as one of the least satisfactory of all the inaugural
addresses that have yet been delivered at these annual meetings. They
have been of two types, the historical and the controversial; the
former prevailing. In the historical addresses the President has
usually made a comprehensive and instructive survey of the progress
of the whole range of science during the past year, and has dwelt
more particularly on some branch which from its own intrinsic merits
has claimed special attention, or which his own special attainments
have enabled him to treat with the greatest ability and authority. A
few Presidents have, like Dr. Huxley last year, taken up a particular
subject only, and have discussed it more thoroughly than they could
have done had they also attempted a general historical survey.
Every President until 1871 has scrupulously kept in view his judicial
position, and the fact that he is addressing, not merely a few learned
men, but the whole of England, if not the whole civilized world. They
have therefore clearly distinguished between the established and the
debatable conclusions of science, between ascertained facts and mere
hypotheses, have kept this distinction so plainly before their auditors
that even the most uninitiated could scarcely confound the one with the
other.
In Sir William Thomson’s address this desirable rule is recklessly
violated. He tells his unsophisticated audience that Joule was able
“to estimate the average velocity of the ultimate molecules or atoms”
of gases, and thus determined the atomic velocity of hydrogen “at 6225
feet per second at temperature 60 degs. Fahr., and 6055 feet at the
freezing point;” that “Clausius took fully into account the impacts
of molecules upon one another, and the kinetic energy of _relative_
motion of the matter constituting an individual atom;” and that “he
investigated the relation between their diameters, the number in a
given space, and the mean length of path from impact to impact, and
so gave the foundation for estimates of the absolute dimensions of
atoms.” Also that “Loschmidt, in Vienna, had shown, and not much later
Stoney, independently, in England, showed how to reduce from Clausius
and Maxwell’s kinetic theory of gases a superior limit to the number of
atoms in a given measurable space.”
The confiding auditor follows the President through further
disquisitions on the “superlatively grand question, what is the inner
mechanism of an atom?” and a minute and most definite description of
the “regular elastic vibrations” of “the ultimate atom of sodium,” of
the manner in which “any atom of gas, when struck and left to itself,
vibrates with perfect purity its fundamental note or notes,” and how,
“in a highly attenuated gas, each atom is very rarely in collision
with other atoms, and therefore is nearly at all times in a state
of true vibration,” while “in denser gases each atom is frequently
in collision;” besides, a great deal more, in all of which the
existence of these atoms is coolly taken for granted, and treated as a
fundamental established scientific fact.
After hearing all these oracular utterances concerning atoms, the
unsophisticated listener before mentioned will be surprised to learn
that no human being has ever seen an atom of any substance whatever;
that there exists absolutely no direct evidence of the existence of
any such atoms; that all these atoms of which Sir W. Thomson speaks so
confidently and familiarly, and dogmatically, are pure fragments of the
imagination.
He will be still further surprised to learn that the bare belief in the
existence of ultimate atoms as a merely hypothetical probability is
rejected by many of the most eminent of scientific men, and that among
those who have disputed the idea of the atomic constitution of matter,
is the great Faraday himself; that the question of the existence or
non-existence of atoms has recently been rather keenly discussed; and
that even on the question of the permissibility of admitting their
_hypothetical_ existence, scientific opinion is divided; and that such
a confident assumption of their existence as forms the basis of this
part of the President’s address is limited to only a small section of
mutually admiring transcendental mathematicians, Sir W. Thomson being
the most admired among them, as shown by the address of Professor Tait
to Section A.
It would have been perfectly legitimate and most desirable that Sir W.
Thomson should give the fullest and most favorable possible statement
of the particular hypotheses upon which he and his friends have
exercised their unquestionably great mathematical skill; but he should
have stated them as what they are, and for what they are worth, and
have clearly distinguished between such hypotheses and the established
facts of universally admitted science. Instead of doing this, he has
so mixed up the actual discoveries of indisputable facts with these
mere mathematical fancies as to give them both the semblance of equally
authoritative scientific acceptance, and thus, without any intention
to deceive anybody, must have misled nearly all the outside public who
have heard or read his address.
As these letters are mainly intended for those who are too much engaged
in other pursuits to study science systematically, and as most of the
readers of such letters will, as a matter of course, read the inaugural
address of the President of the British Association, I have accepted
the duty of correcting among my own readers the false impression which
this address may create.
As a set-off to the authoritative utterances of Sir W. Thomson on the
subject of atoms, I quote the following from an Italian philosopher,
who, during the present year, is holding in Italy a position very
similar to that of the annual President of our British Association.
Professor Cannizzaro has been elected by a society of Italian chemists
to act as this year’s director of a Chronicle of the Progress of
Chemical Science in Italy and abroad. In this capacity he has published
an inaugural treatise on the history of modern chemical theory, in the
course of which he thus speaks of the over-confident atomic theorists:
“They often speak on molecular subjects with as much dogmatic assurance
as though they had actually realized the ingenious fiction of
Laplace—had constructed a microscope by which they could detect the
molecules, and observe the number, forms, and arrangements of their
constituent atoms, and even determine the direction and intensity of
their mutual actions. Many of these things, offered at what they are
worth—that is, as hypotheses more or less probable, or as simple
artifices of the intellect—may serve, and really have served, to
collocate facts and incite to further investigations which, one day or
other, may lead to a true chemical theory; but, when perverted by being
stated as truths already demonstrated, they falsify the intellectual
education of the students of inductive science, and bring reproach on
the modern progress of chemistry.”
I translate the above from the first page of the first number of the
“Gazetta Chimica Italiana,” published at Palermo in January last. Had
these words been written in Edinburgh on the evening of the 2d of
August, in direct application to Sir William Thomson’s address, they
could not have described more pointedly and truly the prevailing vice
of this production. If space permitted, I could go further back and
quote the words of Lord Bacon, from the great text-book of inductive
philosophy, wherein he denounces the worship of all such intellectual
idols as our modern mathematical dreamers have created, and which they
so fervently adore.
An able writer in the _Daily News_ of last Friday is very severe upon
the biological portion of the President’s address, which contains a
really original hypothesis. Sir W. Thomson having stated that he is
“ready to adopt as an article of scientific faith, true through all
space and through all time, that life proceeds from life, and from
nothing but life,” asks the question, “How then did life originate
on the earth?” and tells us that “if a probable solution consistent
with the ordinary course of nature can be found, we must not invoke an
abnormal act of creative power.”
He assumes, with that perfect confidence in mathematical hypotheses
which is characteristic of the school of theorists which he leads,
that “tracing the physical history of the earth backwards, on strictly
dynamical principles, we are brought to a red-hot melted globe, on
which no life could exist;” and then, to account for the beginning
of life on our earth as it cooled down, he creates another imaginary
world, which he brings in collision with a second similar creation, and
thereby shatters it to fragments. He further imagines that one of these
imaginary broken-up worlds was already stocked with the sort of life
which he says can only proceed from life, and that from such a world
thus stocked and thus smashed “many great and small fragments carrying
seed and living plants and animals would undoubtedly be scattered
through space;” and that, “if at the present instant no such life
existed upon this earth, one such stone falling upon it might, by what
we blindly call _natural_ causes, lead to its becoming covered with
vegetation.”
The conclusion of this paragraph is instructively characteristic of
the philosophy of Sir William Thomson and his admirers. He says that
“the hypothesis that life originated on this earth through moss-grown
fragments of another world may seem _wild and visionary_; all I
maintain is that it is _not unscientific_.”
I have italicized the phrases which, put together, express the
philosophy of this school of modern manufacturers of mathematical
hypotheses. It matters not to them how “wild and visionary,” how
utterly gratuitous any assumption may be, it is not unscientific
provided it can be invested in formulæ, and worked out mathematically.
These transcendental mathematicians are struggling to carry philosophy
back to the era of Duns Scotus, when the greatest triumph of learning
was to sophisticate so profoundly an obvious absurdity that no ordinary
intellect could refute it.
Fortunately for the progress of humanity, there are other learned men
who firmly maintain that the business of science is the discovery and
teaching of simple sober truth.
The writer of the _Daily News_ article above referred to very
charitably suggests that Sir W. Thomson may be “poking fun at some of
his colleagues,” and compares the moss-grown meteorite hypothesis with
the Hindoo parable which explains the stability of the earth by stating
that it stands on the back of a monster tortoise, that the tortoise
rests upon the back of a gigantic elephant, which stands upon the shell
of a still bigger tortoise, resting on the back of another still more
gigantic elephant, and so on. Sir W. Thomson, of course, requires to
smash two more worlds in order to provide a moss-grown fragment for
starting the life upon the world which was broken up for our benefit,
and so on backwards _ad infinitum_.
WORLD-SMASHING.
Sir W. Thomson’s moss-grown fragment of a shattered world is not yet
forgotten. In the current number of the _Cornhill Magazine_ (January,
1872) it is very severely handled; the more severely, because the
writer, though treating the subject quite popularly, shows the
fallacy of the hypothesis, even when regarded from the point of view
of Sir W. Thomson’s own special department of study. That an eminent
mathematician should make a great slip when he ventures upon geological
or physiological ground is not at all surprising; it is, in fact, quite
to be expected, as there can be no doubt that the close study of _pure_
mathematics, by directing the mind to processes of calculation rather
than to phenomena, induces that sublime indifference to facts which has
characterized the purely mathematical intellect of all ages.
It is not surprising that a philosopher who has been engaged in
measuring the imaginary diameter, describing the imaginary oscillations
and gyrations of imaginary atoms, and the still more complex imaginary
behavior of the imaginary constituents of the imaginary atmospheres
by which the mathematical imagination has surrounded these imaginary
atoms, should overlook the vulgar fact that neither mosses nor other
vegetables, nor even their seeds, can possibly retain their vitality
when alternately exposed to the temperature of a blast furnace,
and that of two or three hundred degrees below the freezing point;
but it is rather surprising that the purely mathematical basis of
this very original hypothesis of so great a mathematician should be
mathematically fallacious—in plain language, a mathematical blunder.
In order to supply the seed-bearing meteoric fragment by which each
planet is to be stocked with life, it is necessary, according to Sir
W. Thomson, that two worlds—one at least flourishing with life—shall
be smashed; and, in order to get them smashed with a sufficient amount
of frequency to supply the materials for his hypothesis, the learned
President of the British Association has, in accordance with the
customary ingenuity of mathematical theorists, worked out the necessary
mathematical conditions, and states with unhesitating mathematical
assurance that—“It is as sure that collisions must occur between great
masses moving through space, as it is that ships, steered without
intelligence directed to prevent collision, could not cross and recross
the Atlantic for thousands of years with immunity from collision.”
The author of the paper in the _Cornhill_ denies this very positively,
and without going into the mathematical details, points out the basis
upon which it may be mathematically refuted—viz., that all such worlds
are traveling in fixed or regular orbits around their primaries or
suns, while each of these primaries travels in its own necessary path,
carrying with it all its attendants, which still move about him, just
as though he had no motion of his own.
These are the conclusions of Newtonian dynamics, the sublime simplicity
of which contrasts so curiously with the complex dreams of the modern
atom-splitters, and which make a further and still more striking
contrast by their exact and perfect accordance with actual and visible
phenomena.
Newton has taught us that there can be no planets traveling at random
like the Sir W. Thomson’s imaginary ships with blind pilots, and by
following up his reasoning, we reach the conclusion, that among all
the countless millions of worlds that people the infinity of space,
there is no more risk of collision than there is between any two of the
bodies that constitute our own solar system.
All the observations of astronomers, both before and since the
discovery of the telescope, confirm this conclusion. The long nightly
watching of the Chaldean shepherds, the star-counting, star-gauging,
star-mapping, and other laborious gazing of mediæval and modern
astronomers, have failed to discover any collision, or any motion
tending to collision, among the myriads of heavenly bodies whose
positions and movements have been so faithfully and diligently studied.
Thus, the hypothesis of creation which demands the destruction of two
worlds in order to effect the sowing of a seed, is as inconsistent with
sound dynamics as it is repugnant to common sense.
This subject suggests a similar one, which was discussed a few months
since at the Acadamy of Sciences of Paris. On January 30th last M. St.
Meunier read a paper on “The mode of rupture of a star, from which
meteors are derived.” The author starts with the assumption that
meteors have been produced by the rupture of a world, basing this
assumption upon the arguments he has stated in previous papers. He
discards altogether Sir W. Thomson’s idea of a collision between two
worlds, but works out a conclusion quite as melancholy.
He begins, like most other builders of cosmical theories, with the
hypothesis that this and all the other worlds of space began their
existence in a condition of nebulous infancy; that they gradually
condensed into molten liquids, and then cooled down till they obtained
a thin outside crust of solid matter, resting upon a molten globe
within; that this crust then gradually thickened as the world grew
older and cooled down by radiation. I will not stop to discuss this
nebular and cooling-down hypothesis at present, though it is but fair
to state that “I don’t believe a bit of it.”
Taking all this for granted—a considerable assumption—M. St. Meunier
reasons very ably upon what must follow, if we further assume that each
world is somehow supplied with air and water, and that the atmosphere
and the ocean of each world are limited and unconnected with those of
any other world, or with any general interstellar medium.
What, then, will happen as worlds grow old? As they cool down,
they must contract; the liquid inside can manage this without any
inconvenience to itself, but not so with the outer spherical shell of
solid matter. As the inner, or hotter part of this contracts, the cool
outside must crumple up in order to follow it, and thus mountain chains
and great valleys, lesser hills and dales, besides faults and slips,
dykes, earthquakes, volcanoes, etc., are explained.
According to M. St. Meunier, the moon has reached a more advanced
period of cosmical existence than the earth. She is our senior; and
like the old man who shows his gray hairs and tottering limbs to
inconsiderate youth, she shines a warning upon our gay young world,
telling her that—
Let her paint an inch thick, to this favor she must come
—that the air and ocean must pass away, that all the living creatures
of the earth must perish, and the desolation shall come about in this
wise.
At present, the interior of our planet is described as a molten fluid,
with a solid crust outside. As the world cools down with age, this
crust will thicken and crack, and crack again, as the lower part
contracts. This will form _rainures_, _i.e._, long narrow chasms, of
vast depth, which, like those on the moon, will traverse, without
deviation, the mountains, valleys, plains, and ocean-beds; the waters
will fall into these, and, after violent catastrophes, arising from
their boiling by contact with the hot interior, they will finally
disappear from the surface, and become absorbed in the pores of the
vastly-thickened earth-crust, and in the caverns, cracks, and chasms
which the rending contraction will open in the interior. These cavities
will continue to increase, will become of huge magnitude when the
outside crust grows thick enough to form its own supporting arch, for
then the fused interior will recede, and form mighty vaults that will
engulf not the waters merely, but all the atmosphere likewise.
At this stage the earth, according to M. St. Meunier, will be
a middle-aged world like the moon; but as old age advances the
contraction of the fluid, or viscous interior beneath the outside
solid crust will continue, and the _rainures_ will extend in length
and depth and width, as he maintains they are now growing in the moon.
This, he says, must continue till the centre solidifies, and then these
cracks will reach that centre, and the world will be split through in
fragments corresponding to the different _rainures_.
Thus we shall have a planet composed of several solid fragments held
together only by their mutual attractions, but the rotary movement
of these will, according to the French philosopher, become unequal,
as “the fragments present different densities, and are situated at
unequal distances from the centre; some will be accelerated, others
retarded; they will rub against each other, and grind away those
portions which have the weakest cohesion.” The fragments thus worn off
will, “at the end of sufficient time, girdle with a complete ring the
central star.” At this stage the fragments become real meteors, and
then perform all the meteoric functions excepting the seed-carrying of
Sir W. Thomson.
It would be an easy task to demolish these speculations, though not
within the space of one of my letters. A glance at the date of this
paper, and the state of Paris and the French mind at the time, may,
to some extent, explain the melancholy relish with which the Parisian
philosopher works out his doleful speculations. Had the French army
marched vigorously to Berlin, I doubt whether this paper would ever
have found its way into the “Comptes Rendus.” After the fall of Paris,
and the wholesale capitulation of the French armies, it was but natural
that a patriotic Frenchman, howsoever strong his philosophy, should
speculate on the collapse of all the stars, and the general winding-up
of the universe.
THE DYING TREES IN KENSINGTON GARDENS.
A great many trees have lately been cut down in Kensington Gardens, and
the subject was brought before the House of Commons at the latter part
of its last session. In reply to Mr. Ritchie’s question, Mr. Adam, the
then First Commissioner of Works, made explanations which, so far as
they go, are satisfactory—but the distance is very small. He states
that all who have watched the trees must have seen that their decay
“has become rapid and decided in the last two years,” that when the
vote for the parks came on many “were either dead or hopelessly dying,”
that in the more thickly planted portions of the gardens the trees were
dead and dying by hundreds, owing to the impoverished soil and the
terrible neglect of timely thinning fifty or sixty years ago.
Knowing the sensitiveness of the public regarding tree-cutting, Mr.
Adam obtained the co-operation of a committee of experts, consisting
of Sir Joseph Hooker, Mr. Clutton, and Mr. Thomas, “so distinguished
as a landscape gardener,” and the late First Commissioner of Works.
They had several meetings, and, as Mr. Adam informs us, “the result has
been a unanimous resolution that we ought to proceed at once to clear
away the dead and dying trees.” This is being done to the extent of “an
absolute clearance” in some places, and the removal of numerous trees
all over the gardens. We are further told that “the spaces cleared will
either be trenched, drained, and replanted, or will be left open, as
may appear best.” Mr. Adam adds that “the utmost care is being used in
the work; that not a tree is being cut that can properly be spared; and
that every effort will be made to restore life to the distinguished
trees that are dying.”
I have watched the proceedings in Kensington Gardens and also in Bushey
Park, and have considerable difficulty in describing the agricultural
vandalism there witnessed, and expressing my opinion on it, without
transgressing the bounds of conventional courtesy towards those who are
responsible. I do not refer to the cutting down of the dead and dying
trees, but to the proceedings by which they have been officially and
artificially killed by those who ought to possess sufficient knowledge
of agricultural chemistry to understand the necessary consequences of
their conduct.
About forty years have elapsed since Liebig taught to all who were able
and willing to learn that trees and other vegetables are composed of
two classes of material: 1st, the carbon and elements of water derived
from air and rain; and 2d, the nitrogenous and incombustible saline
compounds derived from the soil. The possible atmospheric origin of
some of the nitrogen is still under debate, but there is no doubt that
all which remains behind as incombustible ash, when we burn a leaf, is
so much matter taken out of the soil. Every scientific agriculturist
knows that certain crops take away certain constituents from the soil,
and that if this particular cropping continues without a replacing of
those particular constituents of fertility, the soil must become barren
in reference to the crop in question, though other crops demanding
different food may still grow upon it.
The agricultural vandalism that I have watched with so much vexation
is the practice of annually raking and sweeping together the fallen
leaves, collecting them in barrows and carts, and then carrying them
quite away from the soil in which the trees are growing, or should
grow. I have inquired of the men thus employed whether they put
anything on the ground to replace these leaves, and they have not
merely replied in the negative, but have been evidently surprised at
such a question being asked. What is finally done with the leaves I
do not know; they may be used for the flower-beds or sold to outside
florists. I have seen a large heap accumulated near to the Round Pond.
Now, the leaves of forest trees are just those portions containing the
largest proportion of ash; or, otherwise stated, they do the most in
exhausting the soil. In Epping Forest, in the New Forest, and other
forests where there has been still more “terrible neglect of timely
thinning,” the trees continue to grow vigorously, and have thus grown
for centuries; the leaves fall on the soil wherein the trees grow, and
thus continually return to it all they have taken away.
They do something besides this. During the winter they gradually decay.
This decay is a process of slow combustion, giving out just as much
heat as though all the leaves were gathered together and used as fuel
for a bonfire; but the heat in the course of natural decay is gradually
given out just when and where it is wanted, and the coating of leaves,
moreover, forms a protecting winter jacket to the soil.
I am aware that the plea for this sweeping-up of leaves is the demand
for tidiness; that people with thin shoes might wet their feet if they
walked through a stratum of fallen leaves. The reply to this is that
all reasonable demands of this class would be satisfied by clearing
the footpaths, from which nobody should deviate _in the winter time_.
Before the season for strolling in the grass returns, Nature will
have disposed of the fallen leaves. A partial remedy may be applied
by burning the leaves, then carefully distributing their ashes; but
this is after all a clumsy imitation of the natural slow combustion
above described, and is wasteful of the ammoniacal salts as well as
of the heat. The avenues of Bushey Park are not going so rapidly as
the old sylvan glories of Kensington Gardens, though the same robbery
of the soil is practiced in both places. I have a theory of my own
in explanation of the difference, viz., that the cloud of dust that
may be seen blowing from the roadway as the vehicles drive along the
Chestnut Avenue of Bushey Park, settles down on one side or the other,
and supplies material which to some extent, but not sufficiently,
compensates for the leaf-robbery.
The First Commissioner speaks of efforts being made to restore life to
the distinguished trees that are dying. Let us hope that these include
a restoration to the soil of those particular salts that have for
some years past been annually carted away from it in the form of dead
leaves, and that this is being done not only around the “distinguished”
trees, but throughout the gardens.
Any competent analytical chemist may supply Mr. Adam with a statement
of what are these particular salts. This information is obtainable by
simply burning an average sample of the leaves and analyzing their
ashes.
While on this subject I may add a few words on another that is
closely connected with it. In some parts of the parks gardeners may
be seen more or less energetically occupied in pushing and pulling
mowing-machines; and carrying away the grass which is thus cut. This
produces the justly admired result of a beautiful velvet lawn; but
unless the continuous exhaustion of the soil is compensated, a few
years of such cropping will starve it. This subject is now so well
understood by all educated gardeners that it should be impossible to
suppose it to be overlooked in our parks, as it is so frequently in
domestic gardening. Many a lawn that a few years ago was the pride
of its owner is now becoming as bald as the head of the faithful,
“practical,” and obstinate old gardener who so heartily despises the
“fads” of scientific theorists.
When natural mowing-machines are used, _i.e._, cattle and sheep, their
droppings restore all that they take away from the soil, minus the
salts contained in their own flesh, or the milk that may be removed. An
interesting problem has been for some time past under the consideration
of the more scientific of the Swiss agriculturists. From the mountain
pasturages only milk is taken away, but this milk contains a certain
quantity of phosphates, the restoration of which must be effected
sooner or later, or the produce will be cut off, especially now that so
much condensed milk is exported.
The wondrously rich soil of some parts of Virginia has been exhausted
by unrequited tobacco crops. The quantity of ash displayed on the
burnt end of a cigar demonstrates the exhausting character of tobacco
crops. That which the air and water supplied to the plant is returned
as invisible gases during combustion, but all the ash that remains
represents what the leaves have taken from the soil, and what should be
restored in order to sustain its pristine fertility.
The West India Islands have similarly suffered to a very serious extent
on account of the former ignorance of the sugar planters, who used
the canes as fuel in boiling down the syrup, and allowed the ashes of
those canes to be washed into the sea. They were ignorant of the fact
that pure sugar maybe taken away in unlimited quantities without any
impoverishment of the land, seeing that it is composed merely of carbon
and the elements of water, all derivable from air and rain. All that is
needed to maintain the perennial fertility of a sugar plantation is to
restore the stems and leaves of the cane, or carefully to distribute
their ashes.
The relation of these to the soil of the sugar plantations is precisely
the same as that of the leaves of the trees to the soil of Kensington
Gardens, and the reckless removal of either must produce the same
disastrous consequences.
THE OLEAGINOUS PRODUCTS OF THAMES MUD: WHERE THEY COME FROM AND WHERE
THEY GO.
Once upon a time—and not a very long time since—a French chemist left
the land of superexcellence, and crossed to the shores of foggy Albion.
He proceeded to Yorkshire, his object being to make his fortune. He
was so presumptuous as to believe that he might do this by picking up
something which Yorkshiremen threw away. That something was soapsuds.
His chemistry taught him that soap is a compound of fat and alkali,
and that if a stronger acid than that belonging to the fat is added to
soapsuds, the stronger acid will combine with the alkali and release
the fat, the which fat thus liberated will float upon the surface of
the liquid, and may then be easily skimmed off, melted together, and
sold at a handsome profit.
But why leave the beautiful France and desolate himself in dreary
Yorkshire merely to do this? His reason was, that the cloth workers
of Yorkshire use tons and tons of soap for scouring their materials,
and throw away millions of gallons of soapsuds. Besides this, there
are manufactories of sulphuric acid near at hand, and a large demand
for machinery grease just thereabouts. He accordingly bought iron
tanks, and erected works in the midst of the busiest centre of the
woolen manufacture. But he did not make his fortune all at once. On the
contrary, he failed to pay expenses, for in his calculations he had
omitted to allow for the fact that the soap liquor is much diluted, and
therefore he must carry much water in order to obtain a little fat.
This cost of carriage ruined his enterprise, and his works were offered
for sale.
The purchaser was a shrewd Yorkshireman, who then was a dealer in
second-hand boilers, tanks, and other iron wares. When he was about to
demolish the works, the Frenchman took him into confidence, and told
the story of his failure. The Yorkshireman said little, but thought
much; and having finally assured himself that the carriage was the
only difficulty, he concluded, after the manner of Mahomet, that if the
mountain would not come to him, he might go to the mountain; and then
made an offer of partnership on the basis that the Frenchman should do
the chemistry of the work, and that he (the Yorkshireman) should do the
rest.
Accordingly, he went to the works around, and offered to contract for
the purchase of all their soapsuds, if they would allow him to put up a
tank or two on their premises. This he did; the acid was added, the fat
rose to the surface, was skimmed off, and carried, _without the water_,
to the central works, where it was melted down, and, with very little
preparation, was converted into “cold-neck grease,” and “hot-neck
grease,” and used, besides, for other lubricating purposes. The
Frenchman’s science and skill, united with the Yorkshireman’s practical
sagacity, built up a flourishing business, and the grease thus made is
still in great demand and high repute for lubricating the rolling-mills
of iron works, and for many other kinds of machinery.
My readers need not be told that there are soapsuds in London as well
as in Yorkshire, and they also know that the London soapsuds pass
down the drains into the sewers. I may tell them that besides this
there are many kinds of acids also passed into London sewers, and that
others are generated by the decompositions there abounding. These acids
do the Frenchman’s work upon the London soapsuds, but the separated
fat, instead of rising slowly and undisturbed to form a film upon the
surface of the water, is rolled and tumbled amongst its multifarious
companion filth, and it sticks to whatever it may find congenial to
itself. Hairs, rags, wool, ravellings of cotton, and fibres of all
kinds are especially fraternal to such films of fat: they lick it up
and stick it about and amid themselves; and as they and the fat roll
and tumble along the sewers together, they become compounded and shaped
into unsavory balls that are finally deposited on the banks of the
Thames, and quietly repose in its hospitable mud.
But there is no peace even there, and the gentle rest of the fat
nodules is of short duration. The mud-larks are down upon them, in
spite of all their burrowing; they are gathered up and melted down. The
filthiest of their associated filth is thus removed, and then, and with
a very little further preparation, they appear as cakes of dark-colored
hard fat, very well suited for lubricating machinery, and indifferently
fit for again becoming soap, and once more repeating their former
adventures.
Those gentlemen of the British press whose brilliant imagination
supplies the public with their intersessional harvests of sensational
adulteration panics, have obtained a fertile source of paragraphs by
co-operating with the mud-larks in the manufacture of butter from
Thames mud.
The origin of these stories is traceable to certain officers of the
Thames police, who, having on board some of these gentlemen of the
press engaged in hunting up information respecting a body found in
the river, supplied their guests with a little supplementary chaff by
showing them a mud-lark’s gatherings, and telling them that it was raw
material from which “fine Dorset” is produced. A communication from
“Our Special Correspondent” on the manufacture of butter from Thames
mud accordingly appeared in the atrocity column on the following
morning, and presently “went the round of the papers.”
Although it is perfectly possible by the aid of modern chemical skill
to refine even such filth as this, and to churn it into a close
resemblance to butter, the cost of doing so would exceed the highest
price obtainable for the finest butter that comes to the London
market. A skillful chemist can convert all the cotton fibres that are
associated with this sewage fat into pure sugar or sugar-candy, but the
manufacture of sweetmeats from Thames mud would not pay any better than
the production of butter from the same source, and for the same reason.
Mutton-suet, chop-parings, and other clean, wholesome fat can be bought
wholesale for less than fivepence per pound. It would cost above three
times as much as this to bring the fat nodules of the Thames mud to as
near an approach to butter as this sort of fat. Therefore the Thames
mud-butter material would be three times as costly as that obtainable
from the butcher. While the supply of mutton-suet is so far in excess
of the butter-making demand that tons of it are annually used in the
North for lubricating machinery, we need not fear that anything less
objectionable—_i.e._, more costly to purify—will be used as a butter
substitute.
LUMINOUS PAINT.
The sun is evidently going out of fashion, and is more and more
excluded from “good society” as our modern substitute for civilization
advances. “Serve him right!” many will say, for behaving so badly
during the last two summers. The old saw, which says something about
“early to bed and early to rise” is forgotten: we take “luncheon”
at dinner-time, dine at supper-time, make “morning” calls and go to
“morning” concerts, etc., late in the afternoon, say “Good morning”
until 6 or 7 P.M.; and thus, by sleeping through the bright hours of
the morning, and waking up fully only a little before sunset, the
demand for artificial light becomes almost overwhelming. Not only do we
require this during a longer period each day, but we insist upon more
and more, and still more yet, during that period.
The rushlight of our forefathers was superseded by an exotic
luxury, the big-flame candle made of Russian tallow, with a wick
of Transatlantic cotton. Presently this luxurious innovation was
superseded by the “mould candle;” the dip was consigned to the kitchen,
and the bloated aristocrats of the period indulged in a _pair_ of
candlesticks, alarming their grandmothers by the extravagance of
burning two candles on one table. Presently the mould candle was
snuffed out by the composite; then came the translucent pearly paraffin
candle, gas light, solar lamps, moderator lamps, and paraffin lamps.
Even these, with their brilliant white flame from a single wick, are
now insufficient, and we have duplex and even triplex wicks to satisfy
our demand for glaring mockeries of the departed sun.
Some are still living who remember the oil lamps in Cheapside and
Piccadilly, and the excitement caused by the brilliancy of the new gas
lamps; but now we are dissatisfied with these, and demand electric
lights for common thoroughfares, or some extravagant combination of
concentric or multiplex gas-jets to rival it.
The latest novelty is a device to render darkness visible by capturing
the sunbeams during the day, holding them as prisoners until after
sunset, and then setting them free in the night. The principle
is not a new discovery; the novelty lies in the application and
some improvements of detail. In the “Boy’s Own Book,” or “Endless
Amusement,” of thirty or forty years ago, are descriptions of “Canton’s
phosphorus,” or “solar phosphori,” and recipes for making them. Burnt
oyster-shells or oyster-shells burnt with sulphur, was one of these.
Various other methods of effecting combination between lime or baryta
with sulphur are described in old books, the result being the formation
of more or less of what modern chemists call calcium sulphide and
barium sulphide (or otherwise sulphide of calcium or sulphide of
barium). These compounds, when exposed to the sun, are mysteriously
acted upon by the solar rays, and put into such a condition that their
atoms or molecules, or whatever else constitutes their substance,
are set in motion—in that sort of motion which communicates to the
surrounding medium the wavy tremor which agitates our optic nerve and
produces the sensation of light.
Until lately, this property has served no other purpose than puzzling
philosophers, and amusing that class of boys who burn their fingers,
spoil their clothes, and make holes in their mothers’ table-covers,
with sulphuric acid, nitric acid, and other noxious chemicals. The
first idea of turning it to practical account was that of making a sort
of enamel of one or the other of these sulphides, and using it as a
coating for clock-faces. A surface thus coated and exposed to the light
during the day becomes faintly luminous at night.
Anybody desirous of seeing the sort of light which it emits, may do so
very easily by purchasing an unwashed smelt from the fishmonger, and
allowing it to dry with its natural slime upon it, then looking at it
in the dark. A sole or almost any other fish will answer the purpose,
but I name the smelt from having found it the most reliable in the
course of my own experiments. It emits a dull, ghostly light, with very
little penetrating power, which shows the shape of the fish, but casts
no perceptible light on objects around.
Thus the phosphorescent parish-clock face, with non-phosphorescent
figures and hands, would look like a pale ghost of the moon with dark
figures round it, and dark hands stretching across, by which the
time of the night might possibly be discovered there or thereabouts.
This invention has already appeared in a great many paragraphs, but,
hitherto, upon very few clock-faces.
Recently it has assumed a more ambitions form—patented, of course. The
patentees claim an improved phosphorescent powder, which is capable
of being worked up with the medium of paints and varnishes, and thus
applied, not merely to clock-faces, but to the whole of the walls and
ceilings of any apartment. In this case the faintness of the light will
be in some degree compensated by the extent of phosphorescent surface,
and it is just possible that the sum total of the light emitted from
walls and ceiling may be nearly equal to that of one mould candle. If
so, it will have some value as a means of lighting powder magazines
and places for storage of inflammable compounds. It is stated that one
of the London Dock companies is about to use it for its spirit vaults;
also that the Admiralty has already tried the paint at Whitehall, and
has ordered two compartments of the _Comus_ to be painted with it, in
order to test its capability of lighting the dark regions of ironclad
ships.
This application can, however, only be limited to those parts which
receive a fair amount of light during the day, for unless the
composition first receives light, it is not able afterwards to emit it,
and this emission or phosphorescence only continues a few hours after
the daylight has passed away; five or six hours is the time stated.
A theatrical manager is said to be negotiating for the exclusive right
to employ this weird illumination for scenic purposes. The sepulchre
scene in “Robert le Diable,” or the incantation in “Der Freischutz,” or
“The Sorcerer,” might be made especially effective by its ghostly aid.
The name-plates of streets, and buoys at sea might be advantageously
coated with such a composition; and many other uses suggest themselves.
There are rival inventors, as a matter of course. The French patentees
claim the use of cuttle-fish bones, various sea-shells, etc., mixed
with pure lime, sulphur, and calcined sea-salt, besides sulphides of
calcium, barium, strontium, uranium, magnesium, or aluminium. They
also add phosphorus itself, though for what purpose is questionable,
seeing that this substance is only luminous during the course of its
oxidation or slow combustion, and after this has ended the resultant
phosphoric acid is no more luminous than linseed oil or turpentine. An
admixture of phosphorus might temporarily increase the luminosity of a
_sample_, but any conclusions based upon this would be quite delusive.
They also assert that electrical discharges passed through the paint
increase its luminosity. According to some enthusiasts, electricity
is to do everything; but these ladies and gentlemen omit to calculate
the cost of rousing and feeding this omnipotent giant. In this case
electrical machinery for stimulating the paint for anything outside of
lecture-table experiments or theatrical and other sensational displays,
would be a commercial absurdity.
The Americans, of course, are re-inventing in this direction, but Mr.
Edison has not yet appeared on the luminous-paint scene. If he does we
shall doubtless hear of something very brilliant, even though we never
see it. In the meantime we may safely hope that this application of an
old scientific plaything to useful purposes may become of considerable
utility, as it evidently opens a wide field for further investigation
and progressive improvement, by the application of the enlarged powers
which modern science places at the disposal of ingenious inventors. We
hope, for the sake of all concerned, that it will not fall into the
hands of professional prospectus manufacturers and joint-stock-company
mongers, and that the story of its triumphs will be told without any
newspaper exaggerations.
Since the above was written—in February, 1880—I have tested
this luminous paint (Balmain’s patent). Practically, I find it
unsatisfactory. In the first place, its endurance is far shorter
than is stated. It begins to fade almost immediately the light is
withdrawn, and in the course of an hour or two it is, for all practical
use—though not absolutely—extinguished. Besides this it emits a very
unpleasant odor painfully resembling sewage and sulphureted hydrogen.
This is doubtless due to the sulphur compound, but is, I have no doubt,
quite harmless in spite of its suggestions.
THE ORIGIN AND PROBABLE DURATION OF PETROLEUM.
In spite of the enormous quantities of mineral oil that are
continuously drawn from the earth, and the many places from which it
may thus be drawn, geologists are still puzzled to account for it. If
it were commonly associated with coal the problem of its origin would
be solved at once. We should then be satisfied that natural mineral
oil is produced in the same manner as the artificial product, _i.e._,
by the heating and consequent distillation of certain kinds of coal or
of bituminous shales; but, as a matter of fact, it is but rarely that
petroleum is found in the midst of coal seams, though it is sometimes
so found.
I visited, some years ago, a coal-mine in Shropshire, known as “the
tarry pit,” thus named on account of the large quantity of crude
mineral oil of a rather coarse quality that exuded from the strata
pierced by the shaft. It ran down the sides of the shaft, filled the
“sumph” (_i.e._, the well at the bottom of the shaft in which the water
draining from the mine should accumulate for pumping), and annoyed the
colliers so seriously that they refused to work in the mine unless
the nuisance were abolished. It was abolished by “tubbing” the shaft
with an oil-proof lining built round that part from which the oil
issued. The “tar” as the crude oil was called, was then pumped out of
the sumph, and formed a pool which has since been filled up by the
_débris_ of the ordinary mine workings.
A publican in the Black Country of South Staffordshire discovered an
issue of inflammable vapor in his cellar, collected it by thrusting a
pipe into the ground, and used it for lighting and warming purposes, as
well as an attraction to customers.
These and other cases that might be cited, although exceptional, are of
some value in helping us to form a simple and rational theory of the
origin of this important natural product. They prove that mineral oil
_may_ be produced in connection with coal seams and apparently from the
coal itself. A sound theory of the origin of petroleum is of practical
as well as theoretical value, inasmuch as the very practical question
of the probable permanency of supply depends entirely on the nature of
the origin of that supply. Some very odd theories have been put forth,
especially in America.
Seeing that petroleum is commonly found associated with sandstone and
limestone, especially in cavities of the latter, it has been supposed
that these minerals somehow produce it. Turning back to the _Grocer_
for April 18, 1872, I find some speculations of this kind quoted from
the _Petroleum Monthly_. The writer sets aside altogether, as an
antiquated and exploded fallacy, the idea that petroleum is produced
from coal, and maintains “that petroleum is mainly produced from,
or generated through, limestone,” and argues that the generation of
petroleum by such rocks is a continuous process, from the fact that
exhausted wells have recovered after being abandoned, his explanation
being “that the formerly abandoned territory was given up because the
machinery for extracting petroleum from the earth exceeded in its
power of exhausting the fluid the generative powers by which it is
produced;” these generative powers somehow residing in the limestone
and sandstone, but how is not specified.
Some writers have, however, gone a little further toward answering the
question of how limestone may generate petroleum. They have pointed
to the fossilized remains of animals, their shells, etc., existing
in the limestone, and have supposed that the animal matter has been
distilled, and has thus formed the oil.
If such a process could be imitated artificially by distilling some of
the later deposits of similar fossil character this theory would have a
better basis, or even if a collection of oysters, mussels, or any other
animal matters could by distillation be shown to produce an oil similar
to petroleum.
The contrary is the case. We may obtain oil from such material, but it
is utterly different from any kind of mineral oil, while, on the other
hand, by distilling natural bituminous shales, or cannel coal, or peat,
we obtain a crude oil almost identical with natural petroleum, and the
little difference between the two is perfectly accounted for by the
greater rapidity of our methods of distillation as compared with the
slow natural process. We may go on approximating more and more nearly
to the natural petroleum by distilling more and more slowly. As it
is, the refined products of the natural and artificial oil which is
commercially distilled in Scotland, are scarcely distinguishable—some
of them are not at all distinguishable—the solid paraffin, for
example. I now offer my own theory of the origin of oil springs.
To render this the more intelligible, let us first consider the
origin of ordinary water springs. St. Winifred’s Well, at Holywell,
in Flintshire, maybe taken as an example, not merely on account of
its magnitude, but because it is quite typical, and is connected with
limestone and sandstone in about the same manner as are the petroleum
wells of Pennsylvania.
Here we have a wondrous uprush of water just between the sandstone
and mountain limestone rocks, which amounts to above twenty tons per
minute, and flows down to the Dee, a small river turning several
water-mills. It is certain that all this water is not generated either
by the limestone or the sandstone from which it issues, nor can it be
all “generated” on the spot. The true explanation of its origin is
simple enough.
The mountain limestone underlies the coal measures and crops up
obliquely at Holywell; against this oblique subterranean wall of
compact rock impermeable to water, abuts a great face of down-sloping
strata of porous sandstone and porous shales. These porous rocks
receive the rain which falls on the slopes of the Hope Mountain and
other hills which they form; this water sinks into the millstone grit
of these hills and percolates downwards until it reaches the limestone
barrier, into which it cannot penetrate.
It here accumulates as a subterranean reservoir which finds an outlet
at a convenient natural fissure, and, as the percolation is continuous,
the spring is a constant one. Some of the water travels many miles
underground before it thus escapes. Hundreds of other smaller instances
might be quoted, the above being the common history of springs which
start up whenever the underground waters that flow through porous
rocks or soil meet with compact rocks or impermeable clay, and thus,
being able to proceed no further downwards, accumulate and produce an
overflow which we call a “spring.”
If water can thus travel underground, why not oil?
Although the oil springs or oil wells are not immediately above or
below coal seams, they are all within “measurable distance” of great
coal formations—the oil territory of Pennsylvania is, in fact,
surrounded by coal, some of it anthracite, which is really a coke, such
as would be produced if we artificially distilled the hydrocarbons from
coal, and then compressed the residue, as the anthracite has certainly
been pressed by the strata resting upon it.
The rocks in immediate contact and proximity to coal seams—“the coal
measures,” as they are called—are mostly porous, some of them very
porous, and thus if at any period of the earth’s long history a seam
of coal became heated, as we know so many strata are, and have been
heated, a mineral oil would certainly be formed, would first permeate
the porous rocks as vapor, then be condensed and make its way through
them, following their “dip” or inclination until it reached a barrier
such as the limestone forms.
It would thus in after-ages be found, not among the coal where it was
formed, but at the limestone or other impermeable rock by which its
further percolation was arrested.
This is just where it actually is found.
Limestone, although not porous like shales and sandstones, is specially
well adapted for storing large subterranean accumulations, on account
of the great cavities to which it is liable. Nearly all the caverns in
this country, in Ireland where they abound, in America, and other parts
of the world, are in limestone rocks; they are especially abundant
in the “carboniferous limestone” which underlies the coal measures,
and this is explained by the fact that limestone may be dissolved by
rain-water that has oozed through vegetable soil or has soaked fallen
leaves or other vegetable matter, and thereby become saturated with
carbonic acid.
Where the petroleum finds a crevice leading to such cavities it must
creep through it and fill the space, thereby forming one of the
underground reservoirs supplying those pumping wells that have yielded
such abundance for a while and then become dry. But if this theory is
correct it does not follow that the drying of such a well proves a
final stoppage of the supply, for if the cavity and crevice are left,
more oil may ooze into the crevice and flow into the cavity, and this
may continue again and again throughout the whole oil district so long
as the surrounding feeders of permeable strata continue saturated, or
nearly so. The magnitude of these feeding grounds may far exceed that
of the district wherein the springs occur, or where profitable wells
may be sunk, seeing that the localizing of profitable supply depends
mainly on the stoppage of further oozing away by the action of the
impermeable barrier.
A well sunk into the oozing strata itself would receive a very small
quantity, only that which, in the course of its passage came upon
the well sides, while at the junction between the permeable and the
impermeable rocks the accumulation may include all that reached the
whole surface of such junction or contact—many square miles.
To test this theory thoroughly it would be necessary to make borings,
not merely at the wells, but in their neighborhood, where the porous
rocks dip towards the limestone, and to bring up sample cores of these
porous rocks, and carefully examine them. Dr. Sterry Hunt has done this
in the oil-yielding limestone rocks of Chicago, but not in those of the
nearest coal-measures.
As the oil industry of America is of such great national importance, an
investigation of this kind is worthy of the energies of the American
Government geologists. It would throw much light on the whole subject,
and supply data from which the probable duration of the oil supply
might be approximately calculated.
Such an investigation might even do more than this. By proving the
geological conditions upon which depend the production of petroleum
springs, new sources may be discovered, just as new coal-seams have
been discovered, in accordance with geological prediction, or as the
practical discovery of the Austrian gold-fields was so long preceded
by Sir Roderick Murchison’s theoretical announcement of their probable
existence.
When the “kerosene wells” were first struck, the speculations
concerning their probable permanency were wild and various. Some
maintained that it was but a spurt, a freak of nature limited to a
narrow locality, and would soon be over; others asserted forthwith that
American oil, like everything else American, was boundless. Neither
had any grounds for their assertions, and therefore made them with the
usual boldness of mere dogmatism.
Then came a period of scare, started by the fact that wells which at
first spouted an inflammable mixture of oil and vapor high into the
air soon became quiescent, and from “spouting wells” became “flowing
wells,” merely pouring out on the surface a small stream at first,
which gradually declined to a dribble, and finally ceased to flow at
all. Even those that started modestly as flowing wells did the latter,
and thus appeared to become exhausted.
This exhaustion, however, was only apparent, as was proved by the
application of pumps, which drew up from wells, that had ceased either
to spout or flow, large and apparently undiminishing quantities of
crude oil.
Further observation and thought revealed the cause of these changes.
It became understood that the spouting was due to the tapping of a
rock-cavity containing oil of such varying densities and volatility
that some of it flew out as a vapor, or boiled at the mean temperature
of the air of the country or that of the surrounding rocks. Such being
the case, the cavity was filled with high-pressure oil-vapor straining
to escape. If the bore-hole tapped the crown or highest curve of the
roof of such an oil-cavern, it opened directly into the vapor there
accumulated, and the vapor itself rushed out with such force that a
pillar of fire was raised in the air if a light came within some yards
of the orifice. We are told of heavy iron boring-rods that were shot up
to wondrous heights—and we may believe these stories if we please.
If the bore-hole struck lower down, somewhere on the sloping sides or
in the shallow lower branches of the oil-cavern, it dipped at once into
liquid oil, and this oil, being pressed by the elastic vapor of the
upper part, was forced up as a jet of spouting oil.
In either case these violent proceedings soon came to an end, for as
the vapor or oil poured out, the space above the oil-level where the
vapor had been confined was increased, and its pressure diminished,
till at last it barely sufficed to raise the oil to the surface, and
afterwards failed to do that.
It is quite clear from this that the supplies are not “inexhaustible.”
The quantity of vapor having been limited, there must also be a
limit to the quantity of oil giving off this vapor; the space in the
oil-cavern occupied by this vapor having been limited, there must be
a limit to the space occupied by the oil. The quantity of oil may be
ten times, a hundred times, a thousand times, or ten thousand times,
greater than that of the vapor, but in either or any case it must come
to an end at last, sooner later.
If there were but a few wells here and there, as at other similar
places, such as Rangoon, the Persian oil-wells, etc., the pumping
might continue for centuries and centuries; but this is not the case
in America. The final boundaries of the oil-bearing strata may not
yet have been reached; but so far as they are known they are riddled
through and through, and pumped in every direction, so that the end
must come at last, though with our present knowledge we cannot say
_when_.
We can, however, say _how_ it must come. It will not be a sudden
stoppage, but a gradual exhaustion indicated by progressive diminution
of supply. We shall not be suddenly deprived of this important source
of light and cheerfulness; but we may at any time begin to feel the
pinch of scarcity and consequent rise of price. This rise of price will
check the demand, and bring forth other supplies from sources that now
cannot be profitably worked on account of the cheapness of American
petroleum.
Many of the countries now largely supplied from America have
oil-springs of their own, which a rise of price will speedily bring
into paying operation.
We have nothing to fear. The fact that in spite of the ruinous prices
that have recently prevailed the Scotch oil-makers continue to exist
at all, shows us what they may do with a rise of even a few pence per
gallon. The thickness and area of the dark shales from which their oil
is distilled are so great that their exhaustion is very far remote
indeed. The Americans have similar shales to fall back upon when the
spontaneous product ceases to flow, but they are quite incapable of
competing with us at home on equal terms—that is, when both have to
obtain the oil as a manufactured product of artificial distillation.
If anything like moderation were possible in America, the first
indications of scarcity would be followed by some economy in working;
but this is not to be anticipated. It is more likely that the first
rise of prices will attract additional speculation, and the sinking
of more wells in the hope of large profits, and this of course will
shorten the period of gradual exhaustion, the commencement of which
may, for aught we know, be very near at hand, especially if the new
projects for using petroleum as furnace fuel under steam boilers, and
for the smelting, puddling, and founding of iron and other metals, are
carried out as they may be so easily at present prices, and with the
aid of pipe-lines to carry the crude or refined oil from the wells to
any part of the great American continent where it may be required in
large quantities.
The old story of the goose that laid the golden eggs seems to be in
course of repetition in Transatlantic Petrolia.
* * * * *
Since the above was written I have received from Dr. Sterry Hunt a
copy of his interesting “Chemical and Geological Essays,” in one of
which he expounds a theory of the origin of petroleum. He states that
it appears to him “that the petroleum, or rather the materials from
which it has been formed, existed in the limestone rocks from the time
of their first deposition,” and “that petroleum and similar bitumens
have resulted from a peculiar transformation of vegetable matters, or
in some cases of animal tissues analogous to these in composition.”
The objections on page 275 apply to the animal tissues of this theory,
and as regards the vegetable matter I think it fails from the want of
anything like an adequate supply in these limestone rocks.
THE ORIGIN OF SOAP.
A history of soap would be very interesting. Who invented it? When and
where did it first come into common use? How did our remote ancestors
wash themselves before soap was invented? These are historical
questions that naturally arise at first contemplation of the subject;
but, as far as we are aware, historians have failed to answer them. We
read a great deal in ancient histories about anointing with oil and the
use of various cosmetics for the skin, but nothing about soap.
These ancients must have been very greasy people, and I suspect
that they washed themselves pretty nearly in the same way as modern
engine-drivers clean their fingers, by wiping off the oil with a bit of
cotton-waste.
We are taught to believe that the ancient Romans wrapped themselves
round with togas of ample dimensions, and that these togas were
white. Now, such togas, after encasing such anointed oily skins,
must have become very greasy. How did the Roman laundresses or
launders—historians do not indicate their sex—remove this grease?
Historians are also silent on this subject.
A great many curious things were found buried under the cinders
of Vesuvius in Pompeii, and sealed up in the lava that flowed over
Herculaneum. Bread, wine, fruits, and other domestic articles,
including several luxuries of the toilet, such as pomades or
pomade-pots, and rouge for painting ladies’ faces, but no soap for
washing them. In the British Museum is a large variety of household
requirements found in the pyramids of Egypt, but there is no soap, and
we have not heard of any having been discovered there.
Finding no traces of soap among the Romans, Greeks, or Egyptians, we
need not go back to the pre-historic “cave men,” whose flint and bone
implements were found embedded side by side with the remains of the
mammoth bear and hyena in such caverns as that at Torquay, where Mr.
Pengelly has, during the last eighteen years, so industriously explored.
All our knowledge, and that still larger quantity, our ignorance, of
the habits of antique savages, indicate that solid soap, such as we
commonly use, is a comparatively modern luxury; but it does not follow
that they had no substitute. To learn what that substitute may probably
have been we may observe the habits of modern savages, or primitive
people at home and abroad.
This will teach us that clay, especially where it is found having
some of the unctuous properties of fuller’s-earth, is freely used for
lavatory purposes, and was probably used by the Romans, who were by
no means remarkable for anything approaching to true refinement. They
were essentially a nasty people, the habits of the poor being “cheap
and nasty;” of the rich, luxurious and nasty. The Roman nobleman did
not sit down to dinner, but sprawled with his face downwards, and took
his food as modern swine take theirs. At grand banquets, after gorging
to repletion, he tickled his throat in order to vomit and make room
for more. He took baths occasionally, and was probably scoured and
shampooed as well as oiled, but it is doubtful whether he performed any
intermediate domestic ablutions worth naming.
A refinement upon washing with clay is to be found in the practice once
common in England, and still largely used where wood fires prevail. It
is the old-fashioned practice of pouring water on the wood ashes, and
using the “lees” thus obtained. These lees are a solution of alkaline
carbonate of potash the modern name of potash being derived from the
fact that it was originally obtained from the ashes under the pot. In
like manner soda was obtained from the ashes of seaweeds and of the
plants that grow near the seashore, such as the _salsover soda_, etc.
The pot-ashes or pearl-ashes being so universal as a domestic
bi-product, it was but natural that they should be commonly used,
especially for the washing of greasy clothes, as they are to the
present day. Upon these facts we may build up a theory of the origin of
soap.
It is a compound of oil or fat with soda or potash, and would be formed
accidentally if the fat on the surface of the pot should boil over and
fall into the ashes under the pot. The solution of such a mixture if
boiled down would give us soft soap.
If oil or fat became mixed with the ashes of soda plants, it would
produce hard soap. Such a mixture would most easily be formed
accidentally in regions where the olive flourishes near the coast, as
in Italy and Spain for example, and this mixture would be Castile soap,
which is still largely made by combining refuse or inferior olive oil
with the soda obtained from the ashes of seaweed.
The primitive soap-maker would, however, encounter one difficulty—that
arising from the fact that the potash or soda obtained by simple
burning of the wood or seaweed is more or less combined with carbonic
acid, instead of being all in the caustic state which is required for
effective soap-making. The modern soap-maker removes this carbonic
acid by means of caustic lime, which takes it away from the carbonate
of soda or carbonate of potash by simple exchange—_i.e._, caustic
lime _plus_ carbonate of soda becoming caustic soda _plus_ carbonate
of lime, or carbonate of potash _plus_ caustic lime becoming caustic
potash _plus_ carbonate of lime.
How the possibility of making this exchange became known to the
primitive soap-maker, or whether he knew it at all, remains a mystery,
but certain it is that it was practically used long before the
chemistry of the action was at all understood. It is very probable
that the old alchemists had a hand in this.
In their search for the philosopher’s stone, the elixir of life, or
drinkable gold, and for the universal solvent, they mixed together
everything that came to hand, they boiled everything that was boilable,
distilled everything that was volatile, burnt everything that was
combustible, and tortured all their “simples” and their mixtures
by every conceivable device, thereby stumbling upon many curious,
many wonderful, and many useful results. Some of them were not
altogether visionary—were, in fact, very practical, quite capable of
understanding the action of caustic lime on carbonate of soda, and of
turning it to profitable account.
It is not, however, absolutely necessary to use the lime, as the soda
plants when carefully burned in pits dug in the sand of the sea-shore
may contain but little carbonic acid if the ash is fluxed into a hard
cake like that now commonly produced, and sold as “soda ash.” This
contains from three to thirty per cent of carbonate, and thus some
samples are nearly caustic, without the aid of lime.
As cleanliness is the fundamental basis of all true physical
refinement, it has been proposed to estimate the progress of
civilization by the consumption of soap, the relative civilization of
given communities being numerically measured by the following operation
in simple arithmetic:—Divide the total quantity of soap consumed in
a given time by the total population consuming it, and the quotient
expresses the civilization of that community.[28]
The allusion made by Lord Beaconsfield, at the Lord Mayor’s dinner in
1879, to the prosperity of our chemical manufactures was a subject
of merriment to some critics, who are probably ignorant of the fact
that soap-making is a chemical manufacture, and that it involves many
other chemical manufactures, some of them, in their present state, the
results of the highest refinements of modern chemical science.
While the fishers of the Hebrides and the peasants on the shores of the
Mediterranean are still obtaining soda by burning seaweed as they did
of old, our chemical manufacturers are importing sulphur from Sicily
and Iceland, pyrites from all quarters, nitrate of soda from Peru and
the East Indies, for the manufacture of sulphuric acid, by the aid
of which they now make enormous quantities of caustic soda from the
material extracted from the salt mines of Cheshire and Droitwich. These
sulphuric acid works and these soda works are among the most prosperous
and rapidly growing of our manufacturing industries, and their chief
function is that of ministering to soap-making, in which Britain is now
competing triumphantly with all the world.
By simply considering how much is expended annually for soap in
every decent household, and adding to this the quantity consumed in
laundries and by our woolen and cotton manufacturers, a large sum
total is displayed. Formerly, we imported much of the soap we used at
home; now, in spite of our greatly magnified consumption, we supply
ourselves with all but a few special kinds, and export very large and
continually increasing quantities to all parts of the world; and if
the arithmetical rule given above is sound, the demand must steadily
increase as civilization advances.
OILING THE WAVES.
The recent gales have shown that if “Britannia rules the waves” her
subjects are very turbulent and costly. Our shipping interests are
now of enormous magnitude, and they are growing year by year. We
are, in fact, becoming the world’s carriers on the ocean, and are
thus ruling the waves in a far better sense than in the old one. Our
present mercantile rule adds to the wealth of our neighbors instead of
destroying it, as under the old warlike rule.
Everything concerning these waves is thus of great national interest,
the loss of life and sacrifice of wealth by marine casualties being so
great. Some curious old stories are extant, describing the exploits
of ancient mariners in stilling the waves by pouring oil upon them.
Both Plutarch and Pliny speak of it as a regular practice. Much later
than this, in a letter dated Batavia, January 5, 1770, written by M.
Tengragel, and addressed to Count Bentinck, the following passage
occurs:—“Near the islands Paul and Amsterdam we met with a storm,
which had nothing particular in it worthy of being communicated to
you, except that the captain found himself obliged, for greater safety
in wearing the ship, to pour oil into the sea to prevent the waves
breaking over her, which had an excellent effect, and succeeded in
preserving us. As he poured out but a little at a time, the East
India Company owes, perhaps, its ship to only six demi-aumes of olive
oil. I was present on deck when this was done, and should not have
mentioned this circumstance to you, but that we have found people here
so prejudiced against the experiment as to make it necessary for the
officers on board and myself to give a certificate of the truth on this
head, of which we made no difficulty.”
The idea was regarded with similar prejudice by scientific men
until Benjamin Franklin had his attention called to it, as he thus
narrates:—“In 1757, being at sea in a fleet of ninety-six sail,
bound for Louisbourg, I observed the wakes of two of the ships to be
remarkably smooth, while all the others were ruffled by the wind,
which blew fresh. Being puzzled with the differing appearance, I at
last pointed it out to the captain, and asked him the meaning of it.
‘The cooks,’ said he, ‘have, I suppose, been just emptying their
greasy water through the scuppers, which has greased the sides of the
ships a little.’ And this answer he gave me with an air of some little
contempt, as to a person ignorant of what everybody else knew. In my
own mind, I first slighted the solution, though I was not able to think
of another.”
Franklin was not a man to remain prejudiced; he accordingly
investigated the subject, and the results of his experiments, made upon
a pond on Clapham Common, were communicated to the Royal Society. He
states that after dropping a little oil on the water, “I saw it spread
itself with surprising swiftness upon the surface, but the effect of
smoothing the waves was not produced; for I had applied it first upon
the leeward side of the pond, where the waves were largest, and the
wind drove my oil back upon the shore. I then went to the windward
side, where they began to form; and there the oil, though not more than
a teaspoonful, produced an instant calm over a space several yards
square, which spread amazingly, and extended itself gradually till it
reached the lee side, making all that quarter of the pond (perhaps half
an acre) as smooth as a looking-glass.”
Franklin made further experiments at the entrance of Portsmouth Harbor,
opposite the Haslar Hospital, in company with Sir Joseph Banks, Dr.
Blagden, and Dr. Solander. In these experiments the waves were not
destroyed, but were converted into gentle swelling undulations with
smooth surfaces. Thus it appeared that the oil destroys small waves,
but not large billows.
Franklin’s explanation is, “that the wind blowing over water covered
with a film of oil cannot easily _catch_ upon it, so as to raise the
first wrinkles, but slides over it and leaves it smooth as it finds it.”
Further investigations have since been made which confirm this theory.
The first action of the wind in blowing up what the sailors call “a
sea,” is the production of a ripple on the surface of the water. This
ripple gives the wind a strong hold, and thus larger waves are formed,
but on these larger there are smaller waves, and on these smaller waves
still smaller ripples. All this roughness of surface goes on helping
the wind, till at last the mightiest billows are formed, which then
have an oscillation independent of the wind that formed them. Hence
the oil cannot at once subdue the great waves that are already formed,
but may prevent their formation if applied in time. Even the great
waves are moderated by the oil stopping the action of the wind which
sustains and augments them.
Quite recently, Captain David Gray made some experiments at the north
bar of Peterhead, where a very heavy surf breaks over in rough weather.
On a rough day he dropped a bottle full of oil into the sea. The oil
floating out of the bottle, converted the choppy waves over a large
area “into an expanse of long undulating rollers, smooth and glassy,
and so robbed of all violence that a small open boat could ride on them
in safety.”
This result is quite in accordance with what we are told respecting the
ancient practice of the fishermen of Lisbon, who were accustomed to
empty a bottle of oil into the sea when they found on their return to
the river that there was a dangerous surf on the bar, which might fill
their boats in crossing it.
As regards Peterhead, it is proposed to lay perforated pipes across
the mouth of the harbor, and to erect tanks from which these pipes
may be supplied with oil, and thus pour a continuous and widely
distributed stream into the sea in bad weather. The scheme was mooted
some time ago, but I am not aware whether it has yet been carried out.
Its success or failure must mainly be determined by the cost, and
this will largely depend upon the kind of oil that is used. A series
of well-conducted experiments upon the comparative areas protected
by different kinds of oil would be very interesting and practically
useful, for, until this has been ascertained, a proper selection cannot
be made. How long will it last? is another question.
I have frequently seen such tracks as Franklin observed out at sea, and
have climbed to the masthead in order to sight the ship that produced
them, without seeing any. Several of such smooth shining tracks have
been observed at the same time, but no ship visible, and this in places
where no sail has been seen for days before or after. The poet’s
description of “the trackless ocean” is by no means “founded on fact.”
The Plymouth Breakwater contains 3,369,261 tons of stone, and cost
the British Government a million and a half. The interest on this at
4 per cent amounts to 60,000_l._ per annum. If the above statements
are reliable, some of the wholesale oil merchants who read this might
contract to becalm a considerable area of the Channel for a smaller
amount.
Further experiments have been made at Peterhead since the above was
written. The following account, from the _Times_ of those made on
February 27, 1882, is interesting:
“On Monday the long-wished-for easterly gale to test the experiment
of throwing oil on the troubled waters reached Peterhead. It may be
mentioned that the harbor of Peterhead is singularly exposed, and
with an east or north-east gale is very dangerous of approach. Mr.
Shields, of Perth, has laid the oil apparatus to be used in quelling
the troubled waters. It consists of an iron pipe which conveys oil
and extends from a wooden house behind the seawall at Roanhead down
through a natural gullet in the rocks about 150 yards long and about
50 yards beyond the mouth of the gullet into about seven fathoms of
water; at this point the iron pipe is joined to a guttapercha pipe,
which extends across the harbor entrance outside the bar and is
perforated at distances 12½ yards apart. Through the guttapercha pipe
the oil reaches the sea. On Monday the wind was not so strong as to
make the experiment so complete as could have been wished; still,
there was a heavy swell. Early in the forenoon the pumps were put in
motion and the leakage space in the pipe filled; but unfortunately it
was found, soon after the oil began to rise to the surface of the bay,
that the supply in the cask had become exhausted, and those who were
conducting the experiment did not consider themselves at liberty to
order a fresh cask of oil without Mr. Shield’s sanction. But while the
experiment was only partial it was highly satisfactory. At the same
time, the film did not extend sufficiently far to prevent the waves
forming and curving to broken water. As soon, however, as they reached
the oil-covered neck the observers from the pier-head could easily
discern the influence at work. Waves which came in crested gradually
assumed the shape of undulating bodies of water, and, once formed, they
rolled unbroken towards the breakwater. On Wednesday morning there
was a heavy sea at the north breakwater. The oil valves were opened,
and immediately the effect was manifest. The waves, which had before
clashed with fury against the breakwater, assumed a rolling motion and
were quite crestless. Indeed, it was admitted that the oil had rendered
the entrance comparatively safe, _but the effect was not so abiding as
could have been wished_.”
As regards the want of duration there noted, I venture to make a
suggestion.
Oils vary so greatly in their rate of outspreading over water and the
character of the film they form, that some years ago Mr. Moffatt,
of Glasgow, proposed to use these differences as a test for the
adulterations of one kind of oil with other and cheaper kinds.
I made a number of experiments verifying some of his results.
From these it is evident that the duration of the becalming effect will
vary with different oils, and therefore further experiments upon these
difference should be made, in order to select that kind which is the
most effective, with due regard, of course, to cost.
The oil indicated by my experiments as combining permanency and
cheapness, and altogether the most suitable and attainable is the
“_dead oil_” refuse of the gas-works. This may be used in its crude and
cheapest condition.
ON THE SO-CALLED “CRATER NECKS” AND “VOLCANIC BOMBS” OF IRELAND.
A PAPER READ AT THE GEOLOGISTS’ ASSOCIATION, DECEMBER 6, 1878.
Mr. Hull, “Physical Geography and Geology of Ireland,” p. 68, under the
head of “Volcanic Necks and Basaltic Dykes,” says that “although the
actual craters and cones of eruption have been swept from the surface
of the country by the ruthless hand of time, yet the old “necks” by
which the volcanic mouths were connected with the sources of eruption
can occasionally be recognized; they sometimes appear as masses of hard
trap, columnar or otherwise, projecting in knolls or hills above the
upper surface of the sheets through which they pierce.”
In other cases, the “neck” consists of a great pipe choked up by bombs
and blocks of trap, more or less consolidated, bombs which have been
shot into the air and have fallen back again. He then refers to one
of these near Portrush, and proceeds to state that the rock on which
stands the ruined Castle of Dunluce, “is formed of bombs of all sizes
up to six feet in diameter, of various kinds of basalt, dolerite, and
amygdaloid firmly cemented, and presenting a precipitous face to the
sea.”
In a note dated September, 1877, Mr. Hull states that subsequent
examination, since the above was written, of the rock of Dunluce Castle
and the cliffs adjoining, has led him “to suspect that we have here,
instead of old volcanic necks, simply pipes, formed by the filtration
out of the chalk into which the basaltic masses have fallen and slipped
down, thus giving rise to their fragmental appearance.”
Further on (page 146) he describes without any sceptical comment, “the
remarkable mass of agglomerate made up (as on the southern flanks of
Slieve Gullion) of bombs of granite, which have been torn up from the
granite mass of the hills below, and blown through the throat of an old
crater.” Other geologists still adhere firmly to the bomb theory, some
ascribing the bombs to subaqueous rather than subaerial ejection.
Immediately under Dunluce Castle is a sea-worn cavern or tunnel, which
is about 40 or 50 feet high at its mouth, affording a fine section of
this curious conglomerate. The floor of the cavern which slopes upwards
from the sea is strewn with a beach of boulders. The resemblance
of this beach to those I had recently examined at the foot of the
boulder-clay cliffs of Galway Bay (and described in a paper read to the
British Association), suggested the explanation of the origin of the
rock I am about to offer.
In shape and size they are exactly like the Galway shore boulders,
those nearest the sea being the most rounded; higher up the slope,
where less exposed to wave action, they are subangular. They differ
from the Galway boulders in being chiefly basaltic instead of being
mainly composed of carboniferous limestone. Some of these at Dunluce
are granitic, and a few, if I am not greatly mistaken, are of
carboniferous limestone. I had not at hand the means of positively
deciding this.
Neither could I find any unquestionable examples of glacial striation
among them, though at the upper part I saw some lines on boulders that
were very suggestive of partially obliterated scratches.
On looking at the cavern walls surrounding me the theory so obviously
suggested by the boulders on the floor was strikingly confirmed by
their structure and general appearance. The imbedded “bombs” are
subangular, and of irregular shape and varying composition, and the
matrix of the rock is a brick-like material just such as would be
formed by the baking of boulder clay; the inference that I was looking
upon a bank or deposit of glacier drift that had been baked by volcanic
agency was irresistible.
I was unable to see on any part of the extensive section, or among the
fragments below, a single specimen of an unequivocal volcanic bomb;
no approach to anything like those described by Sir Samuel Baker in
his “Nile Tributaries of Abyssinia,” the miniature representatives
of which, ejected from the Bessemer converter, I have figured and
described in _Nature_, vol. 3, pp. 389 and 410, where Sir Samuel
Baker’s description is quoted.
I have witnessed the fall of masses of lava during a minor eruption of
an inner crater of Mount Vesuvius. These as they fell upon the ground
around me were flattened out into thin cakes. There was no approach
to the formation of subangular masses, like those displayed upon the
Dunluce cavern walls.
Some years ago a project for melting the basaltic rock known as “Rowley
Rag,” and casting it into moulds for architectural purposes was carried
out near Oldbury, and I had an opportunity of watching the experiment,
which was conducted on a large scale at great expense by Messrs. Chance.
It was found that if the basalt cooled rapidly it became a black
obsidian, and to prevent the formation of such brittle material, the
castings, and the moulds, which enclosed them, had to be kept at a
red-heat for some days, and very gradually cooled.[29]
It is physically impossible that lava ejected under water, in lumps no
larger than these boulders, could have the granular structure which
they display.
The fundamental idea upon which this bomb theory is based will not
bear examination. Such bombs could not have been shot into either air
or water and have fallen back again into the volcanic neck at any
other time than during an actual eruption; and at such time they could
not have remained where they fell, and have become embedded in any
such matrix as now contains them. True volcanic bombs and ordinary
spattering lumps of lava, are, as we know, flung obliquely out of
active craters, and distributed around, while those which are ejected
perpendicularly into the air and return are re-ejected, and finally
pulverized into volcanic dust if this perpendicular ejection and return
are continued long enough.
In the course of a rapid drive round the Antrim coast I observed other
examples of this peculiar conglomerate, and have reason to believe that
it is far more common than is generally supposed. I found it remarkably
well displayed at a place almost as largely visited as the Giant’s
Causeway, and where it nevertheless appears to have been hitherto
unnoticed, viz., Carrick-a-Rede, where the public car stops to afford
visitors an opportunity of examining or crossing the rope bridge, etc.
Here the whole formation is displayed in a manner that strikingly
illustrates my theory.
There is an overlying stream of basalt forming the surface of
the isolated rock, and this basalt rests directly upon a base of
conglomerate, having exactly the appearance that would result from the
slow baking of a mass of boulder clay.
The sea gully that separates the insular rock from the mainland
displays a fine section above eighty feet in thickness, and has the
advantage of full daylight as compared with Dunluce Cave. That this is
no mere neck or pipe is evident from its extent. Its position below the
basalt cap refutes the above quoted subsequent explanation, which Mr.
Hull and others have recently adopted.
The heterogeneous bomb-like character of the boulders is not so
strongly marked as in the Dunluce rock, and this may arise from the
closer proximity of the basalt, which, coming here in direct contact,
would be likely to heat the clay matrix (itself formed mainly of
ice-ground basalt) to incipient fusion, and thereby render it more like
the basalt boulders it contains than the other clay that had been less
intensely heated on account of greater distance from the lava-flow.
The path leading to the ladder by which the bridge is approached passes
over such conglomerate, and further extensions are seen in sections
around. I saw sufficient in the course of my hurried visit to indicate
the existence of a large area of this particular formation.
At a short distance from Carrick-a-Rede, on the way to Ballycastle, the
car passes in sight of considerable deposits of ordinary boulder clay
uncovered and unaltered.
The blocks of basalt, etc., embedded in this correspond in general size
and shape with the “bombs,” excepting that some of the latter have a
laminated, or shaly, character near their surfaces.
I regret my inability to do justice to this subject in consequence
of the fact that the above explanation of the origin of this curious
formation only suggested itself when hurrying homeward after a somewhat
protracted visit to Ireland. As I may not have an opportunity of
further investigation for some time to come, I offer the hypothesis in
this crude form in order that it may be discussed, and either confirmed
or refuted by the geologists of the Ordnance Survey, or others who have
better opportunities of observation than I can possibly command.
Should this conglomerate prove to be, as I suppose, a drift deposit
altered by a subsequent flow of lava, it will supply exceedingly
interesting data for the determination of the chronological relations
of the glacial epoch to that period of volcanic activity to which the
lavas of the N.E. of Ireland are due. Though it will nowise disturb
the general conclusion that the great eruptions that overspread the
cretaceous rocks of this region, and supplied the boulders of my
supposed metamorphosed drift, occurred during the Miocene period, it
will show that this volcanic epoch was of vastly greater duration than
is usually supposed; or that there must have been two or more volcanic
epochs—pre-glacial, as usually understood, and post-glacial, in order
to supply the lava overflowing the drift.
This post-glacial extension of the volcanic period has an especial
interest in Ireland, as the “Annals of the Four Masters,” and other
records of ancient Irish history and tradition, abound in accounts of
physical changes, many of which correspond remarkably with those of
recent occurrence in the neighborhood of active and extinct volcanoes.
In a paper read before the Royal Irish Academy, June 23, 1873, and
published in its “Proceedings,” Dr. Sigerson has collected some of the
best authenticated of these accounts, and compares them with similar
phenomena recently observed in Naples, Sicily, South America, Siberia,
etc. etc. The “great sobriety of diction, and circumstantial precision
of statement,” of names, dates, etc., which characterize these accounts
render them well worthy of the sort of comparison with strictly
scientific data which Dr. Sigerson has made.
As we now know that man existed in Britain during the inter-glacial, if
not the pre-glacial period, and as so violent a volcanic disturbance as
that which poured out the lavas of Antrim and the Mourne district could
scarcely have subsided suddenly, but was probably followed by ages of
declining activity, it is not at all surprising that this period of
minor activity should have extended into that of tradition and the
earliest of historical records.
TRAVERTINE.
The old exclamation about Augustus finding Rome of brick and leaving
it of marble, deceives many. Ancient Rome was by no means a marble
city, although the quarries of Massa and Carrara are not far distant.
The staple-building materials of the Imperial City, even in its
palmiest days, were brick and travertine. The brick, however, was very
different from the porous cakes of crudely burnt clay of which the
modern metropolis of the world is built. I have examined on the spot a
great many specimens, and found them all to be of remarkably compact
structure, somewhere between the material of modern terra-cotta and
that of common flower-pots, and similarly intermediate in color. The
Roman builders appear to have had no standard size; the bricks vary
even in the same building—the Coliseum for example; all that I have
seen are much thinner than our bricks—we should call them tiles.
But the most characteristic material is the travertine. The walls
of the Coliseum are made up of a mixture of this and the tiles
above-mentioned. The same is the case with most of the other very
massive ruins, as the baths, etc. Many of the temples with columns and
facing of marble have inner walls built of this mixture, while others
are entirely of travertine.
I was greatly surprised at the wondrous imperishability of this
remarkable material. In buildings of which the smooth crystalline
marble had lost all its sharpness and original surface, this dirty,
yellow, spongy-looking limestone remained without the slightest
indication of weathering. A most remarkable instance of this is
afforded by the temple of Neptune at Paestum, in Calabria. This is
the most perfect ruin of a pure classic temple that now remains in
existence, and in my opinion is the finest. I prefer it even to the
Parthenon.
We have a little sample of it in London. The Doric columns at the
entrance of the Euston station are copies of those of its peristyle.
The originals are of travertine, the blocks forming them are laid
upon each other without mortar or cement, and so truly flattened
that in walking round the building and carefully prying, I could find
no crevice into which a slip of ordinary writing paper, or the blade
of a pen-knife could be inserted. Yet this temple was an antiquarian
monument in the days of the Roman emperors.
The rough natural surface of the stone is exposed, and at first sight
appears as though weathered, but this appearance is simply due to its
natural sponge-like structure. It appears to have been coated with
some sort of stucco or smoothing film, which, either by forming a thin
layer, or possibly by only filling up the pores of the travertine, gave
a smooth surface upon which the coloring was applied. This is now only
indistinctly visible here and there, and if I remember rightly, some
have disputed its existence.
But this travertine, though so familiar to the Italian, is such
a rarity here that some further description of its structure and
composition may be demanded. It is a limestone formed by _chemical_
precipitation. Most limestones are more or less of organic origin, are
agglomerations of shells, corals, etc., but this is formed by the same
kind of action as that which produces the stalactites in limestone
caverns. It has some resemblance to the incrustation formed on boilers
by calcareous water. Although the material of so many ancient edifices,
it is, geologically speaking, the youngest of all the hard rocks. Its
formation is now in progress at some of the very quarries that supplied
Imperial Rome.
On the Campagna, between Rome and Tivoli, is a small circular lake,
from which a stream of tepid water, that wells up from below, is
continually flowing. Its local name is the “The Lake of Tartarus.”
The water, like that of Zoedone, or soda-water or champagne, is
supersaturated with carbonic acid that was forced into it while under
pressure down below. This carbonic acid has dissolved some of the
limestones through which the subterranean water passes, and when it
comes to the surface, the carbonic acid flies away like that which
escapes when we uncork a bottle of soda-water, though less suddenly,
and the lime losing its solvent is precipitated, and forms a crust on
whatever is covered by the water.
When I visited this lake in the month of February it was surrounded by
a _chevaux de frise_ of an extraordinary character; thousands of tubes
of about half an inch to one inch in diameter outside, with calcareous
walls about one eighth of an inch in thickness. These were standing up
from two to three feet high, and so close together that we had to break
our way through the dense palisade they formed in order to reach the
margin of the lake. After some consideration and inquiry, their origin
was discovered. They are the encrusted remains of bullrushes that had
flourished in the summer and died down since. During the time of their
growth the water had risen, and thus they became coated with a crust of
compact travertine. This deposition takes place so rapidly that a piece
of lace left in the lake for a few hours comes out quite stiff, every
thread being coated with limestone. Such specimens, and twigs similarly
covered, are sold to tourists or prepared by them if they have time to
stop. Sir Humphry Davy drove a stick into the bottom of the lake and
left it standing upright in the water from May to the following April,
and then had some difficulty in breaking with a sharp pointed hammer
the crust formed round the stick. This crust was several inches in
thickness. That which I saw round the ex-bullrushes may have all been
formed in a few days or weeks. The rivulet that flows from the lake
deposits travertine throughout its course, and when it overflows leaves
every blade of grass that it covers encrusted with this limestone.
Near to the Lake of Tartarus is the _Solfatara_ lake which contains
similar calcareous water, but strongly impregnated with sulphureted
hydrogen; it consequently deposits a mixture of carbonate and sulphide
of calcium, a sort of porous tufa, some of it so porous that it floats
like a stony scum, forming what the cicerone call “floating islands.”
Lyell, in his “Principles of Geology,” confounds these lakes, and
describes Tartarus under the name of Solfatara.
The travertine used as a building stone is chiefly derived from the
quarries of Ponte Lucano, and is the deposit that was formed on the bed
of a lake like that of Tartarus. The celebrated cascade of the Anio
at Tivoli forms calcareous stalactites, and all the country round has
rivulets, caverns, and deposits, where this formation may be seen in
progress or completed.
It varies considerably in structure, some specimens are compact and
smooth, others have the appearance of a petrified moss, and great
varieties may be found among the materials of a single building. It
is, however, usually rough and more or less spongy-looking, as above
stated, but this structure does not seem to affect its stability, at
least, not in the climate of Italy. Whether it would stand long frosts
is an open question. The night frosts at and about Rome are rather
severe, but usually followed by a warm sunny day; thus there is no
great penetration of ice.
Every specimen I have examined shows a remarkable compactness of
_molecular_ structure in spite of visible porosity. All give out
a clear metallic ring when struck, and the intimate surface, if I
may so describe the surface of the warm-like structure it sometimes
displays, is always clear and smooth as though varnished. To this I
attribute its durability. Lest the above description should appear
self-contradictory, I will explain a little further. If melted glass
were run into threads, and those threads while soft were allowed to
agglomerate loosely into a convoluted mass, it would, as regarded in
mass, have a porous or spongy-looking structure, but nevertheless its
_molecular_ structure would be compact and vitreous; there would be
mechanical but not molecular, porosity. Travertine is similar.
Have we any travertine in England? This is a practical question of some
importance, and one to which I have no hesitation in replying, Yes.
There is plenty formed and forming in the neighborhood of Matlock,
but that which I have seen on the face of caverns, etc., is not so
compact and metal-like as the Italian. This, however, does not prove
the entire absence of the useful travertine. Not having any commercial
interest in the search, I have only looked at what has come in my way,
but have little doubt that there are other kinds besides those I saw.
I have also seen travertine in course of formation in Ireland, where I
think there is a fine field for exploration in the mountain limestone
regions, which have been disturbed by volcanic action of the Miocene
period. The travertines of Italy are found in the neighborhood of
extinct volcanoes.
The classic associations of this material, its remarkable stability,
and the faculty with which it may be worked, render it worthy of more
attention than it has yet received from British builders.
THE ACTION OF FROST IN WATER-PIPES AND ON BUILDING MATERIALS.
Popular science has penetrated too deeply now to render necessary any
refutation of the old popular fallacy which attributed the bursting of
water-pipes to the thaw following a frost; everybody now understands
that the thaw merely renders the work of the previous freezing so
disastrously evident. Nevertheless, the general subject of the action
of freezing water upon our dwellings is not so fully understood by all
concerned as it should be. Builders and house-owners should understand
it thoroughly, as most of the domestic miseries resulting from
severe winters may be greatly mitigated, if not entirely prevented,
by scientific adaptation in the course of building construction.
Now-a-days tenants know something about this and select accordingly.
Thus the market value of a building may be increased by such adaptation.
Solids, liquids, and gases expand as they are heated. This great
general law is, however, subject to a few exceptions, the most
remarkable of which is that presented by water. Let us suppose a simple
experiment. Imagine a thermometer tube with its bulb and stem so filled
with water that when the water is heated nearly to its boiling point
it will rise to nearly the top of the long stem. Now let us cool it.
As the cooling proceeds the water will descend, and this descending
will continue until it attains the temperature marked on our ordinary
thermometer as 39°, or more strictly 39-2/10; then a strange inversion
occurs. As the temperature falls below this, the water rises gradually
in the stem until the freezing point is reached.
This expansion amounts to 1/7692 part of the whole bulk of the water,
or 100,000 parts become 100,013. So far the amount of expansion is
very small, but this is only a foretaste of what is coming. Lower the
temperature still further, the water begins to freeze, and at the
moment of freezing it expands suddenly to an extent equalling 1/15 of
its bulk, _i.e._, of the bulk of so much water as becomes solidified.
The temperature remains at 32° until the whole of the water is frozen.
Fortunately for us, the freezing of water is always a slow process,
for if this conversion of every 15 gallons into 16 took place
suddenly, all our pipes would rip open with something like explosive
violence. But such sudden freezing of any considerable quantity of
water is practically impossible, on account of the “latent heat” of
liquid water, which amounts to 142½°. All this is given out in the
act of freezing. It is this giving out of so much heat that keeps the
temperature of freezing water always at 32°, even though the air around
may be much colder. No part of the water can fall below 32° without
becoming solid, and that portion which solidifies gives out enough heat
to raise 142½ times its own quantity from 31° to 32°.
The slowness of thawing is due to the same general fact. An instructive
experiment may be made by simply filling a saucepan with snow or broken
ice, and placing it over a common fire. The slowness of the thawing
will surprise most people who have not previously tried the experiment.
It takes about as long to melt this snow as it would to raise an equal
weight of water from 32° to 174°. Or, if a pound of water at 174° be
mixed with a pound of snow at 32°, the result will be two pounds of
water at 32°; 142° will have disappeared without making the snow any
warmer, it will all have been used up in doing the work of melting.
The force with which the great expansion due to freezing takes place is
practically irresistible. Strong pieces of ordnance have been filled
with water, and plugged at muzzle and touch-hole. They have burst in
spite of their great thickness and tenacity. Such being the case, it
is at first sight a matter of surprise that frozen water-pipes, whether
of lead or iron, ever stand at all. They would not stand but for
another property of ice, which is but very little understood, viz., its
_viscosity_.
This requires some explanation. Though ice is what we call a solid,
it is not truly solid. Like other apparent solids it is not perfect
rigid, but still retains some degree of the possibility of flowing
which is the characteristic of liquids. This has been shown by filling
a bombshell with water, leaving the fuse-hole open and freezing it. A
shell of ice is first formed on the outside, which of course plugs up
the fuse-hole. Then the interior gradually freezes, but the expansion
due to this forces the ice out of the fuse-hole as a cylindrical stick,
just as putty might be squeezed out, only that the force required to
mould and eject the ice is much greater.
I have constructed an apparatus which illustrates this very strikingly.
It is an iron syringe with cylindrical interior of about half an inch
in diameter, and a terminal orifice of less than 1/20 of an inch in
diameter. Its piston of metal is driven down by a screw. Into this
syringe I place small fragments of ice, or a cylinder of ice fitted to
the syringe, and then screw down the piston. Presently a thin wire of
ice is squirted forth like vermicelli when the dough from which it is
made is similarly treated, showing that the ice is plastic like the
dough, provided it is squeezed with sufficient force.
This viscosity of ice is displayed on a grand scale in glaciers, the
ice of which actually flows like a river down the glacier valley,
contracting as the valley narrows and spreading out as it widens, just
as a river would; but moving only a few inches daily according to the
steepness of the slope and the season, slower in winter than in summer.
Upon this, and the slowness of the act of freezing, depends the
possibility of water in freezing in iron pipes without bursting them.
Even iron yields a little before bursting, but ordinary qualities not
sufficiently to bear the expansion of 1/15 of their contents. What
happens then? The cylinder of ice contained in the tube elongates as
it freezes, provided always the pipe is open at one or both ends.
But there is a limit to this, seeing that the friction of such a
tight-fitting core, even of slippery ice, is considerable, and if
the pipe be too long, the resistance of this friction may exceed the
resistance of tenacity of the pipe. I am unable to give any figures for
such length; the subject does not appear to have been investigated as
it should be, and as it might well be by our wealthy water companies.
We all know that lead pipes frequently succumb, but a little
observation shows that they do so only after a struggle. The tenacity
of lead is much less than that of iron (about 1/20 of that of ordinary
wrought iron), but it yields considerably before breaking. It has, in
fact, the property of viscosity similar to that of ice. At Woolwich the
lead used for elongated rifle bullets is squirted like the ice in my
syringe above described, powerful hydraulic pressure being used.
This yielding saves many pipes. It would save all _new_ pipes if the
lead were pure and uniform; but as this is not the case, they may burst
at a weak place, the yielding being shown by the bulge that commonly
appears at the broken part.
From the above it will be easily understood that a pipe which is
perfectly cylindrical—other conditions equal—will be less likely to
burst than one which is of varying diameter, as the sliding from a
larger to a smaller portion of the pipe must be attended with great
resistance, or a certain degree of block, beyond what would be due to
the mere friction along a pipe of uniform diameter.
Let us now consider the relative merits of lead and iron as material
for water-pipes in places where exposure to frost is inevitable. Lead
yields more than iron, and so far has an advantage; this, however is
but limited. As lead is practically inelastic, every stretch remains,
and every stretch diminishes the capacity for further stretching; the
lead thus stretched at one frost is less able to stretch again, and has
lost some of its original tenacity. Hence the superiority of new leaden
pipes. Iron is elastic within certain limits, and thus the iron pipe
may yield a little without permanent strain or “distress,” and if its
power of elastic resistance is not exceeded, it regains its original
size without becoming sensibly weaker. Add to this its great tenacity,
its nonliability to be indented, or otherwise to vary in diameter, and
we have a far superior material.
But this conclusion demands some qualification. There is iron and
iron, cast-iron and wrought-iron, and very variable qualities of each
of these. I need scarcely add that common brittle cast-iron is quite
out of the question for such purposes, though there is a new kind of
cast-iron or semi-steel coming forward that may possibly supersede all
other kinds; but this opens too wide a subject for discussion in the
present paper, the main object of which has been a popular exposition
of the general physical laws which must be obeyed by the builder, or
engineer, who desires to construct domestic or other buildings that
will satisfy the wants of intelligent people.
The mischievous action of freezing water is not confined to the pipes
that are constructed to receive or convey it. Wherever water may be,
if that water freezes, it must expand in the degree and with the force
already described. If it penetrates stone or brick, or mortar or
stucco, and freezes therein, one of two things must occur—either the
superfluous ice must exude at the surface or to neighboring cavities,
or the saturated material must give way, and split or crumble according
to the manner and degree of penetration. To understand this, the reader
must remember what I stated about the little-understood _viscosity_ of
ice, as well as its expansion at the moment of freezing.
Bricks are punished, but not so severely as might be anticipated,
seeing how porous are some of the common qualities, especially those
used in London. They are so amply porous that the water not only finds
its way into them, but the pores are big enough and many enough for
the ice to demonstrate its viscosity by squeezing out and displaying
its crystalline structure in the form of snow-like efflorescence on
the surface. This may have been observed by some of my readers during
a severe frost. It is commonly confounded with the hoar-frost that
whitens the roofs of houses, but which is very rarely deposited on
perpendicular wall faces.
The mortar most liable to suffer is that which is porous and
pulverulent within, but has been cleverly faced or pointed with a
crust of more compact material. This outer film prevents the exuding
of the expanding ice crystals, is thrust forth bodily, and retained by
ice-cement during the frost, but it falls in scales when this temporary
binding material thaws. Mortar that is compact throughout does not
suffer to any appreciable extent. This is proved by the condition of
the remains of Roman brickwork that still exist in Britain and other
parts of Europe. Some of the old shingle walls at Brighton and other
parts of the south coast, where the chalk for lime-burning was at the
builder’s feet, and where his mortar is so thickly laid between the
irregular masses of flint, also show the possible duration of good
mortar. The jerry builder’s mortar, made of the riddlings of burnt
clay ballast and dust-hole refuse just flavored with lime, crumbles
immediately, because these materials do not combine with the lime as
fine siliceous sand gradually does, to form an impermeable glassy
silicate.
Stucco is punished by two distinct modes of action. The first is where
the surface is porous, and the water permeates accordingly and freezes.
This, of course, produces superficial crumbling, which should not occur
at all upon good material protected by suitable paint. The other case,
very deplorable in many instances, is where the water finds a space
between the inner surface of the stucco and the outer surface of the
material upon which it is laid. This water, when frozen, of course,
expands, and wedges away the stucco bodily, causing it to come down in
masses at the thaw. This, however, only occurs after severe frosts,
as the ordinary mild frosts of our favored climate seldom endure long
enough to penetrate to any notable depth of so bad a conductor as stone
or stucco. It is worthy of note that water is a still worse conductor
than stone.
Building stones are so various both in chemical composition and
mechanical structure that the action of freezing water is necessarily
as varied as the nature of the material. The highly siliceous granites
(or, rather, porphyries that commonly bear the name of granite) are
practically impermeable to water so long as they are free from any
chemical decomposition of their feldspathic constituents; but when we
come to sandstones and limestones, or intermediate material, very wide
differences prevail.
The possible width of this difference is shown in the behavior of the
unselected material in its natural home. Certain cliffs and mountains
have stood for countless ages almost unchanged by the action of
frost; others are breaking up with astonishing rapidity in spite of
apparent solidity of structure. The Matterhorn, or Mont Cervin, one
of the most gigantic of the giant Alps, 15,200 feet high, is rendered
especially dangerous to ambitious climbers by the continual crashing
down of fragments that are loosened when the summer sun melts the ice
that first separated and then for a while held them in their original
places. All the glaciers of the Alps are more or less streaked with
“moraines,” which are fragments of the mountains that freezing water
has detached.
Our stone buildings would suffer proportionally if some selection of
material were not made. Generally speaking, this selection is based
upon the experience of previous practical trials. Certain quarries are
known to have supplied good material of a certain character, and this
quarry has, therefore, a reputation which is usually of no small value
to its fortunate owner. Other quarries are opened in the neighborhood
wherever the rock resembles that of the tested quarry.
Sometimes, however, materials are open for selection that have not been
so well tested, and a method of testing which is more expeditious and
less expensive than constructing a building and watching the result, is
very desirable. The subject of testing building materials in special
reference to their resistance of frost was brought before the Academy
of Science of Paris by M. Brard some years since.
In his preliminary experiments he used small cubes of the stone to
be tested, soaked them in water, and then exposed them to the air in
frosty weather, or subjected them to the action of freezing mixtures.
Afterwards he found that by availing himself of the expansive force
which certain saline solutions exert at the moment of crystallization,
he could conveniently imitate the action of freezing without the aid
of natural or artificial frost. Epsom salts, nitre, alum, sulphate of
iron, Glauber’s salts, etc., were tried. The last named, Glauber’s salt
(or sulphate of soda), which is very cheap, was found to be the best
for the purpose.
His method of applying the test is as follows: Cut the specimens into
two-inch cubes, with flat sides and sharp edges and corners, mark each
specimen with a number, either by ink or scratching, and enter in a
book all particulars concerning it. Make a saturated solution of the
sulphate of soda in rain or distilled water, by adding the salt until
no more will dissolve; perfect saturation being shown by finding, after
repeated stirring, that a little of the salt remains at the bottom
an hour or two after the solution was made. Heat this solution in a
suitable vessel, and when it boils put in the marked specimens one by
one, and keep them immersed in the boiling solution for half an hour.
Take out the specimens separately and suspend them by threads, each
over a separate vessel containing some of the liquid in which they were
boiled, but which has been carefully strained to free it from any solid
particles. In the course of a day or two, as the cubes dry, they will
become covered with an efflorescence of snow-like crystals; wash these
away by simply plunging the specimen into the vessel below, and repeat
this two or three times daily for four or five days or longer. The most
suitable vessel for the purpose is a glass “beaker,” sold by vendors of
chemical apparatus.
In comparing competing samples, be careful to treat all alike, _i.e._,
boil them together in the same solution, and dip them an equal number
of times at equal intervals.
Having done this, the result is now to be examined. If the stone is
completely resistant the cube will remain smooth on its surfaces and
sharp at its edges and corners, and there will be no particles at the
bottom of the vessel. Otherwise, the inability of the stone to resist
the test will be shown by the disfigurement of the cube or the small
particles wedged off and lying at the bottom of the liquid. Care must
be taken not to confound these with crystals of the salt which may also
be deposited. These crystals are easily removed by adding a little more
water or warming the solution.
For strict comparison the fragments thus separated should be weighed in
a delicate balance, such as is used in chemical analysis.
THE CORROSION OF BUILDING STONES.
About fifty years ago two eminent French chemists visited London, and
rather “astonished the natives” by a curious feature of their dress.
They wore on their hats large patches of colored paper. Coming, as they
did, from Paris, many supposed that this was one of the latest Paris
fashions, and the dandies of the period narrowly escaped the compulsion
to follow it. They probably would have done so had the Frenchmen shown
any attempt at decorative shaping of the paper. They neglected this
because it was litmus paper, and their object in attaching it to their
hats was to test the impurities of the London atmosphere.
Blue litmus paper, as everybody knows now-a-days, turns red
when exposed to an acid. The French chemists found that their
hat-decorations changed color, and indicated the presence of acid in
the air of London; but when they left the metropolis and wandered in
the open fields their blue litmus paper retained its original color. By
using alkaline paper they contrived to collect enough of the acid to
test its composition. They found it to be the acid which is formed by
the burning of sulphur, and attributed its existence to the sulphur of
our coal. At this time the domestic use of coal was scarcely known in
Paris.
Subsequent experiments have proved that they were right; that the
air of London contains a very practical quantity of sulphurous and
sulphuric acids, which are due to the combustion of that yellow shining
material more or less visible in most kinds of coal, and has been
occasionally supposed to be gold. It is iron pyrites, a compound of
iron and sulphur. When heated the sulphur is separated and burns,
producing sulphurous acid, which, exposed to moist air, gradually
takes up more oxygen and becomes sulphuric acid, which in concentrated
solution is oil of vitriol. In the air it is very much diluted by
diffusion, but is still strong enough to do mischief to some kinds of
building materials.
In manufacturing towns, such as Birmingham and Sheffield, the quantity
of this acid in the air is much greater than in London, and there
its mischief is consequently more distinctly visible. The church of
St. Philip, which stands nearly in the middle of Birmingham, and is
surrounded by an old churchyard, was so corroded by this acid that the
stone peeled away on all sides, and its condition was most deplorable.
The tombstones were similarly disintegrated on their surfaces, and
inscriptions quite obliterated. It became so bad that a few years ago
restoration was necessary, and it was newly faced accordingly.
Some of the old tombstones that are preserved may still be seen against
the church wall, and their peculiar structure is well worthy of study.
They display a lamination or peeling away due to unequal corrosion,
certain layers of the material of the stone having been evidently eaten
away more rapidly than others. Anybody visiting Birmingham may easily
examine these, as St. Philip’s churchyard is situated between the two
railway stations of New Street and Snow Hill, and is but two minutes’
walk from either.
Other stone buildings in the town have suffered, but in very different
degrees, and some have quite escaped, proving the necessity of careful
selection of material wherever coal fires abound. In Birmingham the
action of coal fires is assisted by other sources of acid vapor.
The process of “pickling” brass castings, _i.e._, brightening their
surface, by dipping first in common nitric acid (“pickle acky”) and
then in water, is attended with considerable evolution of acid fumes.
Besides this very widespread use of acid, there are several chemical
manufactories that throw still more acid into the air immediately
surrounding them.
As an example of the action of the atmospheric acids of London upon
building stones, I have but to name the Houses of Parliament, which
have only been rescued from superficial ruin by the patchwork replacing
of certain blocks of stone, and various devices of siliceous and other
washings that have been carried out at great cost to the nation. That
such an unsuitable material should have been used is disgraceful to
all concerned. The ruin commenced before the building was finished. At
the time when its erection commenced there were abundant evidences of
the ruinous action of London atmosphere on some kinds of stone and the
capability of others to resist it, for while many modern buildings are
peeling and crumbling, some of the oldest in the midst of the city show
scarcely any signs of corrosion.
The Birmingham and Midland Institute was established and in practical
operation a few years before the present noble building was erected. I
was the first teacher there and conducted the Science classes in the
temporary premises in Cannon street. Having observed with some interest
the disintegration of St. Philip’s Church and other buildings, I was
anxious for the safety of the new Institute buildings, and accordingly
made some experiments upon the material proposed to be used by the
architect. My method of testing was very simple, and as the practical
result has verified my anticipations I think it might be adopted by
others.
First, I immersed some lumps of the stone in moderately strong
solutions of sulphuric and hydrochloric acids successively, and
observed whether any visible action occurred after some days. There
was none. I then roughly tested the crushing pressure of small samples
in their natural state, and subjected similar sized pieces to the same
test after they had been immersed in the acids. I found thus that there
were no evidences of internal disintegration even after several days’
immersion, and therefore inferred that the stone would stand the acid
vapors of the Birmingham atmosphere. This has been the case with that
portion of the building that was built of the material I tested. As
I know nothing of the stone which is used for the extension of the
building under the present architect, Mr. Chamberlain, I am unable to
make any forecast of its probable durability.
The experiments I made at the time named with this and other building
materials justified the conclusion that the worst of all material for
exposure to acid atmospheres is a sandstone, the particles of which
are held together by limestone, or are otherwise surrounded by or
intermingled with limestone; and that the best of _ordinary_ material
is a pure sandstone quite free from lime. I do not here consider such
luxurious material as granite or porphyries.
Compact limestone, such as good homogeneous marble, stands fairly
well, although it is slowly corroded. The corrosion, however, in this
case, is purely superficial and tolerably uniform. It is a very slow
washing away of the surface, without any disintegration such as occurs
where a small quantity of limestone acts as binding material to hold
together a large quantity of siliceous or sandy material, and where
the agglomeration is porous, and the stone is so laid that a downward
infiltration of water can take place; for it must be remembered that
although the acid originally exists as vapor in the air, it is taken up
by the falling rain, and the mischief is directly done to the stone by
the acidified water. This, of course, is very weak acid indeed. That
which I used for testing the stone was many thousand times stronger,
but then I exposed the stone for only a few days instead of many
thousand days.
As above stated, my experiments were but rude, but I think it
would be quite worth while to construct crushing apparatus capable
of registering accurately the pressure used, and to operate with
standard solutions of acid upon carefully squared blocks of standard
size, and thus to make comparative tests of various samples of stone
when competitions for building materials are offered. In the case
of the Birmingham and Midland Institute building there was no such
competition, the choice was left entirely to the architect, and my
examination was unofficially conducted upon the material already chosen
with the intent of protesting if it failed. As it stood the test I
merely reported the results informally to the architect, the late Sir
Edward Barry, no further action being demanded.
FIRE-CLAY AND ANTHRACITE.
For household fire-places, whether open or closed, these may be
regarded as the material and the fuel of the future, and should be more
generally and better understood than they are.
The merits of fire-clay were fully appreciated and described nearly a
hundred years ago by that very remarkable man, Benjamin Thompson, Count
of Rumford. Any sound scientific exposition of the relative value of
fire-clay and iron as fire-place materials can be little more or less
than a repetition of what he struggled to teach at the beginning of the
present century.
It is impossible to fairly understand this subject unless we start with
a firm grasp of first principles. The business before us is to get as
much heat as possible from fuel burning in a certain fashion, and to do
this with the smallest possible emission of smoke.
Substances that are hotter than their surroundings communicate their
excess of temperature in three different ways; 1st, by _Conduction_;
2d, by _Convection_; 3d, by _Radiation_. All of these are operating in
every form of fire-place, but in very different proportions according
to certain variations of construction.
To demonstrate the conduction of heat, hold one end of a pin between
the finger and thumb, and the other end in the flame of a candle. The
experiment will terminate very speedily. Then take a piece of a lucifer
match of the same length as the pin, and hold that in the candle. This
may become red-hot and flaming without burning the fingers, as the pin
did at a much lower temperature. It matters not whether the pin be held
upwards, downwards, or sideways, the heat will travel throughout its
substance, and this sort of traveling is called “conduction,” and the
pin a “conductor” of heat. The conducting power of different substances
varies greatly, as the above experiment shows. Metals generally are
the best conductors, but they differ among themselves; silver is the
best of all, copper the next. Calling (for comparison sake) the
conductivity of silver 1000, that of copper is 736, gold 532, brass
236, iron 119, marble and other building stones 6 to 12, porcelain 5,
ordinary brick earth only 4, and fire-brick earth less than this. Thus
we may at once start upon our subject, with the practical fact that
iron conducts heat thirty times more readily than does fire-brick.
_Convection_ is different from conduction, inasmuch as it is effected
by the movements of the something which has been heated by contact
with something else. Water is a very bad conductor of heat, much worse
than fire-brick, and yet, as we all know, heat is freely transmitted
by it, as when we boil water in a kettle. If, however, we placed the
water in a fire-clay kettle, and applied the heat at the top we should
have to wait for our tea until to-morrow or the next day. When the
heat is applied below, the hot metal of the kettle heats the bottom
film of water by _direct contact_; this film expands, and thus, being
lighter, rises through the rest of the water, heating other portions
by contact as it meets them, and so on throughout. The heat is thus
conveyed, and the term “convection” is based on the view that each
particle is a carrier of heat as it proceeds. Air conveys heat in the
same manner; so may all gases and liquids, but no such convection is
possible in solids. The common notion that “heat ascends” is based on
the well-known facts of convection. It is the heated gas or liquid that
really ascends. No such preference is given to an upward direction,
when heat is conducted or radiated.
_Radiation_ is a flinging off of heat in all directions by the heated
body. Radiation from solids is mainly superficial, and it depends on
the nature of the heated surface. The rougher and the more porous the
surface of a given substance the better it radiates. Bright metals are
the worst radiators; lampblack the best, and fire-brick nearly equal to
it. To show the effect of surface, take three tin canisters of equal
size, one bright outside, the second scratched and roughened, the third
painted over with a thin coat of lampblack. Fill each with hot water of
the same temperature, and leave them equally exposed. Their rates of
radiation will then be measurable by their rates of cooling. The black
will cool the most rapidly, the rough canister next, and the bright one
the slowest.
Radiant heat may be reflected like light from bright surfaces, the
reflecting substance itself becoming heated in a proportion which
diminishes just as its reflecting powers increase. Good reflectors are
bad radiators and bad absorbers of heat, and the power of _absorbing_
heat, or becoming superficially hot when exposed to radiant heat, is
exactly proportionate to radiating efficiency.
Fire-clay is a good absorber of radiant heat, _i.e._, it becomes
readily heated when near to hot coals or flames, without requiring
actual contact with them. It is an equally good radiator.
Let us now apply these facts to fire-clay in fireplaces, beginning
with ordinary open grates used for the warming of apartments; first
supposing that we have an ordinary old-fashioned grate all made of
iron—front, sides, and back, as well as bars, and next that we have
another of similar form and position, but all the fire-box and the back
and cheeks of the grate made of fire-clay.
It is evident that the fire-clay not in actual contact with the
coals, but near to them, will absorb more heat than the iron, and
thus become hotter. Even at the same temperature it will radiate much
more heat than iron, but being so much hotter this advantage will be
proportionately increased. An open fireplace lined throughout with
fire-clay thus throws into the room a considerable amount of its own
radiation in addition to that thrown out from the coal.
But what becomes of this portion of the heat when the fireplace is all
of metal? It is carried up the chimney by convection, for the metal,
while it parts with less heat by radiation, gives up more to the air
by direct contact. Therefore, if we must burn our coals inside the
chimney, we lose less by burning them in a fire-clay box than in a
metal box.
Count Rumford demonstrates this, and described the best form of open
firegrate that can be placed in an ordinary English hole-in-the-wall
fireplace. The first thing to be done, according to his instructions,
is to brick up your large square fireplace recess, so that the back of
it shall come forward to about 4 inches from the front inside face of
the chimney, thus contracting the _throat_ of the chimney, just behind
the mantel, to this small depth (Rumford’s device for sweeping need not
be here described). The sides or “covings” of this shallowed recess
are now to be sloped inwards so that each one shall horizontally be at
an angle of 135 deg. to the plane of this new back, and meet it at a
distance of six or more inches apart, according to the size of grate
required. The covings will thus spread out at right angles with each
other, and leave an annular opening to be lined with fire-brick, and
run straight up to the chimney. The fire-bars and grate-bottom to be
simply let into this as far forward as possible.
By this simple arrangement we get a fire-grate with a narrow flat back
and out-sloping sides; all these three walls are of fire-brick; the
back radiates perpendicularly across the room; and the sloping sides
radiate outwards, instead of merely across the fire from one to the
other, as when they are square to the walls.
At Rumford’s time our ordinary fireplaces were square recesses; now
we have adopted something like his suggestion in the sloping sides
of our register grates, and we bring our fireplaces forward. We have
gone backwards in material, by using iron, but this, after all, may
be merely due to the ironmongery interest overpowering that of the
bricklayers. The preponderance of this interest in the South Kensington
Exhibition may account for the fact that Rumford’s simple device was
not to be seen in action there. It could not pay anybody to exhibit
such a thing, as nobody can patent it, and nobody can sell it. I have
seen the Rumford arrangement carried out in office fireplaces with
remarkable success. To apply it anywhere requires only an intelligent
bricklayer, a few bricks, and some iron bars.
Although nobody exhibited this, a very near approach to it was
described in an admirable lecture delivered at South Kensington, by
Mr. Fletcher, of Warrington. In one respect Mr. Fletcher goes further
than Count Rumford in the application of fire-clay. He makes the
bottom of the fire-box of a slab of fire-clay instead of ordinary iron
fire-bars. This demands a little more trouble and care in lighting
the fire, owing to the absence of bottom-draught, but when the fire is
well started the advantages of this further encasing in fire-clay are
considerable. They depend upon another effect of the superior radiant
and absorbent properties of fire-clay that I will now explain.
So far, I have only described the beneficial effect of its radiation
on the room to be heated, but it performs a further duty inside the
fireplace itself. Being a bad conductor, it does not readily carry
away the heat of the burning coal that rests upon it, and being also
an excellent absorber, it soon becomes very hot—_i.e._, superficially
hot, or hot where its heat is effective. This action may be seen in
a common register stove with fire-clay back and iron sides. When
the fire is brisk the back is visibly red-hot, while the sides are
still dull. If, after such a fire has burnt itself out, we carefully
examine the ashes, there will be found more fine dust in contact with
the fire-brick than with the iron—_i.e._, evidence of more complete
combustion there; and one of the advantages justly claimed by Mr.
Fletcher is, that with his solid fire-clay bottom there will be no
unburnt cinders—nothing left but the incombustible mineral ash of the
coal. Economy and abatement of smoke are the necessary concomitants of
such complete combustion.
A valuable “wrinkle” was communicated by Mr. Fletcher. The powdered
fire-clay that is ordinarily sold is not easily applied on account of
its tendency to crumble and peel off the back and sides of the stove
after the first heating. In order to overcome this, and obtain a fine
compact lining, Mr. Fletcher recommends the mixing of the fireclay
powder with a solution of water-glass (silicate of soda) instead of
simple water. It acts by forming a small quantity of glassy silicate of
alumina, which binds the whole of the clay together by its fusion when
heated.
Londoners, and, in fact, Englishmen generally, have hitherto regarded
anthracite as a museum mineral and a curiosity, rather than an everyday
coal-scuttle commodity. If it is to be the fuel of the future, it is
very desirable that we should all know something about its merits and
demerits, as well as the possibilities of supply.
Anthracite is a natural coke. From its position in the earth, and its
relations to bituminous coal, as well as from its composition, we are
justified in regarding it as a coal that was originally bituminous,
but which has been altered by heat, acting under great pressure. In
the great coal-field of South Wales, to which we must look for our
main supply of anthracite, we are able to trace the action of heat
in producing a whole series of different classes of coal in a single
seam, which at one part is highly bituminous—soft, flaming coal,
like the Wallsend, then it becomes harder and less bituminous, then
semi-bituminous “steam coal,” then less and less flaming, until at
last we have the hard, shiny form of purely carbonaceous coal, that
may be handled without soiling the fingers, and which burns without
flame, like coke or charcoal. This change proceeds as the seam extends
from the east towards the west. In some places the coal at the base of
a hill may be anthracite, while that on the outcrop above it may be
bituminous.
An artificial anthracite may be made by heating coal in a closed vessel
of sufficient strength to resist the expansion of the gases that are
formed. It differs from coke in being compact, is not porous, and
therefore, of course, much denser, a given weight occupying less space.
That we Englishmen should be about the last of all the coal-using
peoples to apply anthracite to domestic purposes is a very curious
fact, but so it is. In America it is the ordinary fuel, and this is
the case in all other countries where it is obtainable at the price
of bituminous coal. Our perversity in this respect shows out the more
strikingly when we go a little further into the subject by comparing
the two classes of coal in reference to our methods of using them,
and when we consider the fact that our South Wales anthracite is far
superior to the American.
Our open fires only do their small fraction of useful work by
radiation. Their convection is all up the chimney. Such being the case,
and we being theoretically regarded as rational beings, it might be
supposed that for our national and especially radiating fireplaces we
should have selected a coal of especial radiating efficiency, but,
instead of this, we do the opposite. The flaming coal is just that
which flings the most heat up the chimney, and the least into the
room, and, as though we were all struggling to destroy as speedily as
possible the supposed physical basis of our prosperity, we select that
coal which in our particular fire-places burns the most wastefully. If
we had closed iron stoves with long stove-pipes in the room, giving
to the air the heat they had obtained by the convective action of the
flame and smoke, there might be some reason for using the flaming coal,
as the flame would thereby do useful work, but, as it is, we stubbornly
persist in using only the radiated heat, and at the same time select
just the coal which supplies the smallest quantity of what we require.
No scientific dissertation is necessary to prove the superior radiating
power of an anthracite fire to anybody who has ever stood in the front
of one. This is most strikingly demonstrated by those grates that stand
well forward, and are kept automatically filled with the radiant-carbon.
Let us now see _why_ anthracite is a better radiator than bituminous
coal. This is due to its chemical composition. Of all the substances
that we have upon the earth carbon in its ordinary black form is the
best radiator. Anthracite contains from 90 to 94 per cent of pure
carbon, bituminous coal from 70 to 85, and much of this being combined
with hydrogen burns away as flame. On a rough average we may say that
the fixed or solid carbon capable of burning with a smokeless flameless
glow, amounts to 65 per cent in ordinary British bituminous coal,
against an average of 92 per cent in British anthracite. The advantages
of anthracite as a fuel for open radiating grates are nearly in the
proportion of these figures. Besides this it contains about half the
quantity of ash. Thus we see that from a purely selfish point of view,
and quite irrespective of our duty to our fellow-citizens as regards
polluting the atmosphere, anthracite is preferable to ordinary coal on
economical grounds, supposing we can obtain it at the same price as
bituminous coal, which is now the case.
Another great advantage of anthracite is its cleanliness, It may be
picked up in the fingers without soiling them, and it is similarly
cleanly throughout the house. It produces no “blacks,” no grimy dust,
and if it were generally in use throughout London one half of the
house-cleaning would be saved. White curtains, blinds, etc., might hang
quite four times as long, and then come down not half so dirty as now.
The saving in soap alone, without counting labor, would at once return
a handsome percentage on the capital outlay required for reconstructing
all our fireplaces.
Let us now look on the other side, and ask what are the disadvantages
of anthracite, and why is it not at once adopted by everybody? There is
really only one disadvantage, viz., the greater difficulty of starting
an anthracite fire. Practically this is considerable, seeing that
laziness is universal and ever ready to find excuses when an innovation
is proposed that stands in its way. To light an anthracite fire in an
ordinary fireplace the bellows are required unless a specially suitable
draught or fire-lighter is used. Some recommend that an admixture of
bituminous coal should be used to start it, but this is a feeble device
calculated to lead to total failure, seeing that the sole originator
and sustainer of our ordinary use of bituminous coal is domestic
ignorance and indolence, and if both kinds of coal are kept in a house
a common English servant will stubbornly use the easy-lighting kind,
and solemnly assert that the other cannot be used at all. The only way
to deal with this obstacle, the human impediment, is to say, “This you
must use, or go.” This is strictly just, as a simple enforcement of
duty.
At the same time some help should be supplied in the way of artificial
modes of creating a draught in starting an anthracite fire. This may
be done by temporarily closing the front of the fire by a “blower,”
or better still by selecting one of the grates specially devised for
burning anthracite, of which so many now are made. Another and rather
important matter is to obtain the anthracite in suitable condition. It
is a very hard coal, too hard to be broken by the means usually at hand
in ordinary houses. For domestic purposes it should always be delivered
broken up of suitable size, from that of an egg to a cocoa-nut. For
furnaces, of course, large lumps are preferable.
Then, again, anthracite must not be stirred and poked about; once
fairly started it burns steadily and brightly, demanding only a steady
feeding. The best of the special grates are more or less automatic
in the matter of feeding, and thus the trouble of lighting is fully
compensated by the absence of any further trouble.
As regards the supply. This for London and the greater part of England
will doubtless be derived from the great coal-field of South Wales.
The total quantity of available coal in this region after deducting
the waste in getting, was estimated by the Government Commissioners
at 32,456 millions of tons. It is very difficult or impossible to
correctly estimate the proportion of anthracite in this, but supposing
it to be one tenth of true anthracite it gives us 3245 millions of
tons, or about enough for the domestic supply of the whole country
during 100 years, assuming that it shall be used less wastefully than
we are now using bituminous coal, which would certainly be the case.
But, including the imperfect anthracite, the quantity must be far
larger than this, and we have to add the other sources of anthracite.
We need not, therefore, have any present fear of insufficient supply;
probably before the 100 years are ended we shall find other sources
of anthracite, or even have become sufficiently civilized to abolish
altogether our present dirty devices, and to adopt rational methods of
warming and ventilating our houses. When we do this any sort of coal
may be used.
COUNT RUMFORD’S COOKING-STOVES.
In the preceding chapter I described Count Rumford’s modification
of the English open firegrate which eighty years ago was offered to
the British nation without any patent or other restrictions. Its
non-adoption I believe to be mainly due to this—it was nobody’s
monopoly, nobody’s business to advertise it, and, therefore, nobody
took any further notice of it; especially as it cannot be made and
sold as a separate portable article.
An ironmonger or stove-maker who should go to the expense of exhibiting
Rumford’s simple structure of fire-bricks and a few bars, described
in the last chapter, would be superseding himself by teaching his
customers how they may advantageously do without him.
The same remarks apply to his stoves for cooking purposes. They
are not iron boxes like our modern kitcheners, but are brick
structures, matters of masonry in all but certain adjuncts, such as
bars, fire-doors, covers, oven-boxes, etc., which are very simple
and inexpensive. Even some of Rumford’s kitchen utensils, such as
the steamers, were cheaply covered with wood, because it is a bad
conductor, and therefore wastes less heat than an iron saucepan lid.
Rumford was no mere theorist, although he contributed largely to pure
science. His greatest scientific discoveries were made in the course
of his persevering efforts to solve practical problems. I must not be
tempted from my immediate subject by citing any examples of these, but
may tell a fragment of the story of his work so far as it bears upon
the subject of cooking-ranges.
He began life as a poor schoolmaster in New Hampshire, when it was a
British colony. He next became a soldier; then a diplomatist; then in
strange adventurous fashion he traveled on the Continent of Europe,
entered the Bavarian service and began his searching reform of the
Bavarian army by improving the feeding and the clothing of the men. He
became a practical working cook in order that they should be supplied
with good, nutritious, and cheap food.
But this was not all. He found Munich in a most deplorable condition
as regards mendicity; and took in hand the gigantic task of feeding,
clothing, and employing the overwhelming horde of paupers, doing this
so effectually that he made his “House of Industry” a true workhouse;
it paid all its own expenses, and at the end of six years left a net
profit of 100,000 florins.
I mention these facts in conformation of what I said above concerning
his practical character. Economical cookery was at the root of his
success in this maintenance of a workhouse without any poor-rates.
After doing all this he came to England, visited many of our public
institutions, reconstructed their fireplaces, and then cooked dinners
in presence of distinguished witnesses, in order to show how little
need be expended on fuel, when it is properly used.
At the Foundling Institution in London he roasted 112 lbs. of beef with
22 lbs. of coal, or at a cost of less than threepence. The following
copy of certificate, signed by the Councillor of War, etc., shows what
he did at Munich: “We whose names are underwritten certify that we have
been present frequently when experiments have been made to determine
the expense of fuel in cooking for the poor in the public kitchen of
the military workhouse at Munich, and that when the ordinary dinner has
been prepared for 1000 persons, the expense for fuel has not amounted
to quite 12 kreutzers.” Twelve kreutzers is about 4½_d._ of our money.
Thus only 1-50th of a farthing was expended on cooking each person’s
dinner, although the peas which formed the substantial part of the soup
required five hours, boiling. The whole average daily fuel expenses of
the kitchen of the establishment amounted to 1-20th of a farthing for
each person, using wood, which is much dearer than coal. At this rate,
_one ton of wood should do the cooking for ten persons during two years
and six days, or one ton of coal would supply the kitchen of such a
family three and a half years_.
The following is an abstract of the general principles which he
expounds for the guidance of all concerned in the construction of
cooking stoves.
1. All cooking fires should be enclosed.
2. Air only to be admitted from below and under complete control. All
air beyond what is required for the supply of oxygen “is a thief.”
3. All fireplaces to be surrounded by non-conductors, _brickwork, not
iron_.
4. The residual heat from the fireplace to be utilized by long journeys
in returning flues, and by _doing the hottest work first_.
5. Different fires should be used for different work.
The first of these requirements encounters one of our dogged insular
prejudices. The slaves to these firmly believe that meat can only be
roasted by hanging it up to dry in front of an open fire; their savage
ancestors having held their meat on a skewer or spit over or before an
open fire, modern science must not dare to demonstrate the wasteful
folly of the holy sacrifice. Their grandmothers having sent joints to
a bakehouse, where other people did the same, and having found that
by thus cooking beef, mutton, pork, geese, etc., some fresh, and some
stale, in the same oven, the flavors became somewhat mixed, and all
influenced by sage and onions, these people persist in believing that
meat cannot be roasted in any kind of closed chamber.
Rumford proved the contrary, and everybody who has fairly tried the
experiment knows that a properly ventilated and properly heated
roasting oven produces an incomparably better result than the old
desiccating process.
Rumford’s roaster was a very remarkable contrivance, that seems to have
been forgotten. It probably demands more intelligence in using it than
is obtainable in a present-day kitchen. When the School Boards have
supplied a better generation of domestic servants we may be able to
restore its use.
It is a cylindrical oven with a double door to prevent loss of heat. In
this the meat rests on a grating over a specially constructed gravy and
water dish. Under the oven are two “blow-pipes,” _i.e._, stout tubes
standing just above the fire so as to be made red hot, and opening into
the oven at the back, and above the fireplace in front, where there is
a plug to be closed or open as required. Over the front part of the top
of the oven is another pipe for carrying away the vapor. It is thus
used: The meat is first cooked in an atmosphere of steam formed by the
boiling of water placed in the bottom of the double dish, over which
the meat rests. When by this means the meat has been raised throughout
its whole thickness to the temperature at which its albumen coagulates,
the plugs are removed from the blow-pipes, and _then_ the special
action of roasting commences by the action of a current of superheated
air which enters below and at the back of the oven, travels along and
finds exit above and in front of the steam-pipe before named.
The result is a practical attainment of theoretical perfection. Instead
of the joint being dried and corticated outside, made tough, leathery,
and flavorless to about an inch of depth, then fairly cooked an inch
further, and finally left raw, disgusting, and bloody in the middle, as
it is in the orthodox roasting by British cooks, the whole is uniformly
cooked throughout without the soddening action of mere boiling or
steaming, as the excess of moisture is removed by the final current of
hot dry air thrown in by the blow-pipes, which at the same time give
the whole surface an uniform browning that can be regulated at will
without burning any portion or wasting the external fat.
Rumford’s second rule, that air be admitted only from below, and be
limited to the requirements, is so simple that no comment upon it is
needed. Although we have done so little in the improvement of domestic
fireplaces, great progress has been made in engine furnaces, blast
furnaces, and all other fireplaces for engineering and manufacturing
purposes. Every furnace engineer now fully appreciates Rumford’s
assertion that excess of cold air is a thief.
The third rule is one which, as I have already stated, stands
seriously in the way of any commercial “pushing” of Rumford’s kitchen
ranges. Those which he figures and describes are all of them masonic
structures, not ironmongery; the builder must erect them, they cannot
be bought ready-made; but, now that public attention is roused, I
believe that any builder who will study Rumford’s plans and drawings,
which are very practically made, may do good service to himself and his
customers by fitting up a few houses with true Rumford kitcheners, and
offering to reconstruct existing kitchen ranges, especially in large
houses.
The fourth rule is one that is sorely violated in the majority of
kitcheners, and without any good reason. The heat from the fire of any
kitchener, whether it be of brick or iron, should first do the work
demanding the highest temperature, viz., roasting and baking, then
proceed to the boiler or boilers, and after this be used for supplying
the bed-rooms and bath-room, and the housemaid, etc., with hot water
for general use, as Rumford did in his house at Brompton Row, where his
chimney terminated in metal pipes that passed through a water-tank at
the top of the house.
Linen-closets may also be warmed by this residual heat.
The fifth rule is also violated to an extent that renders the words
uttered by Rumford nearly a century ago as applicable now as then. He
said, “Nothing is so ill-judged as most of those attempts that are
frequently made by ignorant projectors _to force the same fire to
perform different services at the same time_.”
Note the last words, “same time.” In the uses above mentioned the
heat does different work successively, which is quite different from
the common practice of having flues to turn the flame of one fire in
opposite directions, to split its heat and make one fireplace appear to
do the work of two.
Every householder knows that the kitchen fire, whether it be an
old-fashioned open fireplace, or a modern kitchener of any improved
construction, is a very costly affair. He knows that its wasteful work
produces the chief item of his coal bill, but somehow or other he is
helpless under its infliction. If he has given any special attention to
the subject he has probably tried three or four different kinds without
finding any notable relief. Why is this? I venture to make a reply that
will cover 90 per cent, or probably 99 per cent of these cases, viz.,
that he has never considered the main source of waste, which Rumford so
clearly defines as above, and which was eliminated in all the kitchens
that he erected.
Let us suppose the case of a household of ten persons, but which in the
ordinary course of English hospitality _sometimes_ entertains twice
that number. What do we find in the kitchen arrangements? Simply that
there is one fireplace suited for the maximum requirements, _i.e._,
sufficient for twenty, even though that number may not be entertained
more than half a dozen times in the course of a year. To cook a few
rashers of bacon, boil a few eggs, and boil a kettle of water for
breakfast, a fire sufficient to cook for a dinner party of twenty is at
work. This is kept on all day long, because it is just possible that
the master of the house may require a glass of grog at bedtime. There
may be dampers and other devices for regulating this fire, but such
regulation, even if applied, does very little so long as the capacity
of the grate remains, and as a matter of ordinary fact the dampers and
other regulating devices are neglected altogether; the kitchen fire is
blazing and roaring to waste from 6 or 7 A.M. to about midnight, in
order to do about three hours and a half work, _i.e._, the dinner for
ten, and a nominal trifle for the other meals.
In Rumford’s kitchens, such as those he built for the Baron de
Lerchenfeld and for the House of Industry at Munich, the kitchener
is a solid block of masonry of work-bench height at top, and with a
deep bay in the middle, wherein the cook stands surrounded by his
boilers, steamers, roasters, ovens, etc., all within easy reach, each
one supplied by its own separate fire of very small dimensions, and
carefully closed with non-conducting doors. Each fire is lighted when
required, charged with only the quantity of fuel necessary for the work
to be done, and then extinguished or allowed to die out.
It is true that Rumford used wood, which is more easily managed in this
way than coal. If we worked as he did, we might use wood likewise,
and in spite of its very much higher price do our cooking at half
its present cost. This would effect not merely “smoke abatement” but
“smoke extinction” so far as cooking is concerned. But the lighting
of fires is no longer a troublesome and costly process as in the days
of halfpenny bundles of firewood. To say nothing of the improved
fire-lighters, we have gas everywhere, and nothing is easier than to
fix or place a suitable Bunsen or solid flame burner under each of the
fireplaces (an iron gaspipe, perforated _below_ to avoid clogging, will
do), and in two or three minutes the coals are in full blaze; then the
gas may be turned off. The writer has used such an arrangement in his
study for some years past, and starts his fire in full blaze in three
minutes quite independent of all female interference.
I have no doubt that ultimately gas will altogether supersede coal for
cooking; but this and all other scientific improvements in domestic
comfort and economy must be impossible with the present generation of
uneducated domestics, whose brains (with few exceptions) have become
torpid and wooden from lack of systematic exercise during their period
of growth.
THE “CONSUMPTION OF SMOKE.”
A great deal has been spoken and written on this subject, but
practically nothing has been _done_. At one time I shared the general
belief in its possibility, and accordingly examined a multitude of
devices for smoke-consuming, and tried several of the most promising,
chiefly in furnaces for metallurgical work, for steam boilers and
stills. None of them proved satisfactory, and I was driven to the
conclusion that smoke-consumption is a delusion, and further, that
_economical_ consumption of smoke is practically impossible. When smoke
is once formed, the cost of burning it far exceeds the value of the
heat that is produced by the combustion of its very flimsy flocculi
of carbon. It is a fiend that once raised cannot be exorcised, a
Frankenstein that haunts its maker, and will not be appeased.
To describe in detail the many ingenious devices that have been
proposed and expensively patented and advertised for this object, would
carry me far beyond the intended limits of this paper. I must not even
attempt this for a selected few, as even among them there is none that
can be pronounced satisfactory.
The common idea is that if the smoke be carried back to the fire
that produced it, and made to pass through it again, a recombustion
or consumption of the smoke will take place. This is a mistake, as a
little reflection will show. First, let us ask why did this particular
fire produce such smoke? Everybody now-a-days can answer this question,
as we all know that smoke is a result of imperfect combustion, and,
knowing this, it can easily be understood that to return the carbonic
acid and excess of carbon to the already suffocated fire can only add
smother to smotheration, and make the smoky fire more smoky still.
There is, however, one case in which a fire _appears_ to thus consume
its own smoke, but the appearance is delusive. I refer to fires lighted
from above. These, if properly managed, are practically smokeless,
and it is commonly supposed that smoke passes from the raw coal below
through the burning coal above, and is thereby consumed. The fact
is, however, that no such smoke is formed. That which under these
conditions comes from the coal beneath, when gradually heated by the
fire above, is combustible _gas_, and this gas is burned as it passes
through the fire. In this case the formation or non-formation of
smoke depends mainly on how this gas is burned, whether completely or
incompletely. If the air supplied for its combustion is insufficient,
smoke will be formed as it is when we turn up an Argand gas-flame so
high that the gas is too great in proportion to the quantity of air
that can enter the glass chimney.
Herein lies the fundamental principle. We may _prevent_ smoke, though
we cannot _cure_ it, and this prevention depends upon how we supply
air to the gas which the coal gives off when heated, and upon the
condition of this gas when we bring it in contact with the air by which
its combustion is to be effected. We must always remember that coal
when its temperature is sufficiently heated, whether in a gas retort
or fireplace, gives off a series of combustible hydrocarbon gases and
vapors, and all we have to do in order to obtain smokeless fires is to
secure the complete combustion of these.
Now we know that to burn a given quantity of gas we must supply it
with a sufficient quantity of oxygen, _i.e._, of the active principle
of the air; but this is not all: we all know well enough that if cold
coal-gas and cold air be brought together in any proportion whatever
no combustion occurs. A certain amount of heat is necessary to start
the chemical combination of oxygen with hydrogen and carbon, which
combination is the combustion, or burning.
Therefore, when the coal gas and the air are brought together one or
the other, or both, must be heated up to a certain point in order
that the combustion be complete. If cold there is no combustion; if
insufficiently heated, there is imperfect combustion, however well the
supplies may be regulated.
A very simple experiment that anybody may make illustrates this. When
an ordinary open fire is burning brightly and clearly without flame,
throw a few small pieces of raw coal into the midst of the glowing
coals. They will flame fiercely, but without smoking. Then throw a heap
of coal or one large lump on a similar fire. Now you will have dense
volumes of smoke, and little or no flame, simply because the cooling
action of the large bulk of coal in the course of distillation brings
the temperature of its gases below that required for their complete
combustion.
This simple experiment supplies a most important practical lesson,
as well as a philosophical example. The best of all smoke-abatement
machines is an intelligent and conscientious stoker, and every
contrivance for smoke abatement must, in order to be efficient, either
be fed by such a stoker or provided with some automatic arrangement by
which the apparatus itself does the work of such a stoker by supplying
the fresh fuel just when and where it is wanted.
Cornish experience is very instructive in this respect. The engines
that pump the water from the mines do a definitely measurable amount of
work, and are made to register this. The stoker is a skilled workman,
and prizes are given to those who obtain the largest amount of “duty”
from given engines per ton of coal consumed. Instead of pitching his
coal in anyhow, cramming his fire-hole, and then sitting down to sleep
or smoke in company with his chimney, the Cornish, or other good
fireman, feeds little and often, and deftly sprinkles the contents of
his shovel just where the fire is the brightest and the hottest, and
the bars are the least thickly covered. The result is remarkable. A
colliery proprietor of South Staffordshire was visiting Cornwall, and
went with a friend to see his works. On approaching the engine-house
and seeing a whitewashed shaft with no smoke issuing from its mouth,
he expressed his disappointment at finding that the engine was not at
work. To all who have been accustomed to the “Black Country,” where
coal is so shamefully wasted because it is cheap, the tall clean
whitewashed shafts of Cornwall, all so smokeless, present quite an
astonishing appearance.
This is not a result of “smoke-consuming” apparatus, but mainly of
careful firing. It was in the first place promoted by the high price
of coal due to the cost of carriage before the Cornish railways were
constructed, and it brought about a curious result. Horse-power for
horse-power the cost of fuel for working Cornish pumping engines has
been brought below that of pumping engines in the places where the
price of coal per ton was less than one-half. Another coal famine that
should raise the price of coal in London to 60_s._ per ton, and keep it
there for two or three years, would effect more smoke abatement than we
can hope to result from the present and many future South Kensington
efforts. I need scarcely dwell upon the necessity for a due supply of
air. This is well understood by everybody. An over supply of air does
mischief, by carrying away wastefully a proportionate quantity of heat.
The waste due to this is sometimes very serious.
After reviewing all that has been done, the conclusion that London
cannot become a clean, smokeless, and beautiful city, so long as we are
dependent upon open fire-grates of anything like ordinary construction,
and fed with bituminous coal, is inevitable. The general use of
anthracite would effect the desired change, but there is no hope of its
becoming general without legislative compulsion, and Englishmen will
not submit to this.
One of the most hopeful schemes is that which was propounded a short
time since by Mr. Scott Moncrieff. Instead of receiving our coal in
its crude state he proposes that we should have its smoke-producing
constituents removed before it is delivered to us; that it should
be made into a sort of artificial semi-anthracite at the gas-works
by a process of half distillation, which would take away not _all_
the flaming gas as at present, but that portion which is by far the
richest to the gas-maker and the most unmanageable in common fires.
We should thus have a material which, instead of being so difficult to
light as coke and anthracite, would light more easily than crude coal,
and at the same time our gas would have far greater illuminating power,
as it would all be drawn off during the early period of distillation,
when it is at its richest. From a given quality of coal the difference
would be as twenty-four candles to sixteen. The ammonia which we now
throw into the air, the naphtha and coal-tar products, which we waste,
are so valuable that they would pay all the expenses at the gas-works
and leave a handsome profit. We should thus get gas so much better that
two burners would do the work now obtained from three. We should get
all we require for lighting purposes and plenty more for heating; the
intermediate profits of the coal merchant would be abolished, and our
solid fuel of far better quality could be supplied twenty or thirty per
cent cheaper than at present, provided always that the gas monopoly
were abolished, “a consummation most devoutly to be wished for.”
Mr. Moncrieff (who brought forward his scheme without any
company-mongering, or claims for patent rights) estimates the saving to
London at £2,125,000 per annum, over and above the far greater saving
that would result from the abolition of smoke.
In connection with this scheme I may mention a fact that has not been
hitherto noted, viz., that we have perforce and unconsciously done a
little in this direction already. Formerly London was supplied almost
exclusively with “Wallsend” and other sea-borne coals of a highly
bituminous composition—soft coals that fused in the grate and caked
together. Partly owing to exhaustion of the seams, and partly to the
competition of railway transit, we now obtain a large proportion of
hard coal from the Midlands. This is less smoky and less sooty, and
hence the Metropolitan smoke nuisance has not increased quite as
greatly as the population.
But I will now conclude by repeating that whatever scheme be chosen,
“smoke abatement” is to be achieved, _not by smoke-consumption, but by
smoke-prevention_.
THE AIR OF STOVE-HEATED ROOMS.
Whatever opinions may be formed of the merits of the exhibits at South
Kensington, one result is unquestionable—the exhibition itself has
done much in directing public attention to the very important subject
of economizing fuel and the diminution of smoke. We sorely need some
lessons. Our national progress in this direction has been simply
contemptible, so far as domestic fireplaces are concerned.
To prove this we need only turn back to the essays of Benjamin
Thompson, Count of Rumford, published in London just eighty years
ago, and find therein nearly all that the Smoke Abatement Exhibition
_ought_ to teach us, both in theory and practice—lessons which all our
progress since 1802, plus the best exhibits at South Kensington, we
have yet to learn.
This small progress in domestic heating is the more remarkable when
contrasted with the great strides we have made in the construction and
working of engineering and metallurgical furnaces, the most important
of which is displayed in the Siemens regenerative furnace. A climax
to this contrast is afforded by a speech made by Dr. Siemens himself,
in which he defends our domestic barbarisms with all the conservative
inconvincibility of a born and bred Englishman, in spite of his German
nationality.
The speech to which I refer is reported in the “Journal of the Society
of Arts,” December 9, 1881, and contains some curious fallacies,
probably due to its extemporaneous character; but as they have been
quoted and adopted not only in political and literary journals, but
also by a magazine of such high scientific standing as _Nature_ (see
editorial article January 5, 1882, p. 219), they are likely to mislead
many.
Having already, in my “History of Modern Invention, etc.,” and in other
places, expressed my great respect for Dr. Siemens and his benefactions
to British industry, the spirit in which the following plain-spoken
criticism is made will not, I hope, be misunderstood either by the
readers of “Knowledge” or by Dr. Siemens himself.
I may further add that I am animated by a deadly hatred of our
barbarous practice of wasting precious coal by burning it in iron
fire-baskets half buried in holes within brick walls, and under
shafts that carry 80 or 90 per cent of its heat to the clouds; that
pollute the atmosphere of our towns, and make all their architecture
hideous; that render scientific and efficient ventilation of our houses
impossible; that promote rheumatism, neuralgia, chilblains, pulmonary
diseases, bronchitis, and all the other “ills that flesh is heir to”
when roasted on one side and cold-blasted on the other; that I am so
rabid on this subject, that if Dr. Siemens, Sir F. Bramwell, and all
others who defend this English abomination, were giant windmills in
full rotation, I would emulate the valor of my chivalric predecessor,
whatever might be the personal consequences.
Dr. Siemens stated that the open fireplace “communicates absolutely no
heat to the air of the room, because air, being a perfectly transparent
medium, the rays of heat pass clean through it.”
Here is an initial mistake. It is true that air which has been
artificially deprived of _all_ its aqueous vapor is thus completely
permeable by heat rays, but such is far from being the case with
the water it contains. This absorbs a notable amount even of bright
solar rays, and a far greater proportion of the heat rays from a
comparatively obscure source, such as the red-hot coals and flame of a
common fire. Tyndall has proved that 8 to 10 per cent of all the heat
radiating from such a source as a common fire is absorbed in passing
through only 5 feet of air in its ordinary condition, the variation
depending upon its degree of saturation with aqueous vapor.
Starting with the erroneous assumption that the rays of heat pass
“clean through” the air of the room, Dr. Siemens went on to say that
the open fireplace “gives heat only by heating the walls, ceiling, and
furniture, and here is the great advantage of the open fire;” and,
further, that “if the air in the room were hotter than the walls,
condensation would take place on them, and mildew and fermentation of
various kinds would be engendered; whereas, if the air were cooler than
the walls, the latter must be absolutely dry.”
Upon these assumptions, Dr. Siemens condemns steam-pipes and stoves,
hot-air pipes, and all other methods of directly heating the _air_
of apartments, and thereby making it warmer than were the walls, the
ceiling, and furniture when the process of warming commenced. It is
quite true that stoves, stove-pipes, hot-air pipes, steam-pipes,
etc., do this; they raise the temperature of the air directly by
_convection_, _i.e._, by warming the film of air in contact with their
surfaces, which film, thus heated and expanded, rises towards the
ceiling, and, on its way, warms the air around it, and then is followed
by other similarly-heated ascending films. When we make a hole in the
wall, and burn our coals within such cavity, this convection proceeds
up the chimney in company with the smoke.
But is Dr. Siemens right in saying that the air of a room, raised by
convection above its original temperature, and above that of the walls,
deposits any of its moisture on these walls? I have no hesitation in
saying very positively that he is clearly and demonstrably wrong; that
no such condensation can possibly take place under the circumstances.
Suppose, for illustration sake, that we start with a room of which the
air and walls are at the freezing point, 32° F., before artificial
heating (any other temperature will do), and, to give Dr. Siemens every
advantage, we will further suppose that the air is fully saturated
with aqueous vapor, _i.e._, just in the condition at which some of its
water might be condensed. Such condensation, however, can only take
place by cooling the air _below_ 32°, and unless the walls or ceiling
or furniture are capable of doing this they cannot receive any moisture
due to such condensation, or, in other words, they must fall below
32° in order to obtain it by cooling the film in contact with them.
Of course Dr. Siemens will not assert that the stoves or steam-pipes
(enclosing the steam, of course), or the hot-air or hot-water pipes,
will lower the _absolute_ temperature of the walls by heating the air
in the room.
But if the air is heated more rapidly than are the walls, etc., the
_relative_ temperature of these will be lower. Will condensation of
moisture _then_ follow, as Dr. Siemens affirms? Let us suppose that
the air of the room is raised from 30° to 50° _by convection purely_;
reference to tables based on the researches of Regnault, shows that at
32° the quantity of vapor required to saturate the air is sufficient to
support a column of 0·182 inch of mercury, while at 50° it amounts to
0·361, or nearly double. Thus the air, instead of being in a condition
of giving away its moisture to the walls, has become thirsty, or in a
condition to _take moisture away from them_ if they are at all damp.
This is the case whether the walls remain at 32° or are raised to any
higher temperature short of that of the air.
Thus the action of close stoves and of hot surfaces or pipes of any
kind is exactly the opposite of that attributed to them by Dr. Siemens.
They dry the air, they dry the walls, they dry the ceiling, they dry
the furniture and everything else in the house.
In _our_ climate, especially in the infamous jerry-built houses of
suburban London, this is a great advantage. Dr. Siemens states his
American experience, and denounces such heating by convection because
the close stoves _there_ made him uncomfortable. This was due to the
fact that the winter atmosphere of the United States is very dry, even
when at zero. But air, when raised from 0° to 60°, acquires about
twelve times its original capacity for water. The air thus simply
heated is desiccated, and it desiccates everything in contact with it,
especially the human body. The lank and shriveled aspect of the typical
Yankee is, I believe, due to this. He is a desiccated Englishman, and
we should all grow like him if our climate were as dry as his.[30] The
great fires that devastate the cities of the United States appear to
me to be due to this general desiccation of all building materials,
rendering them readily inflammable and the flames difficult of
extinction.
When an undesiccated Englishman, or a German endowed with a wholesome
John Bull rotundity, is exposed to this superdried air, he is subjected
to an amount of bodily evaporation that must be perceptible and
unpleasant. The disagreeable sensation experienced by Dr. Siemens in
the stove-heated railway cars, etc., were probably due to this.
An English house, enveloped in a foggy atmosphere, and encased in
damp surroundings, especially requires stove-heating, and the most
inveterate worshipers of our national domestic fetish, the open grate,
invariably prefer a stove or hot-pipe-heated room, when they are
unconscious of the source of heat, and their prejudice hoodwinked.
I have observed this continually, and have often been amused at the
inconsistency thus displayed. For example, one evening I had a warm
contest with a lady, who repeated the usual praises of a cheerful
blaze, etc., etc. On calling afterwards, on a bitter snowy morning, I
found her and her daughters sitting at work in the billiard-room, and
asked them why. “Because it is so warm and comfortable.” This room was
heated by an eight-inch steam-pipe, running around and under the table,
to prevent the undue cooling of the indiarubber cushions, and thus the
room was warmed from the middle, and equally and moderately throughout.
The large reception-room, with blazing fire, was scorching on one side,
and freezing on the other, at that time in the morning.
The permeability of ill-constructed iron stoves to poisonous carbonic
oxide, which riddles through red-hot iron, is a real evil, but easily
obviated by proper lining, The frizzling of particles of organic
matter, of which we hear so much, is—if it really does occur—highly
advantageous, seeing that it must destroy organic poison-germs.
Under some conditions, the warm air of a room _does_ deposit moisture
on its cooler walls. This happens in churches, concert-rooms, etc.,
when they are but occasionally used in winter time, and mainly warmed
by animal heat, by congregational emanations of breath-vapor, and
perspiration—_i.e._, with warm air supersaturated with vapor. Also,
when we have a sudden change from dry, frosty weather to warm and
humid. Then our walls may be streaming with condensed water. Such cases
were probably in the mind of Dr. Siemens when he spoke; but they are
quite different from stove-heating or pipe-heating, which increase
the vapor capacity of the heated air, without supplying the demand it
creates.
VENTILATION BY OPEN FIREPLACES.
The most stubborn of all errors are those which have been acquired
by a sort of inheritance, which have passed dogmatically from father
to son, or, still worse, from mother to daughter. They may become
superstitions without any theological character. The idea that the
weather changes with the moon, that wind “keeps off the rain,” are
physical superstitions in all cases where they are blindly accepted and
promulgated without any examination of evidence.
The idea that our open fireplaces are necessary for ventilation is one
of these physical superstitions, which is producing an incalculable
amount of physical mischief throughout Britain. A little rational
reflection on the natural and necessary movements of our household
atmospheres demonstrates at once that this dogma is not only baseless,
but actually expresses the opposite of the truth. I think I shall be
able to show in what follows, 1st, that they do no useful ventilation;
and, 2d, that they render systematic and really effective ventilation
practically impossible.
Everybody knows that when air is heated it expands largely, becomes
lighter, bulk for bulk, than other air of lower temperature; and
therefore, if two portions of air of unequal temperatures, and free
to move, are in contact with each other, the colder will flow under
the warmer, and push it upwards. The latter postulate must be kept
distinctly in view, for the rising of warm air is too commonly regarded
as due to some direct uprising activity or skyward affinity of its own,
instead of being understood as an indirect result of gravitation. It
is the downfalling of the cooler air that causes the uprising of the
warmer.
Now, let us see what, in accordance with the above-stated simple
laws, must happen in an ordinary English apartment that is fitted,
as usual, with one or more windows more or less leaky, and one or
more doors in like condition, and a hole in the wall in which coal
is burning in an iron cage immediately beneath a shaft that rises to
the top of the house, the fire-hole itself having an extreme height
of only 24 to 30 inches above the floor, all the chimney above this
height being entirely closed. (I find by measurement that 24 inches
is the usual height of the upper edge of the chimney opening of an
ordinary “register” stove. Old farm-house fireplaces are open to the
mantlepiece.)
Now, what happens when a heap of coal is burning in this hole? Some of
the heat—from 10 to 20 per cent, according to the construction of the
grate—is radiated into the room, the rest is conveyed by an ascending
current of air up the chimney. As this ascending current is rendered
visible by the smoke entangled with it, no further demonstration of its
existence is needed.
But how is it pushed up the chimney? Evidently by cooler air, that
flows into the room from somewhere, and which cooler air must get
under it in order to lift it. In ordinary rooms this supply of air is
entirely dependent upon their defective construction—bad joinery;
it enters only by the crevices surrounding the ill-fitting windows
and doors, no specially designed opening being made for it. Usually
the chief inlet is the space under the door, through which pours a
rivulet of cold air, that spreads out as a lake upon the floor. This
may easily be proved by holding a lighted taper in front of the bottom
door-chink when the window and other door—if any—are closed, and the
fire is burning briskly. At the same time more or less of cold air is
poured in at the top and the side spaces of the door and through the
window-chinks. The proportion of air entering by these depends upon the
capacity of the bottom door-chink. If this is large enough it will do
nearly all the work, otherwise every other possible leakage, including
the key-hole, contributes.
But what is the path of the air which enters by these higher level
openings? The answer to this is supplied at once by the fact that
such air being colder than that of the room, it must fall immediately
it enters. The rivulet under the door is thus supplemented by cascades
pouring down from the top and sides of the door and the top and sides
of the windows, all being tributaries to the lake of cold air covering
the floor.
The next question to be considered is, what is the depth of this lake?
In this, as in every other such accumulation of either air or water,
the level of the upper surface of the lake is determined by that of its
outlet. The outlet in this case is the chimney hole, through which all
the overflow pours upwards; and, therefore, the surface of the flowing
stratum of cold air corresponds with the upper part of the chimney
hole, or of the register, where register stoves are used.
Below this level there is abundant ventilation, above it there is none.
The cat that sits on the hearth-rug has an abundant supply of fresh
air, and if we had tracheal breathing apertures all down the sides
of our bodies, as caterpillars have, those on our lower extremities
might enjoy the ventilation. If we squatted on the ground like savages
something might be said for the fire-hole ventilator. But as we are
addicted to sitting on chairs that raise our breathing apparatus
considerably above the level of the top of the register, the maximum
efficiency of the flow of cold air in the lake below is expressed by
the prevalence of chilblains and rheumatism.[31]
The atmosphere in which our heads are immersed is practically stagnant;
the radiations from the fire, plus the animal heat from our bodies,
just warm it sufficiently to enable the cool entering air to push it
upwards above the chimney outlet and the surface of the lower moving
stratum, and to keep it there in a condition of stagnation.
If anybody doubts the correctness of this description, he has only to
sit in an ordinary English room where a good fire is burning—the doors
and windows closed, as usual—and then to blow a cloud by means of
pipe, cigar, or by burning brown paper or otherwise, when the movements
below and the stagnation above, which I have described, will be
rendered visible. If there is nobody moving about to stir the air, and
the experiment is fairly made, the level of the cool lake below will be
distinctly shown by the clearing away of the smoke up to the level of
the top of the register opening, towards which it may be seen to sweep.
Above this the smoke-wreaths will remain merely waving about, with
slight movements due to the small inequalities of temperature caused
by the fraction of heat radiated into the room from the front of the
fire. These movements are chiefly developed near the door and windows,
where the above-mentioned cascades are falling, and against the walls
and furniture, where feeble convection currents are rising, due to the
radiant heat absorbed by their surfaces. The stagnation is the most
complete about the middle of the room, where there is the greatest bulk
of vacant airspace.
When the inlet under the door is of considerable dimensions, there
may be some escape of warmer upper air at the top of the windows, if
their fitting is correspondingly defective. These, however, are mere
accidents; they are not a part of the vaunted chimney-hole ventilation,
but interferences with it.
There is another experiment that illustrates the absence of ventilation
in such rooms where gas is burning. It is that of suspending a canary
in a cage near the roof. But this is cruel; it kills the bird. It would
be a more satisfactory experiment to substitute for the canary-bird any
wingless biped who, after reading the above, still maintains that our
fire-holes are effective ventilators.
Not only are the fire-holes worthless and mischievous ventilators
themselves, but they render efficient ventilation by any other means
practically impossible. The “Arnott’s ventilator” that we sometimes see
applied to the upper part of chimneys is marred in its action by the
greedy “draught” below.
The tall chimney-shaft, with a fire burning immediately below it,
dominates all the atmospheric movement in the house, unless another and
more powerful upcast shaft be somewhere else in communication with the
apartments. But in this case the original or ordinary chimney would be
converted into a downcast shaft pouring air downwards into the room,
instead of carrying it away upwards. I need not describe the sort of
ventilation thus obtainable while the fire is burning and smoking.
Effective sanitary ventilation should supply gentle and
uniformly-diffused currents of air of moderate and equal temperature
throughout the house. We talk a great deal about the climate here
and the climate there; and when we grow old, and can afford it, we
move to Bournemouth, Torquay, Mentone, Nice, Algiers, etc., for
better climates, forgetting all the while that the climate in which
we practically live is not that out-of-doors, but the indoor climate
of our dwellings, the which, in a properly constructed house, may
be regulated to correspond to that of any latitude we may choose.
I maintain that the very first step towards the best attainable
approximation to this in our existing houses is to brick up, cement
up, or otherwise completely stop up, all our existing fire-holes, and
abolish all our existing fires.
But what next? The reply to this will be found in the next chapter.
DOMESTIC VENTILATION.
A LESSON FROM THE COAL-PITS.
We require in our houses an artificial temperate climate which shall
be uniform throughout, and at the same time we need a gentle movement
of air that shall supply the requirements of respiration without any
gusts, or draughts, or alternations of temperature. Everybody will
admit that these are fundamental _desiderata_, but whoever does so
becomes thereby a denouncer of open-grate fireplaces, and of every
system of heating which is dependent on any kind of stoves with
fuel burning in the rooms that are to be inhabited. All such devices
concentrate the heat in one part of each room, and demand the admission
of cold air from some other part or parts, thereby violating the
primary condition of uniform temperature. The usual proceeding effects
a specially outrageous violation of this, as I showed in the last
chapter.
I might have added domestic cleanliness among the _desiderata_;
but in the matter of fireplaces, the true-born Briton, in spite of
his fastidiousness in respect to shirt-collars, etc., is a devoted
worshiper of dirt. No matter how elegant his drawing-room, he must
defile it with a coal-scuttle, with dirty coals, poker, shovel, and
tongs, dirty ash-pit, dirty cinders, ashes, and dust, and he must amuse
himself by doing the dirty work of a stoker towards his “cheerful,
companionable, pokeable” open fire.
It is evident that, in order to completely fulfil the first-named
requirements, we must, in winter, supply our model residence with
fresh artificially-warmed air, and in summer with fresh cool air. How
is this to be done? An approach to a practical solution is afforded
by examining what is actually done under circumstances where the
ventilation problem presents the greatest possible difficulties, and
where, nevertheless, these difficulties have been effectually overcome.
Such a case is presented by a deep coal mine. Here we have a little
working world, inhabited by men and horses, deep in the bowels of
the earth, far away from the air that must be supplied in sufficient
quantities, not only to overcome the vitiation due to their own
breathing, but also to sweep out the deadly gaseous emanations from the
coal itself.
Imagine your dwelling-house buried a quarter of a mile of perpendicular
depth below the surface of the earth, and its walls giving off
suffocating and explosive gases in such quantities that steady and
abundant ventilation shall be a matter of life or death, and that in
spite of this it is made so far habitable that men who spend half their
days there retain robust health and live to green old age, and that
horses after remaining there day and night for many months actually
improve in condition. Imagine, further, that the house thus ventilated
has some hundreds of small, very low-roofed rooms, and a system of
passages or corridors with an united length of many miles, and that its
inhabitants count by hundreds.
Such dwellings being thus ventilated and rendered habitable for man and
beast, it is idle to dispute the practical possibility of supplying
fresh air of any given temperature to a mere box of brick or stone,
standing in the midst of the atmosphere, and containing but a few
passages and apartments.
The problem is solved in the coal-pit by simply and skilfully
controlling and directing the natural movements of unequally-heated
volumes of air. Complex mechanical devices for forcing the ventilation
by means of gigantic fan-wheels, etc., or by steam-jets, have been
tried, and are now generally abandoned. An inlet and an outlet are
provided, _and no air is allowed to pass inwards or outwards by any
other course than that which has been pre-arranged for the purposes of
efficient ventilation_. I place especial emphasis on this condition,
believing that its systematic violation is the primary cause of the
bungling muddle of our domestic ventilation.
Let us suppose that we are going to open a coal-pit to mine the coal
on a certain estate. We first ascertain the “dip” of the seam, or its
deviation from horizontality, and then start at the _lowest_ part,
not, as some suppose, at that part nearest to the surface. The reason
for this is obvious on a little reflection, for if we began at the
shallowest part of an ordinary water-bearing stratum we should have
to drive down under water; but, by beginning at the lowest part and
driving upwards, we can at once form a “sumpf,” or bottom receptacle,
to receive the drainage, and from which the accumulated water may be
pumped. This, however, is only by the way, and not directly connected
with our main subject, the ventilation.
In order to secure this, the modern practice is to sink two pits, “a
pair,” as they are called, side by side, at any convenient distance
from each other. If they are deep, it becomes necessary to commence
ventilation of the mere shafts themselves in the course of sinking.
This is done by driving an air-way—a horizontal tunnel from one to
the other, and then establishing an “upcast” in one of them by simply
lighting a fire there. This destroys the balance between the two
communicating columns of air; the cooler column in the shaft without a
fire, being heavier, falls against the lighter column, and pushes it up
just as the air is pushed up one leg of an =U= tube when we pour water
down the other. Even in this preliminary work, if the pits are so deep
that more than one air-way is driven, it is necessary to stop the upper
ways and leave only the lowest open, in order that the ventilation
shall not take a short and useless cut, as it does up our fireplace
openings.
Let us now suppose that the pair of pits are sunk down to the seam,
with a further extension below to form the water sumpf. There are two
chief modes of working a coal-seam: the “pillar and stall” and the
“long wall,” or more modern system. For present illustration, I select
the latter as the simplest in respect to ventilation. This method, as
ordinarily worked, consists essentially in first driving roads through
the coal, from the pits to the outer boundary of the area to be worked,
then cutting a cross road that shall connect these, thereby exposing a
“long wall” of coal, which, in working, is gradually cut away towards
the pits, the roof remaining behind being allowed to fall in.
Let us begin to do this by driving, first of all, two main roads, one
from each pit. It is evident that as we proceed in such burrowing, we
shall presently find ourselves in a _cul de sac_ so far away from the
outer air that suffocation is threatened. This will be equally the case
with both roads. Let us now drive a cross-cut from the end of each
main road, and thus establish a communication from the downcast shaft
through its road, then through the drift to the upcast road and pit.
But in order that the air shall take this roundabout course, we must
close the direct drift that we previously made between the two shafts,
or it will proceed by that shorter and easier course. Now we shall have
air throughout both our main roads, and we may drive on further, until
we are again stopped by approximate suffocation. When this occurs,
we make another cross-cut, but in order that it may act we must stop
the first one. So we go on until we reach the working, and then the
long wall itself becomes the cross communication, and through this
working-gallery the air sweeps freely and effectually.
In the above I have only considered the simplest possible elements of
the problem. The practical coal-pit in full working has a multitude
of intervening passages and “splits,” where the main current from the
downcast is divided, in order to proceed through the various streets
and lanes of the subterranean town as may be required, and these
divided currents are finally reunited ere they reach the upcast shaft
which casts them all out into the upper air.
In a colliery worked on the pillar and stall system—_i.e._, by taking
out the coal so as to leave a series of square chambers with pillars of
coal in the middle to support the roof—the windings of the air between
the multitude of passages is curiously complex, and its absolute
obedience to the commands of the mining engineer proves how completely
the most difficult problems of ventilation may be solved when ignorance
and prejudice are not permitted to bar the progress of the practical
applications of simple scientific principles.
Here the necessity of closing all false outlets is strikingly
demonstrated by the mechanism and working of the “stoppings” or
partitions that close all unrequired openings. The air in many pits has
to travel several miles in order to get from the downcast to the upcast
shaft, though they may be but a dozen yards apart. (Formerly the same
shaft served both for up and down cast, by making a wooden division
(a _brattice_) down the middle. This is now prohibited, on account
of serious accidents that have been caused by the fracture of the
_brattice_.)
But it would not do to carry the coal from the workings to the pit
by these sinuous air-courses. What, then, is done? A direct road is
made for the coal, but if it were left open, the air would choose
it: this is prevented by an arrangement similar to that of canal
locks. Valve-doors or “stoppings” are arranged in pairs, and when
the “hurrier” arrives with his _corve_, or pit carriage, one door is
opened, the other remaining shut; then the _corve_ is hurried into
the space between the doors, and the entry-door is closed; now the
exit-door is opened, and thus no continuous opening is ever permitted.
Only one such opening would derange the ventilation of the whole pit,
or of that portion fed by the split thus allowed to escape. It would,
in fact, correspond to the action of our open fireplaces in rendering
effective ventilation impossible.
The following, from the report of the Lords’ Committee on Accidents
in Coal Mines, 1849, illustrates the magnitude of the ventilation
arrangements then at work. In the Hetton Colliery there were two
downcast shafts and one upcast, the former about 12 feet and the latter
14 feet diameter. There were three furnaces at the bottom of the
upcast, each about 9 feet wide with about 4 feet length of grate-bars;
the depth of the upcast and one downcast 900 feet, and of the other
downcast 1056 feet. The quantity of air introduced by the action of
these furnaces was 168,560 cubic feet per minute, at a cost of about
eight tons of coal per day. The rate of motion of the air was 1097 feet
per minute (above 12 miles per hour). This whole current was divided by
splitting into 16 currents of about 11,000 cubic feet each per minute,
having, on an average, a course of 4¼ miles each. This distance was,
however, very irregular—the greatest length of course being 9-1/10
miles; total length 70 miles. Thus 168,560 cubic feet of air were
driven through these great distances at the rate of 12 miles per hour,
and at a cost of 8 tons of coal per day.
All these magnitudes are greatly increased in coal-mines of the present
time. As much as 250,000 cubic feet of air per minute are now passed
through the shafts of one mine.
The problem of domestic ventilation as compared with coal-pit
ventilation involves an additional requirement, that of warming, but
this does not at all increase the difficulty, and I even go so far as
to believe that cooling in summer may be added to warming in winter by
one and the same ventilating arrangement. As I am not a builder, and
claim no patent rights, the following must be regarded as a general
indication, not as a working specification, of my scheme for domestic
ventilation and the regulation of home climate.
The model house must have an upcast shaft, placed as nearly in the
middle of the building as possible, with which every room must
communicate either by a direct opening or through a lateral shaft. An
ordinary chimney built in the usual manner is all that is required to
form such a main shaft.
There must be no stoves nor any fireplaces in any room excepting the
kitchen, of which anon. All the windows must be made to fit closely,
as nearly air-tight as possible. No downcast shaft is required, the
pressure of the surrounding outer atmosphere being sufficient. Outside
of the house, or on the ground floor (on the north side, if possible),
should be a chamber heated by flues, hot air, steam, a suitable stove,
or water-pipes, and with one adjustable opening communicating with the
outer fresh air, and another on the opposite side connected by a shaft
or air-way with the hall of the ground floor and the general staircase.
Each room to have an opening at its upper part communicating with
the chimney, like an Arnott’s ventilator, and capable of adjustment
as regards area of aperture, and other openings of corresponding or
excessive combined area leading from the hall or staircase to the lower
part of the room. These may be covered with perforated zinc or wire
gauze, so that the air may enter in a gentle, broken stream.
All the outer house-doors must be double, _i.e._, with a porch or
vestibule, and only one of each pair of doors opened at once. These
should be well fitted, and the staircase air-tight. The kitchen to
communicate with the rest of the house by similar double doors, and the
kitchen fire to communicate directly with the upcast shaft or chimney
by as small a stove-pipe as practicable. The kitchen fire will thus
start the upcast and commence the draught of air from the warm chamber
through the house towards the several openings into the shaft. In cold
weather, this upcast action will be greatly reinforced and maintained
by the general warmth of all the air in the house, which itself will
bodily become an upcast shaft immediately the inner temperature exceeds
that of the air outside.
But the upcast of warm air can only take place by the admission of
fresh air through the heating chamber, thence to hall and staircase,
and thence onward through the rooms into the final shaft or chimney.
The openings into and out of the rooms being adjustable, they may be so
regulated that each shall receive an equal share of fresh warm air; or,
if desired, the bedroom chimney valves may be closed in the daytime,
and thus the heat economized by being used only for the day rooms; or,
_vice versâ_, the communication between the upcast shaft and the lower
rooms may be closed in the evening, and thus all the warm air be turned
into the bedrooms at bedtime.
If the area of the entrance apertures of the rooms exceeds that of the
outlet, only the latter need be adjusted; the room doors may, in fact,
be left wide open without any possibility of “draught,” beyond the
ventilation current, which is limited by the dimension of the opening
from the room into the shaft or chimney.
So far, for winter time, when the ventilation problem is the easiest,
because then the excess of inner warmth converts the whole house into
an upcast shaft, and the whole outer atmosphere becomes a downcast. In
the summer time, the kitchen fire would probably be insufficient to
secure a sufficiently active upcast.
To help this there should be in one of the upper rooms—say an
attic—an opening into the chimney secured by a small well-fitting
door; and altogether enclosed within the chimney a small automatic
slow-combustion stove (of which many were exhibited in South
Kensington, that require feeding but once in twenty-four hours), or a
large gas-burner. The heating-chamber below must now be converted into
a cooling chamber by an arrangement of wet cloths, presently to be
described, so that all the air entering the house shall be reduced in
temperature.
Or the winter course of ventilation may be reversed by building a
special shaft connected with the kitchen fire, which, in this case,
must not communicate with the house shaft. This special shaft may thus
be made an upcast, and the rooms supplied with air from above down the
house shaft, through the rooms, and out of the kitchen _viâ_ the winter
heating-chamber, which now has its communication with the outside air
closed.
Reverting to the first-named method, which I think is better than the
second, besides being less expensive, I must say a few concluding words
on an important supplementary advantage which is obtainable wherever
all the air entering the house passes through one opening, completely
under control, like that of our heating-chamber. The great evil of our
town atmosphere is its dirtiness. In the winter it is polluted with
soot particles; in the dry summer weather, the traffic and the wind
stir up and mix with it particles of dust, having a composition that
is better ignored, when we consider the quantity of horse-dung that is
dried and pulverized on our roadways. All the dust that falls on our
books and furniture was first suspended in the air we breathe inside
our rooms. Can we get rid of any practically important portion of this?
I am able to answer this question, not merely on theoretical grounds,
but as a result of practical experiments described in the following
chapter, in which is reprinted a paper I read at the Society of Arts,
March 19, 1879, recommending the enclosure of London back yards with
a roofing of “wall canvas,” or “paperhanger’s canvas,” so as to form
cheap conservatories. This canvas, which costs about threepence per
square yard, is a kind of coarse, strong, fluffy gauze, admitting light
and air, but acting very effectively as an air filter, by catching and
stopping the particles of soot and dust that are so fatal to urban
vegetation.
I propose, therefore, that this well-tried device should be applied at
the entrance aperture of our heating chamber, that the screens shall
be well wetted in the summer, in order to obtain the cooling effect of
evaporation, and in the winter shall be either wet or dry, as may be
found desirable. The Parliament House experiments prove that they are
good filters when wetted, and mine that they act similarly when dry.
By thus applying the principles of colliery ventilation to a
specially-constructed house, we may, I believe, obtain a perfectly
controllable indoor climate, with a range of variation not exceeding
four or five degrees between the warmest and the coldest part of the
house, or eight or nine degrees between summer and winter, and this
may be combined with an abundant supply of fresh air everywhere, all
filtered from the grosser portions of its irritant dust, which is
positively poisonous to delicate lungs, and damaging to all. The cost
of fuel would be far less than with existing arrangements, and the
labor of attending to the one or two fires and the valves would also
be less than that now required in the carrying of coal-scuttles, the
removal of ashes, the cleaning of fireplaces, and the curtains and
furniture they befoul by their escaping dust and smoke.
It is obvious that such a system of ventilation may even be applied
to existing houses by mending the ill-fitting windows, shutting up
the existing fire-holes, and using the chimneys as upcast shafts in
the manner above described. This may be done in the winter, when the
problem is easiest, and the demand for artificial climate the most
urgent; but I question the possibility of summer ventilation and
tempering of climate in anything short of a specially-built house
or a materially altered existing dwelling. There are doubtless some
exceptions to this, where the house happens to be specially suitable
and easily adapted, but in ordinary houses we must be content with the
ordinary devices of summer ventilation by doors and windows, plus the
upper openings of the rooms into the chimneys expanded to their full
capacity, and thus doing, even in summer, far better ventilating work
than the existing fire-holes opening in the wrong place.
I thus expound my own scheme, not because I believe it to be perfect,
but, on the contrary, as a suggestive project to be practically amended
and adapted by others better able than myself to carry out the details.
The feature that I think is novel and important is that of consciously
and avowedly applying to domestic ventilation the principles that have
been so successfully carried out in the far more difficult problem of
subterranean ventilation.
The dishonesty of the majority of the modern builders of suburban
“villa residences” is favorable to this and other similar radical
household reforms, as thousands of these wretched tenements must sooner
or later be pulled down, or will all come down together without any
pulling the next time we experience one of those earthquake tremors
which visit England about once in a century.
HOME GARDENS FOR SMOKY TOWNS.
The poetical philanthropists of the shepherd and shepherdess school,
if any still remain, may find abundant material for their doleful
denunciations of modern civilization on journeying among the house-tops
by any of our over-ground metropolitan and suburban railways, and
contemplating therefrom the panorama presented by a rapid succession of
London back yards. The sandy Sahara, and the saline deserts of Central
Asia, are bright and breezy, rural and cheerful, compared with these
foul, soot-smeared, lumber-strewn areas of desolation.
The object of this paper is to propose a remedy for these metropolitan
measle-spots, by converting them into gardens that shall afford both
pleasure and profit to all concerned.
A very obvious mode of doing this would be to cover them with glass,
and thus convert them into winter gardens or conservatories. The cost
of this at once places it beyond practical reach; but even if the cost
were disregarded, as it might be in some instances, such covering in
would not be permissible on sanitary grounds; for, doleful and dreary
as they are, the back yards of London perform one very important
and necessary function; they act as ventilation-shafts between the
house-backs of the more densely populated neighborhoods.
At one time I thought of proposing the establishment of horticultural
home missions for promoting the dissemination of flower-pot shrubs in
the metropolis, and of showing how much the atmosphere of London would
be improved if every London family had one little sweetbriar bush,
a lavender plant, or a hardy heliotrope to each of its members; so
that a couple of million of such ozone generators should breathe their
sweetness into the dank and dead atmosphere of the denser central
regions of London.
A little practical experience of the difficulty of growing a clean
cabbage, or maintaining alive any sort of shrub in the midst of our
soot-drizzle, satisfied me that the mission would fail, even though the
sweetbriars were given away by the district visitors; for these simple
hardy plants perish in a mid-London atmosphere unless their leaves are
periodically sponged and syringed, to wash away the soot particles that
otherwise close their stomata and suffocate the plant.
It is this deposit that stunts or destroys all our London vegetation,
with the exception of those trees which, like the planes have a
deciduous bark and cuticle.
Some simple and inexpensive means of protecting vegetation from London
soot are, therefore, most desirable.
When the Midland Institute commenced its existence in temporary
buildings in Cannon Street, Birmingham, in 1854, I was compelled to
ventilate my class-rooms by temporary devices, one of which was to
throw open the existing windows, and protect the students from the
heavy blast of entering air by straining it through a strong gauze-like
fabric stretched over the opening.
After a short time the tammy became useless for its intended purpose;
its interstices were choked with a deposit of carbon. On examining
this, I found that the black deposit was all on the outside, showing
that a filtration of the air had occurred. Even when the tammy was
replaced by perforated zinc, puttied into the window frames in the
place of glass panes, it was found necessary to frequently wash the
zinc, in order to keep the perforations open.
The recollection of this experience suggested that if a gauze-like
fabric, cheaper and stronger than the tammy, can be obtained, and a
sort of greenhouse made with this in the place of glass, the problem of
converting London back-yards into gardens might be solved.
After some inquiries and failures in the trial of various cheap
fabrics, I found one that is already to be had, and well adapted to the
purpose. It is called “wall canvas,” or “scrim,” is retailed at 3½_d._
per yard, and is one yard wide. If I am rightly informed, it may be
bought in wholesale quantities at about 2¼_d._ per square yard, _i.e._,
one farthing per square foot. This fabric is made of coarse unbleached
thread yarn, very strong and open in structure. The light passes so
freely through it that when hung before a window the loss of light in
the room is barely perceptible. When a piece is stretched upon a frame,
a printed placard, or even a newspaper, may be read through it.
The yarn being loosely spun, fine fluffy filaments stand out and bar
the interstices against the passage of even very minute carbonaceous
particles. These filaments may be seen by holding it up to the light.
The fabric being one yard wide, and of any length required, all that
is needed for a roof or side walls is a skeleton made of lines or runs
of quartering, at 3 feet distance from each other. The cost of such
quartering, made of pitch pine, the best material for outside work,
is under one penny per foot run; of common white deal, about three
farthings. Thus the cost of material for a roof, say a lean-to from
a wall-top to the side of a house, which would be the most commonly
demanded form of 30 feet by 10 feet, _i.e._, 300 square feet, would be—
_s._ _d._
110 feet of quartering (11 lengths) at 1_d._ 9 2
300 square feet of canvas, at 1¼ 6 3[32]
Nails and tacks, say 1 0
---------
16 5
The size of the quartering proposed is 2½ by 1¼ inch, which, laid
edgewise, would bear the weight of a man on a plank while nailing down
the canvas. The canvas has a stout cord-like edge or selvage, that
holds the nails well.
I find that what are called “French tacks” are well suited for nailing
it down. They are made of wire, well pointed, have good-sized flat
clout heads, and are very cheap. They are incomparably superior to the
ordinary rubbish sold as “tin tacks” or “cut tacks.” The construction
of such a conservatory is so simple that any industrious artisan or
clerk with any mechanical ingenuity could, with the aid of a boy, do
it all himself. No special skill is required for any part of the work,
and no other tools than a rule, a saw, and a hammer. Side posts and
stronger end rails would in some cases be demanded.
I have not been able to fairly carry out this project, inasmuch as I
reside at Twickenham, beyond the reach of the black showers of London
soot. I have, however, made some investigations relative to the climate
which results from such enclosure.
This was done by covering a small skeleton frame with the canvas,
putting it upon the ground over some cabbage plants, etc., and placing
registering thermometers on the ground inside, and in similar position
outside the frame; also by removing the glass cover of a cucumber
frame, and replacing it by a frame on which the canvas is stretched.
I planted 300 cabbages in November last, in rows on the open ground,
and placed the canvas-covered frame over 18 of them. At the present
date, March 15, only 26 of the 282 outside plants are visible above the
ground. All the rest have been cut off by the severe frost. Under the
frame _all_ are flourishing.
I find that the difference between the maximum and the minimum
temperatures varies with the condition of the sky. In cloudy weather,
the difference between the inside and the outside rarely exceeds 2°
Fahr., and occasionally there is no difference. In clear weather the
difference is considerable. During the day the outside thermometer
registers from four or five to seven or eight degrees above that within
the screen during the sunshine. At night the minimum thermometers show
a difference which in one case reached 14°, _i.e._, between 23d and
24th February, when the lowest temperature I have observed was reached.
The outside thermometer then fell to 8° Fahr., the inside to 22°. On
the night of the 24th and 25th they registered 15½° outside, 25½°
inside. On other, or ordinary clear frosty nights, with E. and N. and
N.E. winds, the difference has ranged between 4° and 6°, usually within
a fraction of the average, 5°.
The uniformity of this during the recent bright frosty nights, followed
by warm sunny days, has been very remarkable, so much so that I think I
may venture to state that 5° may be expected as the general protecting
effect of a covering of such canvas from the mischievous action of our
spring frosts which are due to nocturnal radiation into free space.
Thus we obtain a climate, the mean of which would be about the same
as outside, but subject to far less variation. How will this affect
the growth of plants desirable to cultivate in the proposed canvas
conservatories?
In the first place, we must not expect the results obtainable under
glass, which by freely transmitting the bright solar rays, and
absorbing or resisting the passage of the obscure rays from the
heated soil, produces, during sunshine, a tropical climate here in
our latitudes. We may therefore at once set aside any expectation of
rearing exotic plants of any kind; even our native and acclimatized
plants, which require the maximum heat of English sunshine, are not
likely to flourish.
On the other hand, all those which demand moderate protection from
sudden frosts, especially from spring frosts, and which flourish when
we have a long mild spring and summer, are likely to be reared with
especial success.
This includes nearly all our table vegetables, our salads, kitchen
herbs, and British fruits, all our British and many exotic ferns, and,
I believe, most of our out-of-door plants, both wild and cultivated.
As the subject of ornamental flowers is a very large one, and one with
the cultivation of which I have very little practical acquaintance, I
will pass it over; but must simply indicate that, in respect to ferns,
the canvas enclosure offers a combination of most desirable conditions.
The slight shade, the comparatively uniform temperature, and the
moderated exhalation, are just those of a luxuriant fern dingle.
Respecting the useful or economic products I can speak with more
confidence, that being my special department in our family or home
gardening, which, as physical discipline, I have always conducted
myself, with a minimum of professional aid.
My experience of a small garden leads me to give first place to salads.
A yard square of rich soil, well managed, will yield a handsome
and delicious weekly dish of salad nearly all the year round; and,
at the same rate, seven or eight square yards will supply a daily
dish—including lettuces, endives, radishes, spring onions, mustard,
and various kinds of cress, and fancy salads, all in a state of
freshness otherwise unattainable by the Londoner. My only difficulty
has arisen from irregularity of supply. From the small area allowed
for salads, I have been over-supplied in July, August, and September,
and reduced to in-door or frame-grown mustard and cress during the
winter. With the equable insular climate obtainable under the canvas,
this difficulty will be greatly diminished; and besides this, most of
the salads are improved by partial shade, lettuces and endives more
blanched and delicate than when exposed to scorching sun, radishes less
fibrous, mustard, cress, etc., milder in flavor and more succulent.
The multitude of savory kitchen herbs that are so sadly neglected
in English cookery (especially in the food of the town artisan and
clerk), all, with scarcely an exception, demand an equable climate and
protection from our destructive spring frosts. These occupy very little
space, less even than salads, and are wanted in such small quantities
at a time, and so frequently, that the hard-worked housewife commonly
neglects them altogether, rather than fetch them from the greengrocer’s
in their exorbitantly small pennyworths. If she could step into the
back yard, and gather her parsley, sage, thyme, winter savory, mint,
marjoram, bay leaf, rosemary, etc., the dinner would become far more
savory, and the demand for the alcoholic substitutes for relishing food
proportionably diminished.
My strongest anticipations, however, lie in the direction of common
fruits—apples, pears, cherries, plums of all kinds, peaches,
nectarines, gooseberries, currants, raspberries, strawberries, etc.
The most luxuriant growth of cherries, currants, gooseberries, and
raspberries I have ever seen in any part of the world that I have
visited, is where they might be least expected, viz., Norway; not the
South of Norway merely, but more particularly in the valleys that
slope from the 500 square miles of the perpetual ice desert of the
Justedal down to the Sognefjord, latitude 61° to 61½°, considerably to
the north of the northernmost of the Shetland Islands. The cherry and
currant trees are marvelous there.
In the garden of one of the farm stations (Sande) I counted 70 fine
bunches of red currants growing on six inches of one of the overladen
down-hanging stems of a currant bush. Cherries are served for dessert
by simply breaking off a small branch of the tree and bringing it to
the table—the fruit almost as many as the leaves.
This luxuriance I attribute to two causes. First, that in that part
of Norway the winter breaks up suddenly at about the beginning of
June, and not until then, when night frosts are no longer possible,
do the blossoms appear. It was on the 24th August that I counted
the 70 bunches of ripe currants. The second cause is the absence of
sparrows and other destructive small birds that devour our currants
for the seeds’ sake before they ripen, and our cherries immediately
on ripening. These are preceded by the bullfinches that feed on the
tender hearts of the buds of most of our fruit trees. Those who believe
the newspaper myths which represent such thick-billed birds eating
caterpillars, should make observations and experiments for themselves
as I have done.
In our canvas conservatories neither sparrows nor caterpillars, nor
wasps, or other fruit-stealers will penetrate, nor will the spring
frosts nip the blossoms that open out in April. All the conditions
for full bearing are there fulfilled, and the ripening season, though
not so intense, will be prolonged. We shall have an insular Jersey
climate in London, where the mean temperature is higher than in the
country around, and, if I am not quite deluded, we shall be able to
grow the choicest Jersey pears, those that best ripen by hanging on the
tree until the end of December, and fine peaches, which are commonly
destroyed by putting forth their blossoms so early. All the hundred and
one varieties of plums and damsons, greengages, etc., that can grow in
temperate climates will be similarly protected from the frosts that
kill their early blossoms, and the birds and the wasps that will not
give them time to ripen slowly.
I have little doubt that if my project is carried out, any London
householder, whether rich or poor, may indulge in delicious desserts of
rich fruit all grown on the sites of their own now dirty and desolate
back-yards; that if prizes be given for the most prolific branches of
cherry and plum trees, gooseberry and currant bushes, the gardens of
the Seven-dials and of classic St. Giles’s may carry off some of the
gold medals; and that, by judicious economy of space and proper pruning
of the trees, the canvas conservatories may be made not only to serve
as orchard houses, but also to grow the salads, kitchen herbs, and
green vegetables for cookery, under the fruit trees or close around
their stems.
Among the suitable vegetables, I may name a sort of perennial spinach
which yields a wonderful amount of produce on a small area. Four years
ago I took the house in which I now reside, and found the garden
overgrown with a weed that appeared like beet, the leaves being much
larger than ordinary spinach. I tried in vain to eradicate it, then
gave some leaves to my fowls. They ate them greedily. After this I
had some boiled, and found that the supposed weed is an excellent
spinach, which may be sown broadcast in thick patches, without any
interspaces, and cut down again and again all the year round, fresh
leaves springing up from the roots until the autumn, when it throws
up tall flowering stems, and yields an abundant crop of seeds. I have
some now, self-sown, that have survived the whole of the late severe
winter, while turnip-tops, cabbages, and everything else have perished.
I have sown the ordinary spinach seed in the usual manner in rows, and
comparing it with the self-sown dense patches of this intruder, find
the latter produces, square yard against square yard, six or eight
times as much of available eatable crop.
None of my friends who are amateur gardeners know this variety; but
a few days since, I called on Messrs. James Carter and Co., the
wholesale seedsmen of Holborn, and described it. They gave me a packet
of what they call “Perpetual spinach beet,” which, as may be seen by
comparison with the seeds of those I have here of my own growing, is
probably the same. Messrs. Carter and Co. tell me that the plant is
very little known, and the seed scarce from want of cultivation and
demand. I therefore step so far aside to describe and recommend it as
specially suited for obtaining large crops on small areas.[33]
I also recommend a mode of growing cabbages that I have found very
profitable, viz., to sow the seed broadcast in richly manured beds
or patches and leave the plants crowding together; cut them down
while very young, without destroying the centre bud; let them sprout
again and again. They thus yield a succession of crops, every leaf of
which is eatable. This, instead of transplanting and growing large
plants, which, however desirable for sale in the market, are far less
profitable for home use. Celery may be grown in like manner, and cut
down young and green for boiling.
Some collateral advantages may be fairly anticipated in cases where the
back-yard is fully enclosed by the canvas.
In the first place, the air coming into the house from the back will
be more or less filtered from the grimy irritant particles with which
our London atmosphere is loaded, besides obtaining the oxygen given off
by the growing plants, and the ozone which recent investigations have
shown to be produced where aromatic plants—such as kitchen herbs—are
growing. Lavender, which is very hardy, and spreads spontaneously,
might be grown for this purpose.
Back-doors might be left open for ventilation, without danger of
intrusion or of slamming by gusts of wind. The air thus admitted would
be tempered both in summer and winter. By wetting the canvas, which may
easily be done by means of a small garden engine, or hand syringe, the
exceptionally hot summer days that are so severely felt in London might
be moderated to a considerable extent. The air under the canvas being
cooler than that in front would enter from below, while the warmer air
would be pushed upwards and outwards to the front.
Although such conservatories may be erected, as already stated,
by artisans or other tenants of small houses, I do not advocate
dependence on this; but, on the contrary, regard them as more properly
constituting landlord’s fixtures, and recommend their erection by
owners of small house property in London and other large towns. A
workman who will pay a trifle extra for such a garden, is likely to be
a better and more permanent tenant than one who is content with the
slovenly squallor of ordinary back premises.
I base this opinion on some experience of holding small houses in the
outskirts of Birmingham (Talbot Street, Winson Green.) These have
small gardens, while most of those around have none. They are held by
weekly tenure, and, during eighteen years, I have not lost a week’s
rent from voids; the men who would otherwise shift their dwelling
when they change workshops, prefer to remain and walk some distance
rather than lose their little garden crops; and when obliged to leave,
have usually found me another tenant, a friend who has paid them a
small tenant-right premium for what is left in the garden, or for the
privilege of getting a house with such a garden.
A small garden is one of the best rivals to the fascinations of the
tap-room; the strongest argument in favor of my canvas conservatories,
and that which I reserve as the last, is that they are likely to become
the poor man’s drawing-room, where he may spend his summer evenings,
smoke his pipe, contemplate his growing plants, and show them in
rivalry to his friends, rather than slink away from an unattractive
home to seek the sensual excitements that ruin so many of our
industrious fellow-countrymen.
As above stated, I have not been able practically to test the filtering
capabilities of the canvas, owing to my residence out of town, but
since the above was written, _i.e._, on last Wednesday evening, I
visited the Houses of Parliament, where, as I had been told, the
ventilation arrangements include some devices for filtering the air by
cotton, wool or otherwise.
I was much interested on finding that the long experience and many
trials of Dr. Percy and his assistant engineer, Mr. Prim, have resulted
in the selection of the identical material which I have chosen, and
with which the above-described experiments have been made. A wall of
such canvas surrounds a lower region of the Houses, and all the air
that is destined to have the privilege of being breathed by British
legislators is passed through this vertical screen, for the purpose of
separating from it the sooty impurities that constitute the special
abomination of our metropolitan atmosphere, and that of our great
manufacturing towns. The quantity of sooty matter thus arrested is
shown by the fact that it is found necessary to take the screens down
once a week and wash them, the wash water coming away in a semi-inky
condition.
I anticipate that the conservatory filters will rapidly clog, and,
therefore, require washing. This may easily be done by means of a
jet from a hand-syringe directed from within outwards, especially if
the slope of the roof is considerable, which is to be recommended.
The filtering screen of the Houses of Parliament is made by sewing
the canvas edges together, to form a large continuous area, then
edging the borders of this with tape, and stretching it bodily on to
a stout frame. This method may be found preferable to that which I
proposed above, and cheaper than I have estimated, as only very light
intermediate cross-pieces would thus be required, merely to prevent
bagging, the parliamentary quartering above described being nine feet
apart instead of three. This would reduce the cost of timber to about
one half of the above estimate.[34] The perpendicular walls of a
conservatory, where such are required, may certainly be made thus, and
I think the roof also, if the slope is considerable. Or, if in demand,
the material may be made of greater width than the three feet.
So far, I have only mentioned back-yards; but, besides these, there
are many very melancholy front areas, called “gardens,” attached to
good houses in some of the once suburban, but now internal regions of
London, where the houses stand some distance back from the formerly
rural highway. These spaces might be cheaply enclosed with canvas,
and cultivated as kitchen gardens, orchard houses, flower gardens, or
ferneries, thus forming elegant, refreshing, and profitable vestibules
between the highway and the house-door, and also serve as luxurious
summer drawing-rooms. The only objection I foresee to these bright
enclosures will be their tendency to encourage the consumption of
tobacco.
_The Discussion which followed the reading of the preceding paper at
the Society of Arts._
A member asked if Mr. Williams had observed the effect of wind and rain
on this material?
Mr. W. P. B. Shepheard said he was interested in a large square in
London, and he had hoped to hear something about the cultivation of
flowers in such places. Last year, they tried the experiment with
several varieties of flower seeds, and they came up and bloomed well
in the open ground without any protection whatever. In most London
squares, the difficulty was to find anyone bold enough to try the
experiment at all, and nothing but experience would prove what flowers
would succeed and what would not. They were so successful last year
that several fine bouquets were gathered in July and August, and sent
to some of the gardening magazines, who expressed their astonishment
that such good results were possible in the circumstances. If flowers
would answer, there would, of course, be more encouragement to try
vegetables. One of the practical difficulties which occurred to him,
with regard to this plan, was that the screens would be somewhat
unsightly, and then again they might shrink, from alteration in the
temperature and getting wet and dry. He would repeat, however, that,
for a very small expense in seeds, a very good show of hardy annuals
and perennials might be obtained in July and August even in London.
Mr. C. Cooke said a flower-garden had recently been opened in Drury
Lane, on the site of an old churchyard, to which children were
admitted; and he wished a similar arrangement might be made in some
of the squares in crowded neighborhoods, such as Golden Square, and
especially in Lincoln’s Inn Fields. There were lots of children playing
about in the streets, and he wished the good example set by the
Templars might be followed.
Mr. Liggins, as an old member of the Royal Horticultural Society,
felt a great interest in this subject. Among his poorer neighbors in
the district of Kensington, cottage and window gardening had been
encouraged for some years past, prizes having been awarded to those
who were most successful, much to their gratification. This was a
novel idea, but he felt quite sure that it would enable those who
adopted it to obtain the crops which had been described. There were
many collateral advantages which it would bestow on the working classes
if largely followed by them, especially the one mentioned by Mr.
Williams, that those who devoted their spare time to the cultivation
of fruit and flowers would not be so open to the attractions of the
public-house. When traveling through the United States some years ago,
he was much struck with the difference in appearance of the houses in
districts where the Maine liquor law was in force, and soon learned to
distinguish where it was adopted by the clean, cheerful look of the
workmen’s dwellings, the neatness of the gardens, and the presence of
trees and flowers which, in other districts, were wanting. He was not
a teetotaler himself, and was not advocating such restrictions, but he
could not help noticing the contrast; and he felt sure that in all our
large towns great progress in civilization and morals would be effected
if such an attraction were offered to the working classes. He believed
there was so much intelligence and good sense among them, that if they
only knew what could be done in this way they would attempt it; and
when an Englishman attempted anything, he generally succeeded.
Mr. William Botly said they were much indebted to Mr. Williams for
having called attention to this important subject. He quite agreed
with the observations of the last speaker, for his own experience in
building cottages showed him that the addition of a piece of garden
ground had an excellent effect on the social, moral, and religious
welfare of the inmates. It kept them from the public-house, and the
children who were brought up to hoe and weed their parents’ gardens
turned out the most industrious laborers on his property. He had known
of instances where houses had been built with flat concrete roofs,
and covered in with glass, so as to form a conservatory, in which
vegetables and salads grow very well, and he believed the cost was
little, if any, more than ordinary slating.
The Chairman (Lord Alfred Churchill) in moving a vote of thanks to
Mr. Williams, said there could be no doubt that if his suggestion
were adopted it would lead to great economy, and have many other
attractions for the working classes. During the last few years they
had heard a good deal about floriculture in windows, and no doubt it
was an excellent proposal, but if they could add to this the growth
of vegetables it would have economical advantages also. The proposal
to erect temporary conservatories on the roofs of some of these small
houses was an admirable one. He saw no reason why you should not have
a peach tree growing against many a tall chimney; you would only
want a metal-lined tub filled with a good mold; the warmth of the
chimney would aid in promoting the growth of the tree, and it could
be protected from the smoke and frost by this canvas. One point he
should like to know was, whether the fabric would not become rotted
by the weather, and perhaps it might be protected by tanning, or some
chemical preparation. The effect of the canvas in maintaining an
equable temperature was a great consideration; the difference stated by
Mr. Williams, of about five degrees in winter, in many cases would be
just enough to save the life of a plant. Practical gardeners knew the
value of placing a covering over a peach tree in early spring to keep
off the frosts, and also to protect it from the attacks of birds. It
was also a curious fact that even a slip of wood or slate a few inches
wide, put on the top of a wall to which a fruit tree was nailed, acted
as a protection from frost. He trusted that Mr. Williams’ idea would
find favor among the working classes, and thought it was a subject
the Royal Horticultural Society might well take up and offer prizes
for. He hoped in a short time, when that Society had passed through a
crisis which was impending, it might emerge in a condition to devote
attention to this matter. It already offered prizes for small suburban
flower-shows, but had not yet turned its attention to the larger class
aimed at by Mr. Williams.
Mr. Botly said he had forgotten to mention that he had a friend, a very
excellent gardener, who always loosened his fruit trees from the wall
for about three weeks before the time of blooming. The consequence was,
they did not get so much heat from the wall, and the bloom was two or
three weeks later in forming. After the spring frosts, the trees were
again nailed up close, and he never failed in getting an excellent
crop, when his neighbors often had none.
Mr. Trewby wished to caution those who read the paper against using
what was commonly known as paperhangers’ canvas, because it was made
of two materials, hemp and jute, and if a piece of it were put into
water it would soon be nothing but a lot of strings, the jute being
all dissolved. It did very well for paper-hanging, but would be quite
unsuitable for this purpose.[35]
The vote of thanks having been passed—
Mr. Williams, in reply, said he had had a piece of this canvas
stretched on a frame exposed all the winter, and the only result was to
make it rather dirty. He stretched it as tightly as he could in putting
it on, but when it got wet it became still more tight, and gave a
little again on becoming dry. It bore the weight of the snow which had
fallen very well, and two or three spadefuls had been added to try it.
He had a note from Mr. Prim, saying that at the Houses of Parliament
the screens last about two sessions, being washed once a week, and the
destruction is due to the wringing. But there is really no occasion for
this, for if you syringe the stuff well from the inside, you make it
sufficiently clear to allow the air and light to pass through, and it
would probably last many years. He had tried the experiment of dipping
it in a very weak solution of tar, but this had the effect of matting
together the fine filaments, so that it did not act so effectually as
a strainer. It acted best when wet, because the fine particles of soot
adhered to it, and moist weather was just the time when the greatest
quantity of soot fell. It might be easily tried in London squares to
aid in the growth of flowers; he found that the cabbage plants which
were so protected throve remarkably well, and he had no doubt that
if flowers were planted and a screen put over them until they were
ready to bloom, it would be a great advantage. The action of a little
peat on the top of a wall to protect fruit trees is very simple, and
the explanation was afforded by the experiments of Dr. Wells on dew.
The frosts which did the greatest mischief, were due to radiation
from the ground on clear nights; and it would be found that if one
thermometer were placed in a garden under an umbrella, and another on
the open ground near it, the differences of temperature would be very
considerable; on cloudy nights there was very little difference. Last
night there was only a difference of 2°, but a few nights before it was
6°. The period of greatest cold might not probably be more than hour,
but it would be sufficient to do a great deal of mischief, and anything
which would check the radiation would have the required effect. In the
case of loosening the fruit trees from the wall there was, probably, a
double action; it prevented the tree being forced on by the warmth or
the wall in the daytime, and also avoided the chilling effect at night,
a rough wall being a good radiator, and sinking to a low temperature.
He did not think there was much danger to be apprehended from wind,
because the canvas being so open, the wind would pass freely through
it; but he had not seen it subjected to any violent gale.
SOLIDS, LIQUIDS, AND GASES.
The growth of accurate knowledge is continually narrowing, and
often obliterating, the broad lines of distinction that have been
drawn between different classes of things. I well remember when our
best naturalists regarded their “species” of plants and animals as
fundamental and inviolable institutions, separated by well-defined
boundaries that could not be crossed. Darwin has upset all this, and
now we cannot even draw a clear, sharp line between the animal and
vegetable kingdoms. The chemist is even crossing the boundary between
these and the mineral kingdom, by refuting the once positive dictum
that organic substances (_i.e._, the compounds ordinarily formed in the
course of vegetable or animal growth) cannot be produced directly from
dead matter by any chemical device. Many of such organic compounds are
now made in the laboratory from mineral materials.
We all know, broadly, what are the differences between solids, liquids,
and gases, and, until lately, they have been very positively described
as the three distinct states or modes of existence of matter. Mr.
Crookes suggests a fourth. I will not discuss this at present, but
merely consider the three old-established claimants to distinctive
existence.
A solid is usually defined as a body made up of particles which hold
together rigidly or immovably, in contradistinction to a fluid, of
which the particles move freely over each other. “Fluids” is the
general term including both gases and liquids, both being alike as
regards the mobility of their particles. At present, let us confine our
attention to liquids and solids.
The theoretical or perfect fluid which is imagined by the mathematician
as the basis of certain abstract reasonings has no real existence. He
assumes (and the assumption is legitimate and desirable, provided its
imaginary character is always remembered) that the supposed particles
move upon each other with perfect freedom, without any friction or
other impediment; but, as a matter of fact, all liquids exert some
amount of resistance to their own flowing; they are more or less
_viscous_, have more or less of that sluggishness in their obedience to
the law of finding their own level which we see so plainly displayed by
treacle or castor oil.
This viscosity, added to the friction of the liquid against the solid
on which it rests, or in which it is enclosed, may become, even in the
case of water, a formidable obstacle to its flow. Thus, if we make a
hole in the side of a tank at a depth of 16 feet below the surface,
the water will spout from that hole at the rate of 32 feet per second,
but if we connect with this hole a long horizontal pipe of the same
internal diameter as the hole, and then observe the flow from the
outlet of the pipe, we shall find its velocity visibly diminished,
and we shall be greatly deceived if we make arrangements for carrying
swift-flowing water thus to any great distances.
Three or four years ago an attempt was made to supersede the
water-carts of London by laying down on each side of the road a
horizontal pipe, perforated with a row of holes opening towards the
horse-way. The water was to be turned on, and from these holes it was
to jet out to the middle of the road from each side, and thus water it
all. I watched the experiment made near the Bank of England.
Instead of spouting across the road from all these holes, as it would
have done from any _one_ of them, it merely dribbled; the reason being
that, in order to supply them all, the water must run through the whole
of the long pipe with considerable velocity, and the viscosity and
friction to be overcome in doing this nearly exhausted the whole force
of water-head pressure. Many other similar blunders have been made by
those who have sought to convey water-power to a distance by means of a
pipe of such diameter as should demand a rapid flow through a long pipe.
The resistance which water offers to the stroke of the swimmer or the
pull of the rower is partly due to its viscosity, and partly to the
uplifting or displacement of some of the water. If it were perfectly
fluid, our movements within it, and those of fishes, etc., would be
curiously different; the whole face of this globe would be strangely
altered in many respects.
I will not now follow up this idea, but leave it as a suggestion for
the reader to work out for himself, by considering what would remain
undone upon the earth if water flowed perfectly, without any internal
resistance, or friction upon the earth’s surface.
The degrees of approach to perfect fluidity vary greatly with different
liquids.
Is there any such a thing as an absolute solid, or a body that has no
degree of fluidity, the particles or parts of which will admit of no
change of their relative positions, no movement upon each other without
fracture of the mass? This would constitute perfect _rigidity_, or the
opposite to _fluidity_.
Take a piece of copper or soft iron wire, about one eighth of an inch
in diameter, or thereabouts, and bend it backwards and forwards a few
times as rapidly as possible, but without breaking it; then, without
loss of time, feel the portion that has been bent. It is hot—painfully
so—if the experiment is smartly made. How may this be explained?
It is evident that in the act of bending there must have been a
displacement of the relative positions of the particles of the metal,
and the force demanded for the bending indicated their resistance
to this movement upon each other; or, in other words, that there
was friction between them, or something equivalent to such internal
friction, and thus the mechanical force exerted in the bending was
converted into heat-force.
Here, then, was fluidity, according to the above definition; not
perfect fluidity, but fluidity attended with resistance to flow, or
what we have agreed to call viscosity. But water also offers such
resistance to flow, or viscosity, therefore the difference between
iron or copper wire and liquid water as regards their fluidity is
only a difference of degree, and not of kind; the demarcation between
solids and liquids is not a broad, clearly-defined line, but a band
of blending shade, the depths of tint representing varying degrees of
viscosity.
Multitudes of examples may be cited illustrating the viscosity of
bodies that we usually regard as types of solidity, such, for example,
as the rocks forming the earth’s crust. In the “Black Country” of South
Staffordshire, which is undermined by the great ten-yard coal-seam,
cottages, chimney-shafts, and other buildings may be seen leaning over
most grotesquely, houses split down the middle by the subsidence or
inclination of one side, great hollows in fields or across roads that
were once flat, and a variety of other distortions, due to the gradual
sinking of the rock-strata that have been undermined by the colliery
workings. In some cases the rocks are split, but usually the subsidence
is a bending or flowing down of the rocks to fill up the vacuity, as
water fills a hollow, or “finds its own level.”
I have seen many cases of the downward curvature of the roof of a
coal-pit, and have been told that in some cases the surrounding
pressure causes the floor to curve upwards, but have not seen this.
Earthquakes afford another example. The so-called solid crust of the
earth is upheaved, and cast into positive billows that wave away on
all sides from the centre of disturbance. The earth-billows of the
great Lisbon earthquake of 1755 traveled to this country, and when they
reached Loch Lomond, were still of sufficient magnitude to raise and
lower its banks through a perpendicular range of two feet four inches.
It is quite possible, or, I may say, probable, that there are tides
of the earth as well as of the waters, and the subject has occupied
much attention and raised some discussion among mathematicians. If the
earth has a fluid centre, and only a comparatively thin crust, as some
suppose, there must be such tides, produced by the gravitation of the
moon and sun.
Ice presents some interesting results of this viscosity. At a certain
height, varying with latitude, aspect, etc., we reach the “snow line”
of mountain slopes, above which the snow of winter remains unmelted
during summer, and, in most cases, goes on accumulating. It soon loses
its flocculent, flaky character, and becomes coherent, clear blue ice
by the pressure of its own weight.
A rather complex theory has been propounded to explain this change—the
theory of _regelation_—_i.e._, re-freezing; a theory which assumes
that the pressure first thaws a film of ice at the surface of contact,
and that presently this re-freezes, and thus effects a healing or
general solidification. Faraday found that two pieces of ice with
moistened surfaces united if pressed together when at just about
the temperature of freezing, but not if much colder. Tyndall has
further illustrated this by taking fragments of ice and squeezing
them in a mould, whereby they became a clear, transparent ball, or
cake. Schoolboys did the like long before, when snowballing with snow
at about the thawing point. Such snow, as we all remember, became
converted into stony lumps when firmly pressed together. We also
remember that in much colder weather no such cohesion occurred, but our
snowballs remained powdery in spite of all our squeezing.
I am a sceptic as regards this theory of regelation. I believe that
the true explanation is much simpler; that the crystals of snow or
fragments of ice in these experiments are simply welded, as the smith
unites two pieces of iron, by merely pressing them together when they
are near their melting point. Other metals and other fusible substances
may be similarly welded, provided they soften or become sufficiently
viscous before fusing.
Platinum is a good example of this. It is infusible in ordinary
furnaces, but becomes pasty before melting, and therefore, one method
adopted in the manufacture of platinum ingots or bars from the ore,
is to precipitate a sort of platinum snow (spongy platinum) from its
solution in acid, and then compress this metallic snow in red-hot steel
moulds by means of pistons driven with great force. The flocculent
metal thus becomes a solid, coherent mass, just as the flocculent ice
became coherent ice in Tyndall’s experiment or in making hard snowballs.
Wax, pitch, resin, and all other solid that fuse _gradually_, cohere,
are weldable, or, in very plain language, “stick together,” when near
their fusing point.
I have made the following experiment to prove that when this so-called
regelation of snow or ice-fragments occurs, the ice is viscous or
plastic, like wax or pitch. A strong iron squirt, with a cylindrical
bore of half an inch in diameter, is fitted with an iron piston. This
piston is driven forth by a screw working in a collar at one end of the
squirt. Into the other end is screwed a brass nozzle with an aperature
about one twentieth of an inch diameter, tapering or opening inwards
gradually to the half-inch bore.
Into this bore I place snow or fragments of ice, then, holding the body
of the squirt firmly in a vice, I work the lever of the screw, and thus
drive forward the piston and crush down the snow or ice-fragments,
which presently become coherent and form a half-inch solid cylinder of
clear ice. Applying still more pressure, this cylinder is forced like
a liquid through the small orifice of the nozzle of the squirt, and
it jets or spouts out as a thin stick of ice like vermicelli, or the
“leads” of ever-pointed pencils, for the moulding of which the squirt
was originally constructed.
I find that ice at 32° can thus be squirted more easily than beeswax
of the same temperature, and such being the case, I see no reason
for imagining any complex operation of regelation in the case of
the ice, but merely regard the adhesion of two pieces of ice when
pressed together as similar to the sticking together of two pieces of
cobblers’-wax, or softened sealing-wax, or beeswax, or the welding of
iron or glass when heated to their welding temperatures, _i.e._, to a
certain degree of incipient fluidity or viscosity.
If a leaden bullet be cut in half, and the two fresh-cut faces pressed
forcibly together, they cohere at ordinary atmospheric temperatures,
but we have no occasion for a regelation theory here. The viscosity
of the lead accounts for all. At Woolwich Arsenal there is a monster
squirt, similar to my little one. This is charged with lead, and, by
means of hydraulic pressure, the lead is squired out of the nozzle as a
cylindrical jet of any required diameter. This jet or stick of lead is
the material of which the elongated cylindrical rifle bullets are now
made.
But returning to the point at which we started, on the subject of ice,
viz., its Alpine accumulation above the snow-line. If the snow-fall
there exceeds the amount that is thawed and evaporated, it must either
go on growing upward until it reaches the highest atmospheric region
from which it falls, or is formed, or it must descend somehow.
If ice can be squirted through a syringe by mere hand-pressure, we are
justified in expecting that it would be forced down a hill slope, or
through a gully, or across a plain, by the pressure of its own weight
when the accumulation is great. Such is the case, and thus are glaciers
formed.
They are, strictly speaking, rivers or torrents of ice; they flow as
liquid water does, and down the same channels as would carry the liquid
surface drainage of the hills, were rain to take the place of snow.
Like rivers, they flow with varying speed, according to the slope; like
rivers, their current is more rapid in the middle than the sides; like
rivers, they exert their greatest tearing force when squeezed narrow
through gullies; and, like rivers, they spread out into lakes when they
come upon an open basin-like valley, with narrow outlet.
The Justedalsbrae of Norway is a great ice-lake of this character,
covering a surface of about 500 square miles, and pouring down its
ice-torrents on every side, wherever there is a notch or valley
descending from the table-land it covers. The rate of flow of such
downpouring glaciers varies from two or three inches to as many feet
per day, and they present magnificent examples of the actual fluidity
or viscosity of an apparently solid mass. This viscosity has been
disputed, and attempts have been made to otherwise explain the motion
of glaciers; but while it is possible that it may be assisted by
varying expansion and contraction, the downflow due to viscosity is now
recognized as unquestionably the main factor of glacier motion.
Cascades of ice may be sometimes seen. In the course of my first visit
to Norway, I wandered alone over a very desolate mountain region
towards the head of the Justedal, and unexpectedly came upon a gloomy
lake, the Styggevand, which lies at the foot of a precipice-boundary
of the great ice-field above named. Here, the ice having no sloping
valley-trough by which to descend, poured over the edge of the
precipice as a great overhanging sheet or cornice, which bent down
as it was pushed forward, and presented on the convex side of the
sheet some fine blue cracks, or “crevasses” as they are called. These
gradually widened and deepened, until the overhanging mass broke off
and fell into the lake, on the surface of which I saw the result, in
the form of several floating icebergs that had previously fallen.
Something like this, on a small scale, may be seen at home on the edge
of a house roof, on which there has been an accumulation of snow; but,
in this case, it is rather sliding than flowing that has made the
cornice; but its _down-bending_ is a result of viscosity.
These and a multitude of other facts that might be stated, many of
which will occur to the reader, prove clearly enough that the solid and
liquid states of matter are not distinctly and broadly separable, but
are connected by an intermediate condition of viscosity.
We now come to the question whether there is any similar continuity
between liquids and gases. Ordinary experience decidedly suggests a
negative answer. We can point to nothing within easy reach that has the
properties of a liquid and gaseous half-and-half; that stands between
gases and liquids as pitch and treacle stand between solids and liquids.
Some, perhaps, may suggest that cloud-matter—London fog, for
example—is in such an intermediate state. This, however, is not the
case. White country fog, ordinary clouds, or the so-called “steam”
that is seen assuming cloud forms as it issues from the spout of a
tea-kettle or funnel of a locomotive, consists of minute particles of
water suspended in air, as solid particles of dust are also suspended.
It has been called “vesicular vapor,” on the supposition that it
has the form of minute vesicles, like soap-bubbles on a very small
scale, but this hypothesis remains unproven. London fog consists of
similar particles, varnished with a delicate film of coal-tar, and
intersprinkled with particles of soot.
In order to clearly comprehend the above-stated question, we must
define the difference between liquids and gases. In the first place,
they are both fluids, as already agreed. What, then, is the essential
difference between liquid fluidity and gaseous fluidity? The expert
in molecular mathematics, discoursing to his kinematical brethren,
would produce a tremendous reply to this question. He would describe
the oscillations, gyrations, collisions, mean free paths, and mutual
obstructions of atoms and molecules, and, by the aid of a maddening
array of symbols, arrive at the conclusion that gases, unless
restrained, expand of their own accord, while liquids retain definite
limits or dimensions.
The matter-of-fact experimentalist demonstrates the same by methods
that are easily understood by anybody. I shall, therefore, both for my
own sake and my readers’, describe some of the latter.
In the first place, we all see plainly that liquids have a surface,
_i.e._, a well-defined boundary, and also that gases, unless enclosed,
have not. But as this may be due to the invisibility of the gas, we
must question it further. The air we breathe may be taken as a type
of gases, as water may of liquids. It has weight, as we may prove by
weighing a bottle full of air, then pumping out the contents, weighing
the empty bottle, and noting the difference.
Having weight, it presses towards the earth, and is squeezed by all
that rests above it; thus the air around us is constrained air. It is
very compressible, and is accordingly compressed by the weight of all
the air above it.
This being understood, let us take a bottle full of water and another
full of air, and carry them both to the summit of Mont Blanc, or to a
similar height in a balloon. We shall then have left nearly half of the
atmosphere below, and thus both liquid and gas will be under little
more than half of the ordinary pressure. What will happen if we uncork
them both? The liquid will still display its definite surface, and
remain in the bottle, but not so the gas. It will overflow upwards,
downwards, or sideways, no matter how the bottle is held, and if we
had tied an empty bladder over the neck before uncorking, we should
find this overflow or expansion of the gas exactly proportionate to
the removal of pressure, provided the temperature remained unaltered.
Thus, at just half the pressure under which a pint bottle was corked,
the air would measure exactly one quart, at one-eighth of the pressure
one gallon, and so on.
We cannot get high enough for the latter expansion, but can easily
imitate the effect of further elevation by means of an air-pump. Thus,
we may put one cubic inch of air into a bladder of 100 cubic inches
capacity, then place this under the receiver of an air-pump, and reduce
the pressure outside the bladder to 1/100th of its original amount.
With such atmospheric surrounding, the one cubic inch of air will plump
out the flaccid bladder, and completely fill it. The pumpability of the
air from the receiver shows that it goes on overflowing from it into
the piston of the pump as fast as its own elastic pressure on itself is
diminished.
Numberless other experiments may be made, all proving that all
gases are composed of matter which is not merely incohesive, but is
energetically self-repulsive; so much so, that it can only be retained
within any bounds whatever by means of some external pressure or
constraint. For aught we know _experimentally_, the gaseous contents
of one of Mr. Glaisher’s baloons would outstretch itself sufficiently
to occupy the whole sphere of space that is spanned by the earth’s
orbit, provided that space were perfectly vacuous, and the baloon were
burst in the midst of it, the temperature of the expanding gas being
maintained.
Here, then, in this self-repulsiveness, instead of self-cohesion, this
absence of self-imposed boundary or dimensions, we have a very broad
and well-marked distinction between gases and liquids, so broad that
there seems no bridge that can possibly cross it. This was believed to
be the case until recently. Such a bridge has, however, been built, and
rendered visible, by the experimental researches of Dr. Andrews; but
further explanation is required to render this generally intelligible.
Until quite lately it was customary to divide gases into two
classes—“permanent gases” and “condensable gases,” or “vapors.”
Gaseous water or steam was usually described as typical of the latter;
oxygen, hydrogen, or nitrogen of the former. Earlier than this, many
other gases were included in the permanent list; but Faraday made a
serious inroad upon this classification when he liquefied chlorine
by cooling and compressing it. Long after this, the gaseous elements
of water, and the chief constituents of air, oxygen, hydrogen, and
nitrogen, resisted all efforts to condense them; but now they have
succumbed to great pressure and extreme cooling.
We thus arrive at a very broad generalization, viz., that all gases are
physically similar to steam (I mean, of course, “dry steam,” _i.e._,
true invisible steam, and not the cloudy matter to which the name of
steam is popularly given), that they are all formed by raising liquids
above their boiling point, just as steam is formed when we boil water
and maintain the steam above the boiling-point of the water.
But some liquids boil at temperatures far below that at which others
freeze; liquid chlorine boils at a temperature below that of freezing
water, and liquid carbonic acid below even that of freezing mercury,
and liquid hydrogen far lower still. These are cases of boiling,
nevertheless, though it seems a paradox according to the ideas we
commonly attach to this word. But such ideas are based on our common
experience of the properties of our commonest of liquids, viz., water.
When water boils under the conditions of our ordinary experience, the
passage from the liquid to the gaseous state is a sudden leap, with
no intermediate state of existence that we are able to perceive; and
the conditions upon which water is converted into steam—the liquid
into the gas—while both are at the bottom of our atmospheric ocean,
are such as to render an intermediate condition rationally, as well as
practically, impossible.
We find that the expansive energy by which the steam is enabled to
resist atmospheric pressure is conferred upon it by its taking into
itself, and utilizing for its expansive efforts a large amount of
calorific energy. When any given quantity of water is converted into
steam, under ordinary circumstances, its bulk _suddenly_ becomes
above 1700 times greater—a cubic inch of water forms about a cubic
foot of steam, and nearly 1000 degrees of heat (966·6) disappears
_as temperature_. Otherwise stated, we must give to the cubic inch
of water at 212° as much heat as would raise it to a temperature of
212 plus 966·6, or 1,178·6°, if it remained liquid. This is about
the temperature of the glowing coals of a common fire; but the steam
that has thus taken enough heat to make the water red-hot is still at
212°—no _hotter_ than the water was while boiling.
This heat, which thus ceases to exhibit itself as _temperature_,
is otherwise occupied. Its energy is partly devoted to the work of
increasing the bulk of the water to the above-named extent, and
partly in conferring on the steam its gaseous specialty—that is,
in overcoming liquid cohesion, and substituting for it the opposite
property of internal repulsive energy which is characteristic of gases.
My reasons for thus defining and separating these two functions of the
so-called “latent” heat will be seen when we come to the philosophy of
the interesting researches of Dr. Andrews.
As already explained, all gases are now proved to be analogous to
steam, they are matter expanded and rendered self-repulsive by heat.
All _elementary_ matter may exist in either of the three forms—solid,
liquid, or gas, according to the amount of heat and pressure to which
it is subjected. I limit this wide generalization to _elementary_
substances for the following reasons:
Many compounds are made up of elements so feebly held together
that they become “dissociated” when heated to a temperature below
their boiling-point; or, their condition maybe otherwise defined by
stating that the bonds of chemical energy, which hold their elements
together, are weaker than the cohesion which binds and holds them in
the condition of solid or liquid, and are more easily broken by the
expansive energy of heat.
To illustrate this, let us take two common and well-known oils—olive
oil and turpentine. The first belongs to the class of “fixed oils,” and
second to the “volatile oils.” If we apply heat to liquid turpentine,
it boils, passes into the state of gaseous turpentine, which is easily
condensible by cooling it. If the liquid result of this condensation
is examined, we find it to be turpentine as before. Not so with the
olive oil. Just as this reaches its boiling point, the heat, which
would otherwise convert it into olive-oil vapor, begins to dissociate
its constituents, and if the temperature be raised a little higher, we
obtain some gases, but these are the products of decomposition, not
gaseous olive oil. This is called “destructive” distillation.
In olive oil, the boiling-point and dissociation point are near to each
other. In the case of glycerine, these points so nearly approximate
that, although we cannot distil it unbroken under ordinary atmospheric
pressure, we may do so if some of this pressure is removed. Under
such diminished pressure, the boiling-point is brought down below the
dissociation point, and condensible glycerine gas comes over without
decomposition.
Sugar affords a very interesting example of dissociation, commencing
far below the boiling-point, and going on gradually and visibly, with
increasing rapidity as the temperature is raised. Put some white sugar
into a spoon, and heat the spoon gradually over the smokeless gas-flame
or spirit-lamp. At first the sugar melts, then becomes yellow (barley
sugar); this color deepens to orange, then red, then chestnut-brown,
then dark brown, then nearly black (caramel), then quite black, and
finally it becomes a mere cinder. Sugar is composed of carbon and
water; the heat dissociates this compound, separates the water,
which passes off as vapor, and leaves the carbon behind. The gradual
deepening of the color indicates the gradual carbonization, which is
completed when only the dry insoluble cinder remains. An appearance of
boiling is seen, but this is the boiling of the dissociated water, not
of the sugar.
The dissociation temperature of water is far above its boiling-point.
It is 5072° Fahr., under conditions corresponding to those which
make its boiling-point 212°. If we examine the variations of the
boiling-point of water, as the atmospheric pressure on its surface
varies, some curious results follow. To do this the reader must endure
some figures. They are extremely simple, and perfectly intelligible,
but demand just a little attention.
Following are three columns of figures. The first represents
atmospheres of pressure—_i.e._, taking our atmospheric pressure when
it supports 30 inches of mercury in the barometer tube as a unit, that
pressure is doubled, trebled, etc., up to twenty times in the first
column. The second column states the temperature at which water boils
when under the different pressures thus indicated. The third column,
which is the subject for special study just now, shows how much we
must rise the temperature of the water in order to make it boil as we
go on adding atmospheres of pressure; or, in other words, the increase
of temperature due to each increase of one atmosphere of pressure. The
figures are founded on the experiments of Regnault.
Pressure in Temperature, F. Rise of Temperature
Atmospheres ° for each additional
Atmosphere
1 212
2 249·5 37·5
3 273·3 23·8
4 291·2 17·9
5 306·0 14·8
6 318·2 12·2
7 329·6 11·4
8 339·5 9·9
9 348·4 8·9
10 356·6 8·2
11 364·2 7·6
12 371·1 6·9
13 377·8 6·7
14 384·0 6·2
15 390·0 6·0
16 395·4 5·4
17 400·8 5·4
18 405·9 5·1
19 410·8 4·9
20 415·4 4·6
It may be seen from the above that, with the exception of one
irregularity, there is a continual diminution of the additional
temperature which is required to overcome an additional atmosphere of
pressure, and if this goes on as the pressure and temperatures advance,
we may ultimately reach a curious condition—a temperature at which
additional pressure will demand no additional temperature to maintain
the gaseous state; or, in other words, a temperature may be reached at
which no amount of pressure can condense steam into water, or at which
the gaseous and liquid states merge or become indifferent.
But we must not push this mere numerical reasoning too far, seeing
that it is quite possible to be continually approaching a given point,
without ever reaching it, as when we go on continually halving the
remaining distance. The figures in the above do not appear to follow
according to such a law—nor, indeed, any other regularity. This
probably arises from experimental error, as there are discrepancies
in the results of different investigators. They all agree, however,
in the broad fact of the gradation above stated. Dulong and Arago,
who directed the experiments of the French Government Commission for
investigating this subject, state the pressure at 20 atmospheres to
be 418·4, at 21 = 422·9, at 22 = 427·3, at 23 = 431·4, and at 24
atmospheres, their highest _experimental_ limit, 435·5, thus reducing
the rise of temperature between the 23d and 24th atmospheres to 4·1.
If we could go on heating water in a transparent vessel until
this difference became a vanishing quantity, we should probably
recognize a visible physical change coincident with this cessation of
condensibility by pressure; but this is not possible, as glass would
become red-hot and softened, and thus incapable of bearing the great
pressure demanded. Besides this, glass is soluble in water at these
high temperatures.
If, however, we can find some liquid with a lower boiling-point, we may
go on piling atmosphere upon atmosphere of elastic expansive pressure,
as the temperature is raised, without reaching an unmanageable degree
of heat. Liquid carbonic acid, which, under a single atmosphere of
pressure, boils at 112° below the zero of our thermometer, may thus be
raised to a temperature having the same relation to its boiling-point
that a red-heat has to that of water, and may be still confined within
a glass vessel, provided the walls of the vessel are sufficiently thick
to bear the strain of the elastic outstriving pressure. In spite of its
brittleness glass is capable of bearing an enormous strain _steadily
applied_, as may be proved by trying to break even a mere thread of
glass by direct pull.
Dr. Andrews thus treated carbonic acid, and the experiment, as I have
witnessed its repetition, is very curious. A liquid occupies the lower
part of a very strong glass tube, which appears empty above. But this
apparent void is occupied by invisible carbonic acid gas, evolved by
the previous boiling of the liquid carbonic acid below. We start at
a low temperature—say 40° Fahr. Then the temperature is raised; the
liquid boils until it has given off sufficient gas or vapor to exert
the full expansive pressure or tension due to that temperature. This
pressure stops the boiling, and again the surface of the liquid is
becalmed.
This is repeated at a higher temperature, and thus continued until we
approach nearly to 88° Fahr., when the surface of the liquid loses
some of its sharp outline. Then 88° is reached, and the boundary
between liquid and gas vanishes; liquid and gas have blended into one
mysterious intermediate fluid; an indefinite fluctuating something
is there filling the whole of the tube—an etherealized liquid or a
visible gas. Hold a red-hot poker between your eye and the light; you
will see an upflowing wavy movement of what appears like liquid air.
The appearance of the hybrid fluid in the tube resembles this, but is
sensibly denser, and evidently stands between the liquid and gaseous
states of matter, as pitch or treacle stands between solid and liquid.
The temperature at which this occurs has been named by Dr. Andrews
the “_critical temperature_”; here the gaseous and liquid states are
“_continuous_,” and it is probable that all other substances capable of
existing in both states have their own particular critical temperatures.
Having thus stated the facts in popular outline, I shall conclude the
subject by indulging in some speculations of my own on the philosophy
of these general facts or natural laws, and on some of their possible
consequences.
As already stated, the conversion of water into steam under ordinary
atmospheric pressure demands 966·6° of heat over and above that which
does the work of raising the water to 212°, or, otherwise stated, as
much heat is at work in a given weight of steam at 212°, as would raise
the same quantity of water to 1178·6° if it remained liquid.
James Watt concluded from his experiments that a given weight of
steam, whatever may be its density, or, in other words, under whatever
pressure it may exist, contains the same quantity of heat. According
to this, if we reduced the pressure sufficiently to bring down the
boiling-point to 112°, instead of 212°, the latent heat of the steam
thus formed would be 1066·6° instead of 966·6°, or if, on the other
hand, we placed it under sufficient pressure to raise the boiling-point
to 312°, the latent heat of the steam would be reduced to 866·6°,
_i.e._, only 866·6° more would be required to convert the water into
steam. If the boiling-point were 412°, as it is between 19 and 20
atmospheres of pressure, only 766·6° more heat would be required, and
so on, till we reached a pressure which raised the boiling-point to
1178·6°; the water would then become steam without further heating,
_i.e._, the critical point would be reached, and thus, if Watt is
right, we can easily determine, theoretically, the critical temperature
of water.[36]
Mr. Perkins, who made some remarkable experiments upon very high
pressure steam many years ago, and exhibited a steam gun at the
Adelaide Gallery, stated that red-hot water does not boil; that if the
generator be sufficiently strong to stand a pressure of 60,000 lbs.
load on the safety-valve, the water may be made to exert a pressure of
56,000 lbs. on the square inch at a cherry-red heat without boiling.
He made a number of rather dangerous experiments in thus raising water
to a red-heat, and his assertion that red-hot water does not boil is
curious when viewed in connection with Dr. Andrews’ experiments.
I cannot tell how he arrived at this conclusion, having been unable
to obtain the original record of his experiments, and only quote the
above second hand. It is worthy of remark that the temperature he names
is about 1170°, or that which, if Watt is right, must be the critical
temperature of the water. Perkins’ red-hot water would not boil, being
then in the intermediate condition.
So far, we have a nice little theory, which not only shows how
the critical state of water must be reached, but also its precise
temperature; but all this is based on the assumption that Watt made no
mistake.
Unfortunately for the simplicity of this theory, Regnault states
that _his_ experiments contradict those of Watt, and prove that the
latent heat of steam does not diminish just in the same degree as
the boiling-point is raised, but that instead of this the diminution
of the latent heat progresses 30½ per cent more slowly than the rise
of temperature, so that, instead of the latent heat of steam between
boiling-points of 212° and 312° falling from 966·6° to 866·6° it
would only fall to 895·1° or 69·5° of latent heat for every 100° of
temperature.
If this is correct, the temperature at which the latent heat of
steam is reduced to zero is much higher than 1178·6°, and is, in
fact, a continually receding quantity never absolutely reached; but
I am not prepared to accept these figures of Regnault as implicitly
as is now done in text-books (I was nearly saying “as is now the
fashion”), seeing that they are not the actual figures obtained by his
experiments, but those of his “empirical formulæ” based upon them.
His actual experimental figures are very irregular; thus, between
steam temperature of 171·6° and 183·2° a difference of 11·6°, the
experimental difference in the latent heat came out as 4·7°; between
steam temperature of 183·2° and 194·8°, or 11·6° again, the latent heat
difference is tabulated as 8·0°.
Regnault’s experiments were not carried to very high temperatures and
pressures, and indicate that as these advance the deviation from Watt’s
law diminishes, and may finally vanish at about 1500° or 1600°, where
the latent heat would reach zero, and there, according to the above,
the critical temperature would be reached. Any additional heat applied
after this will have but one function to perform, viz., the ordinary
work of increasing the bulk of the heated body without doing anything
further in the way of conferring upon it any new self-repulsive
properties.
Our notions of solids, liquids, and gases are derived from our
experiences of the state of matter here upon this earth. Could we be
removed to another planet, they would be curiously changed. On Mercury
water would rank as one of the condensible gases; on Mars, as a fusible
solid; but what on Jupiter?
Recent observations justify us in regarding this as a miniature sun,
with an external envelope of cloudy matter, apparently of partially
condensed water, but red-hot, or probably still hotter within. His
vaporous atmosphere is evidently of enormous depth, and the force of
gravitation being on his visible outer surface two and a half times
greater than that on our earth’s surface, the atmospheric pressure in
descending below this visible surface must soon reach that at which the
vapor of water would be brought to its critical condition. Therefore we
may infer that the oceans of Jupiter are neither of frozen liquid nor
gaseous water, but are oceans or atmospheres of critical water. If any
fish-birds swim or fly therein they must be very critically organized.
As the whole mass of Jupiter is three hundred times greater than
that of the earth, and its compressing energy towards the centre
proportional to this, its materials, if similar to those of the earth
and no hotter, would be considerably more dense, and the whole planet
would have a higher specific gravity; but we know by the movement of
its satellites that, instead of this, its specific gravity is less than
a fourth of that of the earth. This justifies the conclusion that it
is intensely hot, for even hydrogen, if cold, would become denser than
Jupiter under such pressure.
As all elementary substances may exist as solids, liquids, or gases, or
critically, according to the conditions of temperature and pressure,
I am justified in hypothetically concluding that Jupiter is neither a
solid, a liquid, nor a gaseous planet, _but a critical planet_, or an
orb composed internally of dissociated elements in the critical state,
and surrounded by a dense atmosphere of their vapors, and those of some
of their compounds, such as water. The same reasoning applies to Saturn
and the other large and rarefied planets.
The critical temperature of the dissociated elements of the sun is
probably reached at the base of the photosphere, or that region
revealed to us by the sun-spots. When I wrote “The Fuel of the Sun,”
thirteen or fourteen years ago, I suggested, on the above grounds,
the then heretical idea of the red-heat of Jupiter, Saturn, Uranus,
and Neptune, and showed that all such compounds as water must be
dissociated at the base of the sun’s atmosphere; but being then
unacquainted with the existence of this critical state of matter, I
supposed the dissociated elements to exist as gases with a small solid
nucleus or kernel in the centre.
Applying now the researches of Dr. Andrews to the conditions of
solar existence, as I formerly applied the dissociation researches
of Deville, I conclude that the sun has no nucleus, either solid,
liquid, or gaseous, but is composed of dissociated matter in the
critical state, surrounded, first, by a flaming envelope due to the
re-combination of the dissociated matter, and outside of this another
envelope of vapors due to this combination.
MURCHISON AND BABBAGE.
The curious contrast of character presented by these two eminent men,
and the very different course of their lives, conveys a striking
lesson to all those superficial thinkers and unthinking talkers who
make sweeping generalizations concerning human character; who assume
as a matter of course that any man who writes poetry must be merely a
dreamer of day-dreams, incapable of transacting any practical daily
business, and not at all reliable in money matters; whose eyes are
always “in a fine frenzy rolling”; that he is, in short, a sort of
amiable, harmless lunatic. All actors, according to such people, are
dissipated spendthrifts; and if Sims Reeves, or any other public
performer, is prevented by delicate larynx or other indisposition from
appearing, they look knowing, shrug their shoulders, wink wisely, and
assume, without the faintest shadow of evidence, that he is drunk.
In like manner they set up a typical philosopher of their own
manufacture, and attribute his imaginary character to all who devote
themselves to science. Their philosopher is a musty, dried-up,
absent-minded pedant, whose ordinary conversation is conducted in
words of seven syllables, who is always lost in profound abstractions;
takes no interest in common things; regards music, dancing,
play-acting, poetry, and every cheerful pursuit as frivolous and
contemptible—a creature who never makes a joke, seldom laughs, and who
in matters of business is even more incapable than the poet.
The singular contrast of character presented by Babbage and Murchison
affords at once a most complete refutation of such generalizations.
Here were two men, both philosophers, one the very type of amiability,
suavity, and all conceivable polish, the very perfection of a courtier,
but differing from the vulgar courtier of the Court in this respect,
that his high-toned courtesy was not bestowed upon kings only, but also
upon all his human brethren, and with especial gracefulness upon those
whose rank was below his own.
I doubt whether there is any man now living, or has lived during this
generation, that could equal Sir Roderick Murchison in the art of
distributing showers of compliments upon a large number of different
people in succession, and making each recipient delightfully satisfied
with himself. In his position as Chairman to the Geological Section of
the British Association, he did this with marvelous tact, without the
least fulsomeness or repetition, or any display of patronizing. Every
man who read a paper before that section was better than ever satisfied
with the great merits and vast importance of his communication, after
hearing the Chairman’s comments upon it. None but a most detestably
strong-minded and logical brute could resist the insinuating flattery
of Sir Roderick.
How different was poor Babbage! Who that attends any sort of scientific
gatherings has not seen Sir Roderick? but who in the world, excepting
the organ-grinders and the police magistrate has ever seen Babbage, or
even his portrait? What a contrast between the seclusion and the public
existence; between the hedgehog bristles and the velvet softness, of
the one and the other!
Those who were on intimate terms with Babbage (I have never met
or heard of such a person) could probably tell us that all his
irritability and roughness were outside, and that, in the absence
of organ-grinders, he was a kind and amiable gentleman; but, even
admitting this, the contrast between the two philosophers is as great
as could well be found between any two men following the most widely
divergent studies or professions.
Those who would reply that mathematics and geology are such different
studies have only to go a little further back on the death-roll, and
they will find the name of De Morgan, a pure mathematician, like
Babbage. He was a man of exuberant fun and humor, and so far from
hating music of either a humble or pretentious character, was a highly
accomplished musician, both theoretical and practical, and if we are to
believe confidential communications, one of his favorite instruments
was the penny whistle, on which he was a most original and peculiar
performer.
I had not intended to reprint the above, which was written just after
the death of Murchison and Babbage, but the comments that have recently
followed the death of Darwin induce me to do so.
Many have expressed their surprise at the unanimous expressions of
Darwin’s friends concerning the geniality of his disposition, his
gentleness, cheerfulness; his _genuine_ humility and simplicity of
character.
A third type of character is here presented, and that which corresponds
most correctly with the true ideal of a modern philosopher, also
represented by that great master of experimental science, Faraday. In
both of these there was the full measure of Murchison’s amiability, but
without the courtly polish of the ex-soldier. Philosophic meditation
and close application to original research may, and often does, induce
a certain degree of shyness due to a consciousness of the social
disqualification which arises from that inability to fulfil all the
demands for small attentions which constitute conventional politeness;
a disability due to habits of consecutive thought and mental
abstraction.
A sensitive and amiable man would suffer much pain on finding that he
had neglected to supply the small wants of the lady sitting next to
him at a dinner party, and would withdraw himself from the risk of
repeating such unwitting rudeness. This holding back from ordinary
society, though really due to a conscientious sense of social duty and
tender regard for the feelings of others, is too often referred to a
churlish unsociality or arrogant assumption of superiority.
If Newton really did mistake the lady’s finger for a tobacco-stopper,
depend upon it the pain he suffered was far more acute than that
which he inflicted, and was suffered over and over again whenever the
incident was recollected.
ATMOSPHERE _versus_ ETHER.
One of the most remarkable meteors of which we have a reliable record
appeared on February 6, 1818. Several accounts of it were published,
the fullest being that in _The Gentleman’s Magazine_ of the time. (I
may here add, parenthetically, that one reason why I have especial
pleasure in writing these notes is that they contribute something
towards the restoration of the ancient status of this magazine, which
was at one time the only English serial that ventured upon any notable
degree of exposition of _popular_ science.)
Upon the data supplied by this account, Mr. Joule has calculated the
height of the meteor to have been 61 miles above the surface of the
earth, and he states that “this meteor is one of the few that have been
seen in the daytime, and is also interesting as having been one of the
first whose observation afforded materials for the estimation of its
altitude.” It was seen in the neighborhood of Cambridge at 2 P.M.,
also at Swaffham in Norfolk, and at Middleton Cheney near Banbury.
The distance between this and Cambridge is sufficient to afford a
measurement of its height, provided its position above the horizon at
both places was determined with tolerable accuracy.
According to the orthodox text-books, the atmosphere of this earth
terminates at a height of about 45 or 50 miles, or, if not absolutely
ended there, it ceases to be of appreciable density anywhere above this
elevation.
But here we have a fact which flatly contradicts the calculation. At
61 miles above the earth’s surface there must be atmospheric matter of
sufficient density to offer to the passage of this meteor through it an
amount of resistance which produced an intense white heat, visible by
its luminosity in broad daylight.
In the above-quoted paper, read by Mr. Joule before the Manchester
Literary and Philosophical Society on December 1, 1863, he refers to
subsequent observations and estimates 116 miles as “the elevation
at which meteors in general are first observed”—_i.e._, where our
atmosphere is sufficiently dense to generate a white-heat by the
resistance it offers to the rapidly flying meteor.
It is curious to observe how, in dealing with actual physical facts,
a mathematician of the solid practical character of Joule becomes
compelled to practically throw overboard the orthodox theory of
limited atmospheric extension. Here, in making his calculations of the
resistance of atmospheric matter at this elevation, he bases them on
the assumption of a decrease of density at the rate of “one quarter for
every seven miles,” and indicates no limit at which this rate shall
vary. Very simple arithmetic is sufficient to show that this leads us
to the unlimited atmospheric extension, for which I have contended we
may go on for ever taking off a quarter at every seven miles, and there
will still remain the three quarters of the quantity upon which we last
operated, or, more practically stated, we shall thus go on seven after
seven until we reach the boundaries of the atmospheric grasp of the
gravitation of some other sphere.
Surely the time has arrived for the full reconsideration of this
fundamental question of whether the universe is filled with atmospheric
matter or is the vacuum of the molecular mathematicians plus the
imaginary “ether,” which has been invented by its mathematical creators
only to extricate them from the absurd dilemma into which they are
plunged when they attempt to explain the transmission of light and heat
by undulations traveling through space containing nothing to undulate.
They have filled it with immaterial matter evolved entirely from their
own consciousness, which they have gratuitously endowed with whatever
properties are required for the fitting of their theories—properties
that are self-contradictory and without any counterpart in anything
seen or known outside of the fertile imagination of these reckless
theorists.
We know of nothing that can penetrate every form of matter without
adding either to its weight or its bulk; we know of nothing that
can communicate motion to ponderable matter without itself being
ponderable—_i.e._, having the primary property of matter, viz., mass,
or weight, and consequent _vis viva_ when moving; we know of nothing
that can set bodies in motion without proportionally resisting the
motion of bodies through it; and if the waving of the ether is (as
Tyndall describes it) “as real and as truly mechanical as the breaking
of sea-waves upon the shore,” the material of the breakers must be
like the “jelly” to which he compares it, and have some viscosity, or
resistance to penetration, or pushing aside.
We have not a shadow of direct evidence of the existence of the
“interatomic” spaces occupied by the other, and in the midst of which
the atoms are made to theoretically swing, nor even of the existence of
the atoms themselves.
The “ether” of to-day, with its imaginary penetration and its material
action without material properties, has merely taken the place of the
equally imaginary phlogiston, caloric, electric, and magnetic fluids,
the “imponderables” of the past. I have little doubt that ere long
the modern modification of these physical superstitions will share
their fate, and we shall all adopt the simple conception that heat,
light, end electricity are, like sound, merely transmissible states or
affections of matter itself regarded bodily, as it is seen and felt to
exist.
This may possibly throw a good many mathematicians out of work—or into
more useful work; but, however that may be, it will certainly aid the
general diffusion of science as the intellectual inheritance of every
human being. At present the explanations of the simple phenomena of
light and heat are incomparably more difficult to understand and to
account for than the facts which they attempt to elucidate.
A NEGLECTED DISINFECTANT.
When the household of our grandmothers was threatened with infection,
the common practice was to sprinkle brimstone on a hot shovel or on hot
coals on a shovel, and carry the burning result through the house. But
now this simple method of disinfecting has gone out of fashion without
any good and sufficient reason. The principal reason is neither good
nor sufficient, viz., that nobody can patent it and sell it in shilling
and half-crown bottles.
On September 18th last, M. d’Abbadie read a paper at the Academy of
Sciences on “Marsh Fevers,” and stated that in the dangerous regions
of African river mouths immunity from such-fevers is often secured by
sulphur fumigations on the naked body. Also that the Sicilian workers
in low ground sulphur mines suffer much less than the rest of the
surrounding population from intermittent fevers. M. Fouqué has shown
that Zephyria (on the volcanic island of Milo or Melos, the most
westerly of the Cyclades), which had a population of 40,000 when it
was the centre of sulphur-mining operations, became nearly depopulated
by marsh fever when the sulphur-mining was moved farther east, and
the emanations prevented by a mountain from reaching the town. Other
similar cases were stated.
It is well understood by chemists that bleaching agents are usually
good disinfectants; that which can so disturb an organic compound as
to destroy its color, is capable of either arresting or completing
the decompositions that produce vile odors and nourish the organic
germs or ferments which usual accompany, or, as some affirm, cause
them. Sulphurous acid is, next to hypochlorous acid, one of the most
effective bleaching agents within easy reach.
I should add that sulphurous acid is the gas that is _directly_ formed
by burning sulphur. By taking up another dose of oxygen it becomes
sulphuric acid, which, combined with water, is oil of vitriol. The
bleaching and disinfecting action of the sulphurous acid is connected
with its activity in appropriating the oxygen which is loosely held
or being given off by organic matter. Chlorine and hypochlorous
acid (which is still more effective than chlorine itself) act in the
opposite way, so do the permanganates, such as Condy’s fluid, etc. They
supply oxygen in the presence of water. It is curious that opposite
actions should produce like results. A disquisition on this and its
suggestions would carry me beyond the limits of a note.
ANOTHER DISINFECTANT.
The above-named disinfectants are objectionable on account of their own
odors and their corrosive action. Both sulphurous acid and hypochlorous
acid (the active principle of the so-called “chloride of lime”) have a
disagreeable habit of rusting iron and suggesting antique green bronzes
by their action on brass ornaments. Under serious conditions this
should be endured, but in many cases where the danger is not already
developed, the desired end may be attained without these annoyances.
Sulphate of copper, which is not patented or “brought out” by a limited
company, may be bought at its fair retail value of 6_d._ or less per
lb. (the oil-shop name for it is “blue vitriol”), in crystals, readily
soluble in water.
I have lately used it in the case of a trouble to which English
households are too commonly liable, and one that has in many cases done
serious mischief. The stoppage of a soil-pipe caused the overflow of a
closet, and a consequent saturation of floor boards, that in time would
probably have developed danger by nourishing and developing those germs
of bacteria, bacilli, etc., which abound in the air, and are ready to
increase and multiply wherever their unsavory food abounds.
By simply mopping the floor with a solution of these green crystals,
and allowing it to soak well into the pores of the wood, they cease to
become a habitat for such microscopic abominations. The copper-salt
poisons the poisoners.
Dr. Burg goes so far as to recommend that building materials, articles
of furniture, and clothing, etc., should be injected with sulphate
of copper, in order to avert infection, and in support of this refers
to the immunity of workers in copper from cholera, typhoid fever, and
infectious diseases generally.
I agree with him to the extent of suggesting the desirability of
occasionally mopping house floors with this solution. Its visible
effects on the wood are first to stain it with a faint green tinge
which gradually tones down to a brown stain, giving to deal the
appearance of oak, a change which has no disadvantage from an artistic
point of view. If the wood is already tainted with organic matter
capable of giving off sulphureted hydrogen, the darkening change is
more rapid and decided, owing to the formation of sulphide of copper.
The solution of sulphate should not be put into iron or zinc vessels,
as it rapidly corrodes them, and deposits a non-adherent film of
copper. It will even disintegrate common earthenware, by penetrating
the glaze, and crystallizing within the pores of the ware, but this is
a work of time (weeks or months). Stoneware resists this, and wooden
buckets may be used safely. It is better to keep the crystals and
dissolve when required. Ordinary earthenware may be used with impunity
if washed immediately afterwards.
ENSILAGE.
This subject has been largely expounded and discussed lately in the
_Times_ and other newspapers. As most of my readers are doubtless
aware, it is simply a substitute for haymaking, by digging pits, paving
and building them round with stone or concrete, then placing the green
fodder therein and covering it over with sufficient earth to exclude
the air.
We are told that very inferior material (such as coarse maize grass
mixed with chaff) when thus preserved gives better feeding and milking
results than good English hay.
I may mention a very humble experience of my own that bears upon
this. When a boy, I was devoted to silkworms, and my very small supply
of pocket-money was over-taxed in the purchase of exorbitantly small
pennyworths of mulberry leaves at Covent Garden. But a friend in the
country had a mulberry tree, and at rather long intervals I obtained
large supplies, which, in spite of all my careful wrapping in damp
cloths, became rotted in about ten days. I finally tried digging a hole
and burying them. They remained fresh and green until all my silkworms
commenced the working and fasting stage of their existence. This was
ensilage on a small scale.
The correspondence in the newspapers has suggested a number of reasons
why English farmers do not follow the example of their continental
neighbors in this respect; climate, difference of grasses, etc., etc.,
are named, but the real reason why this is commercially impossible, and
farming, properly so called, is becoming a lost art in England (mere
meadow or prairie grazing gradually superseding it) is not named in any
part of the discussion that I have read.
I refer to the cause which is abolishing the English dairy, which
drives us to the commercial absurdity of importing fragile eggs from
France, Italy, Spain, etc., apples from the other side of the Atlantic,
tame house-fed rabbits from Belgium, and so on, with all other
agricultural products which are precisely those we are _naturally_ best
able to produce at home; I mean _those demanding a small area of land
and a proportionately large amount of capital and labor_. A poultry
or rabbit farm, acre for acre, demands fully ten times the capital,
ten times the labor, and yields ten times the produce obtained by our
big-field beef and mutton graziers.
The scientific and economic merits of ensilage are probably all that
is claimed for it, and it is especially adapted for our uncertain
haymaking climate, but what farmer who is merely a lodger on the land,
holding it as an annual tenant-at-will or under a stinted beggarly
lease of 21 years, would expend his capital in building a costly
_silo_, which becomes by our feudal laws and usages the absolute
property of the landlord?
Our tenant farmers employ the latest and best achievements of
engineering science in the form of implements, but take care that
they shall be _upon wheels_, or otherwise non-fixtures, and use rich
chemically prepared manures, provided they are not permanent, while
they abstain from improvements which involve any serious outlay in the
form of fixtures on the land. Those who lecture them about their want
of enterprise should always remember that their condition is merely
a form of feudal serfdom, tempered by the possession of capital, and
that all their agricultural operations are influenced by a continual
struggle to prevent their capital from falling into the hands of the
feudal lord. Anybody who has ever read an ordinary form of English
farm-lease, with its prohibitions concerning the sale of hay and straw,
and restrictions to “four-course,” or other mode of cultivation,
must see the hopelessness of any development of British agriculture
comparable to that of British commerce and manufactures.
Imagine the condition of a London shopkeeper or Midland manufacturer
holding his business premises as a yearly tenant, liable at six months’
notice to quit, with confiscation of all his business fixtures.
THE FRACTURE OF COMETS.
The view of the constitution of comets expounded in one of my notes
of April last, viz., that they are meteoric systems consisting of a
central mass, or masses, round which a multitude of minor bodies are
revolving like satellites around their primary, is strongly confirmed
by the curious proceedings of the present comet, which proceedings also
justify my last note of last month pointing out the omission of our
astronomers, who have neglected the positive and irregular repulsive
action of the sun upon comets, that, like the great comets of 1843,
1880, and 1882, come within a few hundred thousand miles of the visible
solar surface.
The solar prominences are stupendous eruptions from the sun,
consisting, as the spectroscope demonstrates, of hydrogen flames and
incandescent metallic vapors ejected with furious violence to visible
distances ranging from ten or twenty to above three hundred thousand
miles, but this flame shown by the spectroscope is but the flash of
the gun, the actual ejection proceeding vastly farther, far beyond
the limits of the corona, as described in last month’s notes. These
eruptions are so abundant that Secchi alone observed and recorded 2767
in one year (1871). Speaking generally, the sun is never free from
them, and they proceed from all parts of the sun, but most abundantly
from the sun-spot zones.
A system of meteoric bodies such as I suppose to form a comet (I mean
the comet as it exists in space before the generation of its tail,
which is only formed as it approaches the sun) could not approach
so near to the sun as did the present comet at perihelion, without
encountering more or less of these furious blasts the flash of some of
which have been seen to move with a measurable mean velocity of above
300 miles per second, and a probable maximum velocity sufficient to
eject solid matter beyond the reclaiming grasp of solar gravitation.
It is evident that such a meteoric system as I suppose to constitute
a comet would, in the course of a rapid perihelion flight crossing
these outblasts, be liable to various degrees of ejection in different
parts, that would disturb its original structure by blowing some of its
constituents out of their orbits, or even quite away from the control
of the feeble gravitation of the general meteoric mass, and thus
effecting a rupture of the comet.
Now such a disintegration or dispersion of the present comet has been
actually observed. Several able observers have described a breaking of
the head of this comet shortly after its perihelion passage. Commander
Sampson’s observations with the great 26-inch equatorial telescope of
the Washington Naval Observatory are very explicit. On October 25 he
saw the nucleus as a single well-defined globular body. On November 3,
with the same telescope, he saw a triple nucleus, due to the formation
of two additional minor bodies. These were more distinctly seen on
November 6. Mr. W. R. Brooks, of New York, saw a detached fragment
of the comet which afterwards faded out of view. Professor Schmidt
observed another and similar fragment which has likewise disappeared.
All these observations indicate disruption due to some disturbing
force, acting with different degrees of violence upon different
portions of the comet.
Minor disturbances of this kind will, I think, account for the trail
of meteoric bodies which Schiaparelli has shown to follow the paths of
other comets. A great disturbance might give quite a new orbit to the
meteoric fragments.
These considerations suggest another and a curious view of the question
of possible cometary collision with the sun, viz., that a comet might
be traveling in such an orbit as to make it mathematically due to
plunge obliquely beneath the solar surface at its next perihelion; but
on its approach to the surface of the sun it might encounter so violent
an outrush of solar-prominence matter as to drive it bodily out of its
course, and avert the threatened peril to its existence.
THE ORIGIN OF COMETS.
We read in story-books of uncomfortable people who have cherished a
guilty secret in their bosoms, that it has “gnawed their vitals,”
until at last they have carried it to the grave. I have such a secret
that does the gnawing business whenever I write or speak of comets,
concerning the origin of which I am guilty of an hypothesis that has
hitherto been cherished as aforesaid from the very shame of adding
another to an already exaggerated heap of speculations on celestial
physics.
It assumes, in the first place, that all the other suns which we see as
stars are constituted like our own sun; that they eject great eruptions
similar to the prominences above described, and even of vastly greater
magnitude, as in the case of the flashing stars that have excited
so much wonderment among astronomers, but which I regard simply as
suns like ours, subject, like ours, to periodic maximum and minimum
activities, but of greater magnitude.
If such is the case, some of the prominence matter or vaporous
constituents of these suns must be ejected with much greater
proportional violence than are those from our sun. But those from our
sun have been proved to rush out on some occasions with a velocity so
great that the solar gravitation cannot bring them back. If such is
ever the case with the explosions of our sun, it must be of frequent
occurrence with the greater explosions of certain stars, and therefore
vast quantities of meteoric matter are continually ejected into space,
and traveling there until they come within the gravitation domain of
some other sun like ours, when they will necessarily be bent into such
orbits as those of comets.
But what will be the nature of this meteoric matter?
If from our sun, it would be a multitude of metallic hailstones, due to
the condensation of the metallic vapor by cooling as it leaves the sun,
and such meteoric hail would correspond to the meteoric stones that
fall upon our earth, and which, for reasons stated in “The Fuel of the
Sun,” I believe to be of solar origin. Besides these, there would be
ice-hail, such as Schevedorf claims to be meteoric.
A star mainly composed of hydrogen and carbon, or densely enveloped in
these gases (as the spectroscope indicates to be the case in some of
these flashing stars), would eject hydrocarbon vapors, condensible by
cooling into solids similar to those we obtain by the condensation of
terrestrial hydrocarbon vapors (paraffin, camphor, turpentine, and all
the essential oils, for example), and thus we should have the meteoric
systems composed of these particles circulating about their own common
centre of mass as above stated, and displaying the spectrum which Dr.
Huggins has found common to comets.
If this is correct, the present comet comes from a sun that contains
metallic sodium in addition to the hydrocarbons, as the spectrum of
this metal was seen when this comet was near enough to the sun to
render its vapor incandescent.
FOOTNOTES
[1] Up to the present date (1882) nobody, as far as I know, has
questioned my figures or defended those of Wollaston. Sir William Grove
has written to me, pointing out his own anticipations of my conclusions
respecting the universality of atmospheric matter. Sir Charles Lyell,
before his death, expressed very strong approval of my conclusions, and
many other men of scientific eminence have done the same. To expect
any immediate, unreserved adoption of such bold speculations would be
unreasonable.
[2] Since the above was written these analogies have been generally
accepted.
[3] Since the publication of “The Fuel of the Sun,” Mr. Norman Lockyer
has adopted this view of solar dissociation, and has gone so far as
to suppose that it splits metals and other substances regarded by
modern chemists as simple elements into more elementary and simple
constituents. He assumes that the temperature of the solar atmosphere,
growing higher at increasing depths, becomes somewhere capable of doing
far greater dissociation work than that which separates the hydrogen
of the prominences revealed by the spectroscope. In putting forth this
“working hypothesis” he seems to have lost sight of the fact clearly
proved by Deville’s experiments, that the temperature of dissociation
rises with the pressure to which the compound is subjected, and
thus that within the bowels of the sun the metals will be far less
dissociable than they are on the surface of our earth.
[4] Still more recently (1882) the magnificent photographs of Jannsen
have displayed further evidence of the flame-tongue character of the
mottling.
[5] Subsequent observations (1882) by Secchi, Young, and others have
demonstrated velocities far exceeding this; quite sufficient to project
the solid matter clearly beyond the sphere of solar attraction.
[6] My first memorandum on this subject is dated April 23, 1840, in a
_Register of Ideas_, then commenced in very early student days.
[7] Any reader of “The Fuel of the Sun” will perceive that the vaporous
envelope which I have described as “an effectual jacket for limiting
the amount of radiation,” is a complete theoretical anticipation and
explanation of the “solar crust” of Respighi and the “Trennungschicht”
of Zöllner. We agree perfectly in our conclusions, though arriving at
them by such very different paths, and so independently of each other.
[8] What did he smell? Was it an emanation from the soles of my feet?
If so, how did this aura get through the soles of my boots, which
were thick? It could scarcely have been the odor of the boot soles
themselves that he followed, as he recognized me afterwards at some
distance. This suggests an interesting experiment, that anybody owning
one of these dogs may easily try. Make a similar track to mine, but
when on the way, take off the boots you wore on starting and change
them for some one else’s boots, or a new pair, and watch the result
from the window.
[9] “The Fuel of the Sun,” Chapters iv. to x.
[10] Since this was written some such modifications have been made with
equivocal results.
[11] _Nature_, vol. xiv. p. 429.
[12] See Chapter on “The Origin of Lunar Volcanoes.”
[13] The burnt card, burnt bamboo, and other flimsy incandescent
threads now (1882) in vogue, merely represent Starr’s preliminary
failures prior to his adoption of the hard adamantine stick of
retort-carbon, which I suppose will be duly re-invented, patented
again, and form the basis of new Limited Companies, when the present
have collapsed.
[14] Hull, “On the Coal-fields of Great Britain.”
[15] “The Great Ice Age, and its Relation to the Antiquity of Man.” By
James Geikie, F.R.S., etc. Second edition, revised, 1877. Daldy and
Isbister.
[16] The terminal moraine at the Oxfjord station, which I have already
mentioned as the only ancient example of an ordinary moraine that
I have seen in Arctic Norway, was, of course, a special object of
interest to me. Further observation showed that it does not merely
consist of the heap of stones I noticed in 1856, which appears like
a disturbed talus cut through and heaped up at its lower part, but
that there is another moraine adjoining it, or in continuation with
it, which is covered with vegetation, and stretches quite across the
mouth of the valley. The Duke of Roxburgh, who is well acquainted with
this neighborhood, having spent sixteen summers in Arctic Norway, was
one of our fellow-passengers, and told me that this moraine forms a
barrier that dams up the waters of a considerable lake, abounding with
remarkably fine char. I learned this just as the packet was starting,
too late to go on shore even for a few minutes, and obtain a view
of this lake and the valley beyond. This I regret, as it might have
revealed some explanation of the exceptional nature of this moraine.
It would be interesting to learn whether it belongs to the greater
ice age, or to that period of minor glaciation that fashioned the
farm patches already described. The formation of the lake is easily
understood in the latter case. It is only required that such a minor
reglaciated valley as one of these should be of larger magnitude and
of very gentle inclination at its lower part, so that the secondary
glacier should die out before reaching the present seashore. It would
then deposit its moraine across the mouth of the valley, and this
moraine would dam up the waters which such a valley must necessarily
receive from the drainage of its hilly sides. Llyn Idwal, in North
Wales, is a lake thus formed.
[17] See “Through Norway with a Knapsack,” chapters xi. and xii., for
further descriptions of these.
[18] Lyell, “Elements of Geology,” p. 159.
[19] The celebrated “Maelström” is one of the currents that flow down
the submarine incline between these islands when the tide is falling.
Although I have ridiculed some of the accounts of this now innocent
stream, I am not prepared to assert that it was always as mild as at
present. If the ancient glaciers were stopped suddenly, as they may
well have been, by the rocky barrier of Mosken, between Vaerö and
Moskenesö, and they then suddenly concluded their deposition of till, a
precipice must have been formed between this and the deep sea outside
the islands, down which the sea would pitch when the tide was falling,
and thus form some dangerous eddies. This cascade would gradually
obliterate itself by wearing down the precipitous wall to an inclined
plane such as at present exists, and down which the existing current
flows.
[20] The largest of the Norwegian lakes, the Mjosen, is 1550 feet deep,
and its surface 385 feet above the sea-level. Its bottom is about 1000
feet lower than the sea outside, or 500 to 800 feet below the bottom
of the Christiana Fjord. The fjords, generally speaking, are very much
shallower near their mouths than further inland, as though their depth
had been determined by the thickness of the glaciers flowing down them,
and the consequent limits of flotation and deposition.
[21] This has been recently overcome to a great extent by using
glycerine instead of water.
[22] Since the above was written I have made some experiments with a
solution of shellac in borax (obtained by long boiling), and hereby
claim the invention of its application to this purpose, in order to
prevent anybody from patenting it. I shall not do so myself.
[23] Written during the coal famine of 1872–73.
[24] From 1870 to 1880 the amount has risen from 110,431,192 to
146,818,622 tons per annum, an average increase of 3,638,743 tons per
annum.
[25] At the present time (1882) we are receiving the excessive supplies
consequent upon the opening of new pits that, under the stimulus
of high prices, were in the course of sinking when the above was
written. Hence the present low prices. Presently the annual increase
of consumption will overtake this increased supply, and another “coal
famine” like that then existing will follow. This is not far distant.
[26] “The Coal Fields of Great Britain,” pp. 447, 448.
[27] In a paper on the Comstock mines, read at the Pittsburg meeting
of the American Institute of Mining Engineers in 1879, by Mr. John A.
Church, the hot mine waters are described as reaching 158° Fahr. (so
hot that men have been scalded to death by falling into them). The
highest recorded _air temperature_ there is 128°. These are silver
mines, and vigorously worked in spite of this temperature and great
humidity. A much higher temperature is endurable in _dry air_.
[28] The scientific pedant of the Middle Ages displayed his profundity
by continually quoting Aristotle and other “ancients.” His modern
successor does the like by decorating his pages with displays of
algebraical formulæ. In order to secure the proper respect of _my_
readers I here repeat the equation that I enunciated many years ago,
“_c_ = _s_/_p_” where _c_ stands for civilization, _s_ for the quantity
of soap consumed per annum, and _p_ the population of a given community.
[29] Geologists who may be interested in seeing the results of this
experiment, will find on the Edgbaston Vestry Hall, in Enville Road,
near the Five Ways, Birmingham, some columns, massive window pieces,
doorways, and ornamental steps cast from the fused Rowley Rag and
slowly cooled.
[30] In each of my three visits to America 1 lost about thirty pounds
in weight, which I recovered within a few months of my return to the
“home country” (of English-speaking nations).—RICHARD A. PROCTOR.
[31] Since the above was written, a correspondent in Paris tells me
that a caricature exists, representing a Frenchman enjoying an open
fire by standing on his head in the middle of the room.
[32] See foot-note, page 365.
[33] I tried the seeds given to me by Messrs. Carter, and find them
to produce the same plant as my own, which I still cultivate very
successfully. I now sow it in the spring as a kitchen garden border.
[34] Subsequent experiments induce me not to recommend this economy, on
account of the bagging which results from excessive width between the
frames; 3 feet should not be exceeded.
[35] I have followed up Mr. Trewby’s hint, and find that more than
one quality of scrim is made. The best, made entirely of flax, costs
rather more than the 2¼_d._ stated in the estimate, but it is the
cheapest practically. The best I have seen is that used in the Houses
of Parliament.
[36] Watt’s own figure for the latent heat of steam at 212° was 950°,
but I adopt that which is now generally accepted.
Transcriber’s Notes
Punctuation and spelling were made consistent when a predominant
preference was found in this book; otherwise they were not changed.
The original text contained many typographical errors. The simple ones
were corrected without comment here; others are noted below.
Unbalanced quotation marks were corrected, as proper placement always
could be determined.
Some typographical errors probably remain undetected.
Ambiguous hyphens at the ends of lines were retained; occurrences of
inconsistent hyphenation have not been changed.
Text uses both “Acadamy” and “Academy”; both retained here.
Page 336: “The disagreeable sensation experienced by Dr. Siemens in the
stove-heated railway cars, etc., were probably due to this” was printed
that way. Either “sensation” should be “sensations” or “were” should be
“was”.
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