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Title: Scientific American Supplement, No. 643, April 28, 1888
Author: Various
Language: English
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*** Start of this LibraryBlog Digital Book "Scientific American Supplement, No. 643, April 28, 1888" ***
[Illustration]
SCIENTIFIC AMERICAN SUPPLEMENT NO. 643
NEW YORK, APRIL 28, 1888
Scientific American Supplement. Vol. XXV., No. 643.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. ARCHÆOLOGY.--The Subterranean Temples of India.--The
subterranean temples of India described and illustrated, the
wonderful works of the ancient dwellers in Hindostan.--3
illustrations. 10275
II. BIOGRAPHY.--General F. Perrier.--Portrait and biography of
the French geodesian, his triangulations in Algiers and
Corsica.--1 illustration. 10264
The Crown Prince of Germany--Prince William and his son.--
Biographical note of Prince William, the heir to the German
throne.--1 illustration. 10263
III. BIOLOGY.--Poisons.--Abstract of a lecture by Prof. MEYMOTT
TIDY, giving the relations of poisons to life. 10273
The President's Annual Address to the Royal Microscopical
Society.--The theory of putrefaction and putrefactive
IV. CHEMISTRY.--Molecular Weights.--A new and simple method
of determining molecular weights for unvolatilizable
substances. 10271
V. CIVIL ENGINEERING.--Concrete.--By JOHN LUNDIE.--A practical
paper on the above subject.--The uses and proper methods of
handling concrete, machine mixing contrasted with hand
mixing. 10267
Timber and Some of its Diseases.--By H. MARSHALL WARD.--The
continuation of this important treatise on timber destruction,
the fungi affecting wood, and treatment of the troubles
arising therefrom. 10277
VI. ENGINEERING.--Estrade's High Speed Locomotive.--A comparative
review of the engineering features of M. Estrade's new
engine, designed for speeds of 77 to 80 miles an hour.--1
illustration. 10266
Machine Designing.--By JOHN B. SWEET.--First portion of a
Franklin Institute lecture on this eminently practical
subject.--2 illustrations. 10267
VII. METEOROLOGY.--The Peak of Teneriffe.--Electrical and
meteorological observations on the summit of Teneriffe. 10265
VIII. MISCELLANEOUS.--Analysis of a Hand Fire Grenade.--By
CHAS. CATLETT and R.C. PRICE.--The contents of a fire
grenade and its origin. 10271
How to Catch and Preserve Moths and Butterflies.--Practical
directions for collectors. 10275
The Clavi Harp.--A new instrument, a harp played by means of
keys arranged on a keyboard--1 illustration. 10275
Inquiries Regarding the Incubator.--By P.H. JACOBS.--Notes
concerning the incubator described in a previous issue
(SUPPLEMENT, No. 630).--Practical points. 10265
IX. PHYSICS.--The Direct Optical Projection of Electro-dynamic
Lines of Force, and other Electro-dynamic Phenomena.--By Prof.
J.W. MOORE--Second portion of this profusely illustrated paper,
giving a great variety of experiments on the phenomena of
loop-shaped conductors.--26 illustrations. 10272
The Mechanics of a Liquid.--An ingenious method of measuring
the volume of fibrous and porous substances without immersion
in any liquid.--1 illustration. 10269
X. PHYSIOLOGY.--Artificial Mother for Infants.--An apparatus
resembling an incubator for infants that are prematurely
born.--Results attained by its use.--1 illustration. 10274
Gastrostomy.--Artificial feeding for cases of obstructed
oesophagus.--The apparatus and its application.--2
illustrations. 10274
XI. PHOTOGRAPHY.--How to Make Photo-Printing Plates.--The
process of making relief plates for printers. 10271
XII. TECHNOLOGY.--Improved Current Meter.--A simple apparatus
for measuring air and water currents without indexes or other
complications.--1 illustration. 10270
The Flower Industry of Grasse.--Methods of manufacturing
perfumes in France.--The industry as practiced in the town
of Grasse. 10270
Volute Double Distilling Condenser.--A distiller and condenser
for producing fresh water from sea water.--3 illustrations. 10269
The Argand Burner.--The origin of the invention of the Argand
burner. 10275
* * * * *
[Illustration: THE CROWN PRINCE OF GERMANY--PRINCE WILLIAM AND SON
[From a Photograph]]
THE CROWN PRINCE OF GERMANY--PRINCE WILLIAM AND HIS SON.
At a moment when the entire world has its eyes fixed upon the invalid
of the Villa Zurio, it appears to us to be of interest to publish the
portrait of his son, Prince William. The military spirit of the
Hohenzollerns is found in him in all its force and exclusiveness. It
was hoped that the accession of the crown prince to the throne of
Germany would temper the harshness of it and modernize its aspect, but
the painful disease from which he is suffering warns us that the
moment may soon come in which the son will be called to succeed the
Emperor William, his grandfather, of whom he is morally the perfect
portrait. Like him, he loves the army, and makes it the object of his
entire attention. No colonel more scrupulously performs his duty than
he, when he enters the quarters of the regiment of red hussars whose
chief he is.
His solicitude for the army manifests itself openly. It is not without
pride that he regards his eldest son, who will soon be six years old,
and who is already clad in the uniform of a fusilier of the Guard.
Prince William is a soldier in spirit, just as harsh toward himself as
severe toward others. So he is the friend and emulator of Prince Von
Bismarck, who sees in him the depositary of the military traditions of
the house of Prussia, and who is preparing him by his lessons and his
advice to receive and preserve the patrimony that his ancestors have
conquered.
Prince William was born January 27, 1859. On the 29th of February,
1881, he married Princess Augusta Victoria, daughter of the Duke of
Sleswick-Holstein. Their eldest son, little Prince William,
represented with his father in our engraving, was born at Potsdam, May
6, 1882.--_L'Illustration._
* * * * *
GENERAL F. PERRIER.
Francois Perrier, who was born at Valleraugue (Gard), on the 18th of
April, 1835, descended from an honorable family of Protestants, of
Cevennes. After finishing his studies at the Lyceum of Nimes and at
St. Barbe College, he was received at the Polytechnic School in 1853,
and left it in 1857, as a staff officer.
Endowed with perseverance and will, he owed all his grades and all his
success to his splendid conduct and his important labors. Lieutenant
in 1857, captain in 1860, major of cavalry in 1874, lieutenant-colonel
in 1879, he received a year before his death the stars of
brigadier-general. He was commander of the Legion of Honor and
president of the council-general of his department.
General Perrier long ago made a name for himself in science. After
some remarkable publications upon the trigonometrical junction of
France and England (1861) and upon the triangulation and leveling of
Corsica (1865), he was put at the head of the geodesic service of the
army in 1879. In 1880, the learned geodesian was sent as a delegate to
the conference of Berlin for settling the boundaries of the new
Greco-Turkish frontiers. In January of the same year, he was elected a
member of the Academy of Sciences, as successor to M. De Tessan. He
was a member of the bureau of longitudes from 1875.
In 1882, Perrier was sent to Florida to observe the transit of Venus.
Thanks to his activity and ability, his observations were a complete
success. Thenceforward, his celebrity continued to increase until his
last triangulating operations in Algeria.
[Illustration: GENERAL FRANCOIS PERRIER.]
"Do you not remember," said Mr. Janssen recently to the Academy of
Sciences, "the feeling of satisfaction that the whole country felt
when it learned the entire success of that grand geodesic operation
that united Spain with our Algeria over the Mediterranean, and passed
through France a meridian arc extending from the north of England as
far as to the Sahara, that is to say, an arc exceeding in length the
greatest arcs that had been measured up till then? This splendid
result attracted all minds, and rendered Perrier's name popular. But
how much had this success been prepared by long and conscientious
labors that cede in nothing to it in importance? The triangulation and
leveling of Corsica, and the connecting of it with the Continent; the
splendid operations executed in Algeria, which required fifteen years
of labor, and led to the measurement of an arc of parallels of nearly
10° in extent, that offers a very peculiar interest for the study of
the earth's figure; and, again, that revision of the meridian of
France in which it became necessary to utilize all the progress that
had been made since the beginning of the century in the construction
of instruments and in methods of observation and calculation. And it
must be added that General Perrier had formed a school of scientists
and devoted officers who were his co-laborers, and upon whom we must
now rely to continue his work."
The merits of General Perrier gained him the honor of being placed at
the head of a service of high importance, the geographical service of
the army, to the organization of which he devoted his entire energy.
In General Perrier, the man ceded in nothing to the worker and
scientist. Good, affable, generous, he joined liveliness and good
humor with courage and energy. Incessantly occupied with the
prosperity and grandeur of his country, he knew that true patriotism
does not consist in putting forth vain declamations, but in
endeavoring to accomplish useful and fruitful work.--_La Nature._
General Perrier died at Montpellier on the 20th of February, 1888.
* * * * *
THE PRESIDENT'S ANNUAL ADDRESS TO THE ROYAL MICROSCOPICAL SOCIETY.[1]
[Footnote 1: Delivered by the Rev. Dr. Dallinger, F.R.S., at the
annual meeting of the Royal Microscopical Society, Feb. 8,
1888.--_Nature._]
Retrospect may involve regret, but can scarcely involve anxiety. To
one who fully appreciates the actual, and above all the potential,
importance of this society in its bearing upon the general progress of
scientific research in every field of physical inquiry, the
responsibilities of president will not be lightly, while they may
certainly be proudly, undertaken.
I think it may be now fairly taken for granted that, as this society
has, from the outset, promoted and pointed to the higher scientific
perfection of the microscope, so now, more than ever, it is its
special function to place this in the forefront as its _raison
d'etre_. The microscope has been long enough in the hands of amateur
and expert alike to establish itself as an instrument having an
application to every actual and conceivable department of human
research; and while in the earliest days of this society it was
possible for a zealous Fellow to have seen, and been more or less
familiar with, all the applications to which it then had been put, it
is different to-day. Specialists in the most diverse areas of research
are assiduously applying the instrument to their various subjects, and
with results that, if we would estimate aright, we must survey with
instructed vision the whole ground which advancing science covers.
From this it is manifest that this society cannot hope to infold, or
at least to organically bind to itself, men whose objects of research
are so diverse.
But these are all none the less linked by one inseverable bond; it is
the microscope; and while, amid the inconceivable diversity of its
applications, it remains manifest that this society has for its
primary object the constant progress of the instrument--whether in its
mechanical construction or its optical appliances; whether the
improvements shall bear upon the use of high powers or low powers;
whether it shall be improvement that shall apply to its commercial
employment, its easier professional application, or its most exalted
scientific use; so long as this shall be the undoubted aim of the
Royal Microscopical Society, its existence may well be the pride of
Englishmen, and will commend itself more and more to men of all
countries.
This, and this only, can lift such a society out of what I believe has
ceased to be its danger, that of forgetting that in proportion as the
optical principles of the microscope are understood, and the theory of
microscopical vision is made plain, the value of the instrument over
every region to which it can be applied, and in all the varied hands
that use it, is increased without definable limit. It is therefore by
such means that the true interests of science are promoted.
It is one of the most admirable features of this society that it has
become cosmopolitan in its character in relation to the instrument,
and all the ever-improving methods of research employed with it. From
meeting to meeting it is not one country, or one continent even, that
is represented on our tables. Nay, more, not only are we made familiar
with improvements brought from every civilized part of the world,
referring alike to the microscope itself and every instrument devised
by specialists for its employment in every department of research; but
also, by the admirable persistence of Mr. Crisp and Mr. Jno. Mayall,
Jr., we are familiarized with every discovery of the old forms of the
instrument wherever found or originally employed.
The value of all this cannot be overestimated, for it will, even where
prejudices as to our judgment may exist, gradually make it more and
more clear that this society exists to promote and acknowledge
improvements in every constituent of the microscope, come from
whatever source they may; and, in connection with this, to promote by
demonstrations, exhibitions, and monographs the finest applications of
the finest instruments for their respective purposes.
To give all this its highest value, of course, the theoretical side of
our instrument must occupy the attention of the most accomplished
experts. We may not despair that our somewhat too practical past in
this respect may right itself in our own country; but meantime the
splendid work of German students and experts is placed by the wise
editors of our journal within the reach of all.
I know of no higher hope for this important society than that it may
continue in ever increasing strength to promote, criticise, and
welcome from every quarter of the world whatever will improve the
microscope in itself and in any of its applications, from the most
simple to the most complex and important in which its employment is
possible.
There are two points of some practical interest to which I desire for
a few moments to call your attention. The former has reference to the
group of organisms to which I have for so many years directed your
attention, viz., the "monads," which throughout I have called
"putrefactive organisms."
There can be no longer any doubt that the destructive process of
putrefaction is essentially a process of fermentation.
The fermentative saprophyte is as absolutely essential to the setting
up of destructive rotting or putrescence in a putrescible fluid as the
torula is to the setting up of alcoholic fermentation in a saccharine
fluid. Make the presence of torulæ impossible, and you exclude with
certainty fermentative action.
In precisely the same way, provide a proteinaceous solution, capable
of the highest putrescence, but absolutely sterilized, and placed in
an optically pure or absolutely calcined air; and while these
conditions are maintained, no matter what length of time may be
suffered to elapse, the putrescible fluid will remain absolutely
without trace of decay.
But suffer the slightest infection of the protected and pure air to
take place, or, from some putrescent source, inoculate your sterilized
fluid with the minutest atom, and shortly turbidity, offensive scent,
and destructive putrescence ensue.
As in the alcoholic, lactic, or butyric ferments, the process set up
is shown to be dependent upon and concurrent with the vegetative
processes of the demonstrated organisms characterizing these ferments;
so it can be shown with equal clearness and certainty that the entire
process of what is known as putrescence is equally and as absolutely
dependent on the vital processes of a given and discoverable series of
organisms.
Now it is quite customary to treat the fermentative agency in
putrefaction as if it were wholly bacterial, and, indeed, the
putrefactive group of bacteria are now known as saprophytes, or
saprophytic bacteria, as distinct from morphologically similar, but
physiologically dissimilar, forms known as parasitic or pathogenic
bacteria.
It is indeed usually and justly admitted that _B. termo_ is the
exciting cause of fermentative putrefaction. Cohn has in fact
contended that it is the distinctive ferment of all putrefactions, and
that it is to decomposing proteinaceous solutions what _Torula
cerevisiæ_ is to the fermenting fluids containing sugar.
In a sense, this is no doubt strictly true: it is impossible to find a
decomposing proteinaceous solution, at any stage, without finding this
form in vast abundance.
But it is well to remember that in nature putrefactive ferments must
go on to an extent rarely imitated or followed in the laboratory. As a
rule, the pabulum in which the saprophytic organisms are provided and
"cultured" is infusions, or extracts of meat carefully filtered, and,
if vegetable matter is used, extracts of fruit, treated with equal
care, and if needful neutralized, are used in a similar way. To these
may be added all the forms of gelatine, employed in films, masses and
so forth.
But in following the process of destructive fermentation as it takes
place in large masses of tissue, animal or vegetable, but far
preferably the former, as they lie in water at a constant temperature
of from 60° to 65° F., it will be seen that the fermentative process
is the work, not of one organism, nor, judging by the standard of our
present knowledge, of one specified class of vegetative forms, but by
organisms which, though related to each other, are in many respects
greatly dissimilar, not only morphologically, but also embryologically,
and even physiologically.
Moreover, although this is a matter that will want most thorough and
efficient inquiry and research to understand properly its conditions,
yet it is sufficiently manifest that these organisms succeed each
other in a curious and even remarkable manner. Each does a part in the
work of fermentative destruction; each aids in splitting up into lower
and lower compounds the elements of which the masses of degrading
tissue are composed; while, apparently, each set in turn does by vital
action, coupled with excretion, (1) take up the substances necessary
for its own growth and multiplication; (2) carry on the fermentative
process; and (3) so change the immediate pabulum as to give rise to
conditions suitable for its immediate successor. Now the point of
special interest is that there is an apparent adaptation in the form,
functions, mode of multiplication, and order of succession in these
fermentative organisms, deserving study and fraught with instruction.
Let it be remembered that the aim of nature in this fermentative
action is not the partial splitting of certain organic compounds, and
their reconstruction in simpler conditions, but the ultimate setting
free, by saprophytic action, of the elements locked up in great masses
of organic tissue--the sending back into nature of the only material
of which future organic structures are to be composed.
I have said that there can be no question whatever that _Bacterium
termo_ is the pioneer of saprophytes. Exclude _B. termo_ (and
therefore with it all its congeners), and you can obtain no
putrefaction. But wherever, in ordinary circumstances, a decomposable
organic mass, say the body of a fish, or a considerable mass of the
flesh of a terrestrial animal, is exposed in water at a temperature of
60° to 65° F., _B. termo_ rapidly appears, and increases with a simply
astounding rapidity. It clothes the tissues like a skin, and diffuses
itself throughout the fluid.
The exact chemical changes it thus effects are not at present clearly
known; but the fermentative action is manifestly concurrent with its
multiplication. It finds its pabulum in the mass it ferments by its
vegetative processes. But it also produces a visible change in the
enveloping fluid, and noxious gases continuously are thrown off.
In the course of a week or more, dependent on the period of the year,
there is, not inevitably, but as a rule, a rapid accession of spiral
forms, such as _Spirillum volutans_, _S. undula_, and similar forms,
often accompanied by _Bacterium lineola_; and the whole interspersed
still with inconceivable multitudes of _B. termo_.
These invest the rotting tissues liked an elastic garment, but are
always in a state of movement. These, again, manifestly further the
destructive ferment, and bring about a softness and flaccidity in the
decomposing tissues, while they without doubt, at the same time, have,
by their vital activity and possible secretions, affected the
condition of the changing organic mass. There can be, so far as my
observations go, no certainty as to when, after this, another form of
organism will present itself; nor, when it does, which of a limited
series it will be. But, in a majority of observed cases, a loosening
of the living investment of bacterial forms takes place, and
simultaneously with this, the access of one or two forms of my
putrefactive monads. They were among the first we worked at; and have
been, by means of recent lenses, among the last revised. Mr. S. Kent
named them _Cercomonas typica_ and _Monas dallingeri_ respectively.
They are both simple oval forms, but the former has a flagellum at
both ends of the longer axis of the body, while the latter has a
single flagellum in front.
The principal difference is in their mode of multiplication by
fission. The former is in every way like a bacterium in its mode of
self-division. It divides, acquiring for each half a flagellum in
division, and then, in its highest vigor, in about four minutes, each
half divides again.
The second form does not divide into two, but into many, and thus
although the whole process is slower, develops with greater rapidity.
But both ultimately multiply--that is, commence new generations--by
the equivalent of a sexual process.
These would average about four times the size of _Bacterium termo_;
and when once they gain a place on and about the putrefying tissues,
their relatively powerful and incessant action, their enormous
multitude, and the manner in which they glide over, under, and beside
each other, as they invest the fermenting mass, is worthy of close
study. It has been the life history of these organisms, and not their
relations as ferment, that has specially occupied my fullest
attention; but it would be in a high degree interesting if we could
discover, or determine, what besides the vegetative or organic
processes of nutrition are being effected by one, or both, of these
organisms on the fast yielding mass. Still more would it be of
interest to discover what, if any, changes were wrought in the
pabulum, or fluid generally. For after some extended observations I
have found that it is only after one or other or both, of these
organisms have performed their part in the destructive ferment, that
subsequent and extremely interesting changes arise.
It is true that in some three or four instances of this saprophytic
destruction of organic tissues, I have observed that, after the strong
bacterial investment, there has arisen, not the two forms just named,
nor either of them, but one or other of the striking forms now called
_Tetramitus rostratus_ and _Polytoma uvella_; but this has been in
relatively few instances. The rule is that _Cercomonas typica_ or its
congener precedes other forms, that not only succeed them in promoting
and carrying to a still further point the putrescence of the
fermenting substance, but appear to be aided in the accomplishment of
this by mechanical means.
By this time the mass of tissue has ceased to cohere. The mass has
largely disintegrated, and there appears among the countless bacterial
and monad forms some one, and sometimes even three forms, that while
they at first swim and gyrate, and glide about the decomposing matter,
which is now much less closely invested by _Cercomonas typica_, or
those organisms that may have acted in its place, they also resort to
an entirely new mode of movement.
One of these forms is _Heteromita rostrata_, which, it will be
remembered, in addition to a front flagellum, has also a long fiber or
flagellum-like appendage that gracefully trails as it swims. At
certain periods of its life they anchor themselves in countless
billions all over the fermenting tissues, and as I have described in
the life history of this form, they coil their anchored fiber, as does
a vorticellan, bringing the body to the level of the point of
anchorage, then shoot out the body with lightning-like rapidity, and
bring it down like a hammer on some point of the decomposition. It
rests here for a second or two, and repeats the process; and this is
taking place by what seems almost like rhythmic movement all over the
rotting tissue. The results are scarcely visible in the mass. But if a
group of these organisms be watched, attached to a small particle of
the fermenting tissue, it will be seen to gradually diminish, and at
length to disappear.
Now, there are at least two other similar forms, one of which,
_Heteromita uncinata_, is similar in action, and the other of which,
_Dallingeria drysdali_, is much more powerful, being possessed of a
double anchor, and springing down upon the decadent mass with
relatively far greater power.
Now, it is under the action of these last forms that in a period
varying from one month to two or three the entire substance of the
organic tissues disappears, and the decomposition has been designated
by me "exhausted"; nothing being left in the vessel but slightly
noxious and pale gray water, charged with carbonic acid, and a fine,
buff colored, impalpable sediment at the bottom.
My purpose is not, by this brief notice, to give an exhaustive, or
even a sufficient account, of the progress of fermentative action, by
means of saprophytic organisms, on great masses of tissue; my
observations have been incidental, but they lead me to the conclusion
that the fermentative process is not only not carried through by what
are called saprophytic bacteria, but that a _series_ of fermentative
organisms arise, which succeed each other, the earlier ones preparing
the pabulum or altering the surrounding medium, so as to render it
highly favorable to a succeeding form. On the other hand, the
succeeding form has a special adaptation for carrying on the
fermentative destruction more efficiently from the period at which it
arises, and thus ultimately of setting free the chemical elements
locked up in dead organic compounds.
That these later organisms are saprophytic, although not bacterial,
there can be no doubt. A set of experiments, recorded by me in the
proceedings of this society some years since, would go far to
establish this (_Monthly Microscopical Journal_, 1876, p. 288). But it
may be readily shown, by extremely simple experiments, that these
forms will set up fermentative decomposition rapidly if introduced in
either a desiccated or living condition, or in the spore state, into
suitable but sterilized pabulum.
Thus while we have specific ferments which bring about definite and
specific results, and while even infusions of proteid substances may
be exhaustively fermented by saprophytic bacteria, the most important
of all ferments, that by which nature's dead organic masses are
removed, is one which there is evidence to show is brought about by
the successive vital activities of a series of adapted organisms,
which are forever at work in every region of the earth.
There is one other matter of some interest and moment on which I would
say a few words. To thoroughly instructed biologists, such words will
be quite needless; but, in a society of this kind, the possibilities
that lie in the use of the instrument are associated with the
contingency of large error, especially in the biology of the minuter
forms of life, unless a well grounded biological knowledge form the
basis of all specific inference, to say nothing of deduction.
I am the more encouraged to speak of the difficulty to which I refer,
because I have reason to know that it presents itself again and again
in the provincial societies of the country, and is often adhered to
with a tenacity worthy of a better cause. I refer to the danger that
always exists, that young or occasional observers are exposed to, amid
the complexities of minute animal and vegetable life, of concluding
that they have come upon absolute evidences of the transformation of
one minute form into another; that in fact they have demonstrated
cases of heterogenesis.
This difficulty is not diminished by the fact that on the shelves of
most microscopical societies there is to be found some sort of
literature written in support of this strange doctrine.
You will pardon me for allusion again to the field of inquiry in which
I have spent so many happy hours. It is, as you know, a region of life
in which we touch, as it were, the very margin of living things. If
nature were capricious anywhere, we might expect to find her so here.
If her methods were in a slovenly or only half determined condition,
we might expect to find it here. But it is not so. Know accurately
what you are doing, use the precautions absolutely essential, and
through years of the closest observation it will be seen that the
vegetative and vital processes generally, of the very simplest and
lowliest life forms, are as much directed and controlled by immutable
laws as the most complex and elevated.
The life cycles, accurately known, of monads repeat themselves as
accurately as those of rotifers or planarians.
And of course, on the very surface of the matter, the question
presents itself to the biologist why it should not be so. The
irrefragable philosophy of modern biology is that the most complex
forms of living creatures have derived their splendid complexity and
adaptations from the slow and majestically progressive variation and
survival from the simpler and the simplest forms. If, then, the
simplest forms of the present and the past were not governed by
accurate and unchanging laws of life, how did the rigid certainties
that manifestly and admittedly govern the more complex and the most
complex come into play?
If our modern philosophy of biology be, as we know it is, true, then
it must be very strong evidence indeed that would lead us to conclude
that the laws seen to be universal break down and cease accurately to
operate where the objects become microscopic, and our knowledge of
them is by no means full, exhaustive, and clear.
Moreover, looked at in the abstract, it is a little difficult to
conceive why there should be more uncertainty about the life processes
of a group of lowly living things than there should be about the
behavior, in reaction, of a given group of molecules.
The triumph of modern knowledge is the certainty, which nothing can
shake, that nature's laws are immutable. The stability of her
processes, the precision of her action, and the universality of her
laws, is the basis of all science, to which biology forms no
exception. Once establish, by clear and unmistakable demonstration,
the life history of an organism, and truly some change must have come
over nature as a whole, if that life history be not the same to-morrow
as to-day; and the same to one observer, in the same conditions, as to
another.
No amount of paradox would induce us to believe that the combining
proportions of hydrogen and oxygen had altered, in a specified
experimenter's hands, in synthetically producing water.
We believe that the melting point of platinum and the freezing point
of mercury are the same as they were a hundred years ago, and as they
will be a hundred years hence.
Now, carefully remember that so far as we can see at all, it must be
so with life. Life inheres in protoplasm; but just as you cannot get
_abstract matter_--that is, matter with no properties or modes of
motion--so you cannot get _abstract_ protoplasm. Every piece of living
protoplasm we see has a history; it is the inheritor of countless
millions of years. Its properties have been determined by its history.
It is the protoplasm of some definite form of life which has inherited
its specific history. It can be no more false to that inheritance than
an atom of oxygen can be false to its properties.
All this, of course, within the lines of the great secular processes
of the Darwinian laws; which, by the way, could not operate at all if
caprice formed any part of the activities of nature.
But let me give a practical instance of how what appears like fact may
override philosophy, if an incident, or even a group of incidents,
_per se_ are to control our judgment.
Eighteen years ago I was paying much attention to vorticellæ. I was
observing with some pertinacity _Vorticella convallaria_; for one of
the calices in a group under observation was in a strange and
semi-encysted state, while the remainder were in full normal activity.
I watched with great interest and care, and have in my folio still the
drawings made at the time. The stalk carrying this individual calyx
fell upon the branch of vegetable matter to which the vorticellan was
attached, and the calyx became perfectly globular; and at length there
emerged from it a small form with which, in this condition, I was
quite unfamiliar; it was small, tortoise-like in form, and crept over
the branch on setæ or hair-like pedicels; but, carefully followed, I
found it soon swam, and at length got the long neck-like appendage of
_Amphileptus anser_!
Here then was the cup or calyx of a definite vorticellan form changing
into (?) an absolutely different infusorian, viz., _Amphileptus
anser_!
Now I simply reported the _fact_ to the Liverpool Microscopical
Society, with no attempt at inference; but two years after I was able
to explain the mystery, for, finding in the same pond both _V.
convallaria_ and _A. anser_, I carefully watched their movements, and
saw the _Amphileptus_ seize and struggle with a calyx of
_convallaria_, and absolutely become encysted upon it, with the
results that I had reported two years before.
And there can be no doubt but this is the key to the cases that come
to us again and again of minute forms suddenly changing into forms
wholly unlike. It is happily among the virtues of the man of science
to "rejoice in the truth," even though it be found at his expense; and
true workers, earnest seekers for nature's methods, in the obscurest
fields of her action, will not murmur that this source of danger to
younger microscopists has been pointed out, or recalled to them.
And now I bid you, as your president, farewell. It has been all
pleasure to me to serve you. It has enlarged my friendships and my
interests, and although my work has linked me with the society for
many years, I have derived much profit from this more organic union
with it; and it is a source of encouragement to me, and will, I am
sure, be to you, that, after having done with simple pleasure what I
could, I am to be succeeded in this place of honor by so distinguished
a student of the phenomena of minute life as Dr. Hudson. I can but
wish him as happy a tenure of office as mine has been.
* * * * *
INQUIRIES REGARDING THE INCUBATOR.
P.H. JACOBS.
Space in the _Rural_ is valuable, and so important a subject as
artificial incubation cannot perhaps be made entirely plain to a
novice in a few articles; but as interested parties have written for
additional information, it may interest others to answer them here.
Among the questions asked are: "Does the incubator described in the
_Rural_ dispense entirely with the use of a lamp, using at intervals a
bucket of water to maintain proper temperature? I fear this will not
be satisfactory unless the incubator is kept in a warm room or
cellar."
All incubators must be kept in a warm location, whether operated by a
lamp or otherwise. The warmer the room or cellar, the less warmth
required to be supplied. Bear in mind that the incubator recommended
has four inches of sawdust surrounding it, and more sawdust would
still be an advantage. The sawdust is not used to protect against the
outside temperature, but to absorb and hold a large amount of heat,
and that is the secret of its success. The directions given were to
first fill the tank with boiling water and allow it to remain for 24
hours. In the meantime the sawdust absorbs the heat, and more boiling
water is then added until the egg-drawer is about 110 or 115 degrees.
By this time there is a quantity of stored heat in the sawdust. The
eggs will cool the drawer to 103. The loss of heat (due to its being
held by the sawdust) will be very slow. All that is needed then is to
supply that which will be lost in 12 hours, and a bucket of boiling
water should keep the heat about correct, if added twice a day, but it
may require more, as some consideration must be given to fluctuations
of the temperature of the atmosphere. The third week of incubation,
owing to animal heat from the embryo chicks, a bucket of boiling water
will sometimes hold temperature for 24 hours. No objection can be
urged against attaching a lamp arrangement, but a lamp is dangerous at
night, while the flame must be regulated according to temperature. The
object of giving the hot water method was to avoid lamps. We have a
large number of them in use (no lamps) here, and they are equal to any
others in results.
With all due respect to some inquirers, the majority of them seem
afraid of the work. Now, there is some work with all incubators. What
is desired is to get rid of the anxiety. I stated that a bucket of
water twice a day would suffice. I trusted to the judgment of the
reader somewhat. Of course, if the heat in the egg drawer is 90
degrees, and the weather cold, it may then take a wash boiler full of
water to get the temperature back to 103 degrees, but when it is at
103 keep it there, even if it occasionally requires two buckets of
boiling water. To judge of what may be required, let us suppose the
operator looks at the thermometer in the morning, and it is exactly
103 degrees. He estimates that it will lose a little by night, and
draws off half a bucket of water. At night he finds it at 102. Knowing
that it is on what we term "the down grade," he applies a bucket and a
half (always allowing for the night being colder than the day). As
stated, the sawdust will not allow the drawer to become too cold, as
it gives off heat to the drawer. And, as the sawdust absorbs, it is
not easy to have the heat too high. One need not even look at the
drawer until the proper times. No watching--the incubator regulates
itself. If a lamp is used, too much heat may accumulate. The flame
must be occasionally turned up or down, and the operator must remain
at home and watch it, while during the third week he will easily cook
his eggs.
The incubator can be made at home for so small a sum (about $5 for the
tank, $1 for faucet, etc., with 116 feet of lumber) that it will cost
but little to try it. A piece of glass can be placed in front of the
egg drawer, if preferred. If the heat goes down to 90, or rises at
times to 105, no harm is done. But it works well, and hatches, the
proof being that hundreds are in use. I did not give the plan as a
theory or an experiment. They are in practical use here, and work
alongside of the more expensive ones, and have been in use for four
years. To use a lamp attachment, all that is necessary is to have a
No. 2 burner lamp with a riveted sheet-iron chimney, the chimney
fitting over the flame, like an ordinary globe, and extending the
chimney (using an elbow) through the tank from the rear, ending in
front. It should be soldered at the tank. The heat from the lamp will
then pass through the chimney and consequently warm the surrounding
water.--_Rural New-Yorker._
[For description and illustrations of this incubator see SUPPLEMENT,
No. 630.]
* * * * *
THE PEAK OF TENERIFFE.
The Hon. Ralph Abercromby made a trip to the island of Teneriffe in
October, 1887, for the purpose of making some electrical and
meteorological observations, and now gives some of the results which
he obtained, which may be summarized as follows: The electrical
condition of the peak of Teneriffe was found to be the same as in
every other part of the world. The potential was moderately positive,
from 100 to 150 volts, at 5 ft. 5 in. from the ground, even at
considerable altitudes; but the tension rose to 549 volts on the
summit of the peak, 12,200 ft., and to 247 volts on the top of the
rock of Gayga, 7,100 feet. A large number of halos were seen
associated with local showers and cloud masses. The necessary ice dust
appeared to be formed by rising currents. The shadow of the peak was
seen projected against the sky at sunset. The idea of a southwest
current flowing directly over the northeast trade was found to be
erroneous. There was always a regular vertical succession of air
currents in intermediate directions at different levels from the
surface upward, so that the air was always circulating on a
complicated screw system.
* * * * *
ESTRADE'S HIGH SPEED LOCOMOTIVE.
We illustrate a very remarkable locomotive, which has been constructed
from the designs of M. Estrade, a French engineer. This engine was
exhibited last year in Paris. Although the engine was built, M.
Estrade could not persuade any railway company to try it for him, and
finally he applied to the French government, who have at last
sanctioned the carrying out of experiments with it on one of the state
railway lines. The engine is in all respects so opposed to English
ideas that we have hitherto said nothing about it. As, however, it is
going to be tried, an importance is given to it which it did not
possess before; and, as a mechanical curiosity, we think it is worth
the consideration of our readers.
In order that we may do M. Estrade no injustice, we reproduce here in
a condensed form, and in English, the arguments in its favor contained
in a paper written by M. Max de Nansouty, C.E., who brought M.
Estrade's views before the French Institution of Civil Engineers, on
May 21, 1886. M. Nansouty's paper has been prepared with much care,
and contains a great deal of useful data quite apart from the Estrade
engine. The paper in question is entitled "_Memoire relatif au
Materiel Roulant a Grand Vitesse_," D.M. Estrade.
About thirty years ago, M. Estrade, formerly pupil of the Polytechnic
School, invented rolling stock for high speed under especial
conditions, and capable of leading to important results, more
especially with regard to speed. Following step by step the progress
made in the construction of railway stock, the inventor, from time to
time, modified and improved his original plan, and finally, in 1884,
arrived at the conception of a system entirely new in its fundamental
principles and in its execution. A description of this system is the
object of the memoir.
The great number of types of locomotives and carriages now met with in
France, England, and the United States renders it difficult to combine
their advantages, as M. Estrade proposed to do, in a system responding
to the requirements of the constructor. His principal object, however,
has been to construct, under specially favorable conditions, a
locomotive, tender, and rolling stock adapted to each other, so as to
establish a perfect accord between these organs when in motion. It is,
in fact, a complete train, and not, as sometimes supposed, a
locomotive only, of an especial type, which has been the object he set
before him. Before entering into other considerations, we shall first
give a description of the stock proposed by M. Estrade. The idea of
the invention consists in the use of coupled wheels of large diameter
and in the adoption of a new system of double suspension.
The locomotive and tender we illustrate were constructed by MM. Boulet
& Co. The locomotive is carried on six driving wheels, 8 feet 3 inches
in diameter. The total weight of the engine is thus utilized for
adhesion. The accompanying table gives the principal dimensions:
TABLE I.
+---------------------------------------+
| | ft. in. |
+-----------------------+---------------+
|Total length of engine.| 32 8 |
+-----------------------+---------------+
|Width between frames. | 4 1 |
+-----------------------+---------------+
|Wheel base, total. | 16 9 |
+-----------------------+---------------+
|Diameter of cylinder. | 1 6½ |
+-----------------------+---------------+
|Length of stroke. | 2 3½ |
+-----------------------+---------------+
|Grate surface. | 25 sq. feet. |
+-----------------------+---------------+
|Total heating surface. | 1,400 sq. ft. |
+-----------------------+---------------+
|Weight empty. | 38 tons. |
+-----------------------+---------------+
|Weight full. | 42 tons. |
+---------------------------------------+
The high speeds--77 to 80 miles an hour--in view of which this stock
has been constructed have, it will be seen, caused the elements
relative to the capacity of the boiler and the heating surfaces to be
developed as much as possible. It is in this, in fact, that one of the
great difficulties of the problem lies, the practical limit of
stability being fixed by the diameter of the driving wheels. Speed can
only be obtained by an expenditure of steam which soon becomes such as
rapidly to exhaust the engine unless the heating surface is very
large.
The tender, also fitted with wheels of 8 ft. 3 in. in diameter, offers
no particular feature; it is simply arranged so as to carry the
greatest quantity of coal and water.
M. Estrade has also designed carriages. One has been constructed by
MM. Reynaud, Bechade, Gire & Co., which has very few points in common
with those in general use. Independently of the division of the
compartments into two stories, wheels 8 ft. 3 in. in diameter are
employed, and the double system of suspension adopted. Two axles, 16
ft. apart, support, by means of plate springs, an iron framing running
from end to end over the whole length, its extremities being curved
toward the ground. Each frame carries in its turn three other plate
springs, to which the body is suspended by means of iron tie-rods
serving to support it. This is then a double suspension, which at once
appears to be very superior to the systems adopted up to the present
time. The great diameter of the wheels has necessitated the division
into two stories. The lower story is formed of three equal parts,
lengthened toward the axles by narrow compartments, which can be
utilized for luggage or converted into lavatories, etc. Above is one
single compartment with a central passage, which is reached by
staircases at the end. All the vehicles of the same train are to be
united at this level by jointed platforms furnished with hand rails.
It is sufficient to point out the general disposition, without
entering into details which do not affect the system, and which must
vary for the different classes and according to the requirements of
the service.
[Illustration: M. ESTRADE'S HIGH SPEED LOCOMOTIVE.]
M. Nansouty draws a comparison between the diameters of the driving
wheels and cylinders of the principal locomotives now in use and those
of the Estrade engine as set forth in the following table. We only
give the figures for coupled engines:
TABLE II.
+--------------------+------------------+-----------+-------------+
| | Diameter of | Size of | |
| | driving wheels. | cylinder. | Position of |
| | ft. in. | in. in. | cylinder. |
+--------------------+------------------+-----------+-------------+
|Great Eastern | 7 0 | 18 × 24 | inside |
+--------------------+------------------+-----------+-------------+
|South-Eastern | 7 0 | 19 × 26 | " |
+--------------------+------------------+-----------+-------------+
|Glasgow and | | | |
|Southwestern | 6 1 | 18 × 26 | " |
+--------------------+------------------+-----------+-------------+
|Midland, 1884 | 7 0 | 19 × 26 | " |
+--------------------+------------------+-----------+-------------+
|North-Eastern | 7 0 | 17½ × 24 | " |
+--------------------+------------------+-----------+-------------+
|London and | | | |
|North-Western | 6 6 | 17 × 24 | " |
+--------------------+------------------+-----------+-------------+
|Lancashire and | | | |
|Yorkshire | 6 0 | 17½ × 26 | " |
+--------------------+------------------+-----------+-------------+
|North British | 6 4 | 17 × 24 | " |
+--------------------+------------------+-----------+-------------+
|Nord | 7 0 | 17 × 24 | " |
+--------------------+------------------+-----------+-------------+
|Paris-Orleans, 1884 | 6 8 | 17 × 23½ | outside. |
+--------------------+------------------+-----------+-------------+
|Ouest | 6 0 | 17¼ × 25½| " |
+-----------------------------------------------------------------+
This table, the examination of which will be found very instructive,
shows that there are already in use: For locomotives with single
drivers, diameters of 9 ft., 8 ft. 1 in., and 8 ft.; (2) for
locomotives with four coupled wheels, diameters 6 ft. to 7 ft. There
is therefore an important difference between the diameters of the
coupled wheels of 7 ft. and those of 8 ft. 3 in., as conceived by M.
Estrade. However, the transition is not illogically sudden, and if the
conception is a bold one, "it cannot," says M. Nansouty, "on the other
hand, be qualified as rash."
He goes on to consider, in the first place: Especial types of
uncoupled wheels, the diameters of which form useful samples for our
present case. The engines of the Bristol and Exeter line are express
tender engines, adopted on the English lines in 1853, some specimens
of which are still in use.[1] These engines have ten wheels, the
single drivers in the center, 9 ft. in diameter, and a four-wheeled
bogie at each end. The driving wheels have no flanges. The bogie
wheels are 4 ft. in diameter. The cylinders have a diameter of 16½ in.
and a piston stroke of 24 in. The boiler contains 180 tubes, and the
total weight of the engine is 42 tons. These locomotives, constructed
for 7 ft. gauge, have attained a speed of seventy-seven miles per
hour.
[Footnote 1: M. Nansouty is mistaken. None of the Bristol and
Exeter tank engines with. 9 ft. wheels are in use, so far as we
know. ED. E.]
The single driver locomotives of the Great Northern are powerful
engines in current use in England. The driving wheels carry 17 tons,
the heating surface is 1,160 square feet, the diameters of the
cylinders 18 in., and that of the driving wheels 8 ft. 1 in. We have
here, then, a diameter very near to that adopted by M. Estrade, and
which, together with the previous example, forms a precedent of great
interest. The locomotive of the Great Northern has a leading
four-wheeled bogie, which considerably increases the steadiness of the
engine, and counterbalances the disturbing effect of outside
cylinders. Acting on the same principles which have animated M.
Estrade, that is to say, with the aim of reducing the retarding
effects of rolling friction, the constructor of the locomotive of the
Great Northern has considerably increased the diameter of the wheels
of the bogie. In this engine all the bearing are inside, while the
cylinders are outside and horizontal. The tender has six wheels, also
of large dimensions. It is capable of containing three tons and a half
of coal and about 3,000 gallons of water. This type of engine is now
in current and daily use in England.
M. Nansouty next considers the broad gauge Great Western engines with
8 ft. driving wheels. The diameters of their wheels approach those of
M. Estrade, and exceed considerably in size any lately proposed. M.
Nansouty dwells especially upon the boiler power of the Great Western
railway, because one of the objections made to M. Estrade's locomotive
by the learned societies has been the difficulty of supplying boiler
power enough for high speeds contemplated; and he deals at
considerable length with a large number of English engines of maximum
power, the dimensions and performance of which are too well known to
our readers to need reproduction here.
Aware that a prominent weak point in M. Estrade's design is that, no
matter what size we make cylinders and wheels, we have ultimately to
depend on the boiler for power, M. Nansouty argues that M. Estrade
having provided more surface than is to be found in any other engine,
must be successful. But the total heating surface in the engine, which
we illustrate, is but 1,400 square feet, while that of the Great
Western engines, on which he lays such stress, is 2,300 square feet,
and the table which he gives of the heating surface of various English
engines really means very little. It is quite true that there are no
engines working in England with much over 1,500 square feet of
surface, except those on the broad gauge, but it does not follow that
because they manage to make an average of 53 miles an hour that an
addition of 500 square feet would enable them to run at a speed higher
by 20 miles an hour. There are engines in France, however, which have
as much as 1,600 square feet, as, for example, on the Paris-Orleans
line, but we have never heard that these engines attain a speed of 80
miles an hour.
Leaving the question of boiler power, M. Nansouty goes on to consider
the question of adhesion. About this he says:
Is the locomotive proposed by M. Estrade under abnormal conditions as
to weight and adhesion? This appears to have been doubted, especially
taking into consideration its height and elegant appearance. We shall
again reply here by figures, while remarking that the adhesion of
locomotives increases with the speed, according to laws still unknown
or imperfectly understood, and that consequently for extreme speeds,
ignorance of the value of the coefficiency of adhesion f in the
formula
d 2 I
fP = 0.65 p ------- - R
D
renders it impossible to pronounce upon it before the trials earnestly
and justly demanded by the author of this new system. In present
practice f = 1/7 is admitted. M. Nansouty gives in a table a
_resume_ of the experience on this subject, and goes on:
"The English engineers, as will be seen, make a single axle support
more than 17 tons. In France the maximum weight admitted is 14 tons,
and the constructor of the Estrade locomotive has kept a little below
this figure. The question of total weight appears to be secondary in a
great measure, for, taking the models with uncoupled wheels, the
English engines for great speed have on an average, for a smaller
total weight, an adhesion equal to that of the French locomotives. The
P.L.M. type of engine, which has eight wheels, four of which are
coupled, throws only 28.6 tons upon the latter, being 58 per cent. of
the total weight. On the other hand, that of the English Great Eastern
throws 68 per cent. of the total weight on the driving wheels.
Numerous other examples could be cited. We cannot, we repeat, give an
opinion rashly as to the calculation of adhesion for the high speed
Estrade locomotive before complete trials have taken place which will
enable us to judge of the particular coefficients for this entirely
new case."
M. Nansouty then goes on to consider the question of curves, and says:
"It has been asked, not without reason, notably by the Institution of
Civil Engineers of Paris, whether peculiar difficulties will not be
met with by M. Estrade's locomotive--with its three axles and large
coupled wheels--in getting round curves. We have seen in the preceding
tables that the driving wheels of the English locomotives with
independent wheels are as much as 8 ft. in diameter. The driving
wheels of the English locomotives with four coupled wheels are 7 ft.
in diameter. M. Estrade's locomotive has certainly six coupled wheels
with diameters never before tried, but these six coupled wheels
constitute the whole rolling length, while in the above engines a
leading axle or a bogie must be taken into account, independent, it is
true, but which must not be lost sight of, and which will in a great
measure equalize the difficulties of passing over the curves.
"Is it opposed to absolute security to attack the line with driving
wheels? This generally admitted principle appears to rest rather on
theoretic considerations than on the results of actual experience. M.
Estrade, besides, sets in opposition to the disadvantages of attacking
the rails with driving wheels those which ensue from the use of wheels
of small diameter as liable to more wear and tear. We should further
note with particular care that the leading axle of this locomotive has
a certain transverse play, also that it is a driving axle. This
disposition is judicious and in accordance with the best known
principles."
A careful perusal of M. Nansouty's memoir leaves us in much doubt as
to what M. Estrade's views are based on. So far as we understand him,
he seems to have worked on the theory that by the use of very large
wheels the rolling resistance of a train can be greatly diminished. On
this point, however, there is not a scrap of evidence derived from
railway practice to prove that any great advantage can be gained by
augmenting the diameters of wheels. In the next place, he is afraid
that he will not have adhesion enough to work up all his boiler power,
and, consequently, he couples his wheels, thereby greatly augmenting
the resistance of the engine. He forgets that large coupled wheels
were tried years ago on the Great Western Railway, and did not answer.
A single pair of drivers 8 ft. 3 in. in diameter would suffice to work
up all the power M. Estrade's boiler could supply at sixty miles an
hour, much less eighty miles an hour. On the London and Brighton line
Mr. Stroudley uses with success coupled leading wheels of large
diameter on his express engines, and we imagine that M. Estrade's
engine will get round corners safely enough, but it is not the right
kind of machine for eighty miles an hour, and so he will find out as
soon as a trial is made. The experiment is, however, a notable
experiment, and M. Estrade has our best wishes for his success.--_The
Engineer._
* * * * *
CONCRETE.[1]
[Footnote 1: Read July 5, 1887, before the Western Society of
Engineers.]
By JOHN LUNDIE.
The subject of cement and concrete has been so well treated of in
engineering literature, that to give an extended paper on the subject
would be but the collection and reiteration of platitudes familiar to
every engineer who has been engaged on foundation works of any
magnitude. It shall therefore be the object of this communication to
place before the society several notes, stated briefly and to the
point, rather as a basis for discussion than as an attempt at an
exhaustive treatment of the subject.
Concrete is simply a low grade of masonry. It is a comparatively
simple matter to trace the line of continuity from heavy squared
ashlar blocks down through coursed and random rubble, to grouted
indiscriminate rubble, and finally to concrete. Improvements in the
manufacture of hydraulic cements have given an impetus to the use of
concrete, but its use is by no means of recent date. It is no uncommon
thing in the taking down of heavy walls several centuries old to find
that the method of building was to carry up face and back with rubble
and stiff mortar, and to fill the interior with bowlders and gravel,
the interstices of which were filled by grouting--the whole mass
becoming virtually a monolith. Modern quick-setting cement
accomplishes this object within a time consistent with the
requirements of modern engineering works; the formation of a
monolithic mass within a reasonable time and with materials requiring
as little handling as possible being the desideratum.
The materials of concrete as used at present are cement, sand, gravel,
broken stone, and, of course, water. It is, perhaps, unnecessary to
say that one of the primary requirements in materials is that they
should be clean. Stone should be angular, gravel well washed, sand
coarse and sharp, cement fine and possessing a fair proportion of the
requirements laid down in the orthodox specification. The addition of
lime water, saccharated or otherwise, has been suggested as an
improvement over water pure and simple, but no satisfactory
experiments are on record justifying the addition of lime water.
Regarding the mixing of cement and lime with saccharated water, the
writer made some experiments several months ago by mixing neat cement
and lime with pure water and with saccharated water, with the result
that the sugar proved positively detrimental to the cement, while it
increased the tenacity of briquettes of lime.
Stone which will pass a 2 inch is usually specified for ordinary
concrete. It will be found that stone broken to this limit of size has
fifty per cent. of its bulk voids. This space must be filled by mortar
or preferably by gravel and mortar. If the mixing of concrete is
perfect, the proportion of stone, by bulk, to other materials should
be two to one. A percentage excess of other materials is, however,
usually allowed to compensate for imperfection in mixing. While an
excess of good mortar is not detrimental to concrete (as it will
harden in course of time to equal the stone), still on the score of
economy it is advisable to use gravel or a finer grade of stone in
addition to the 2 inch ring stone to fill the interstices--gravel is
cheaper than cement. The statement that excess in stone will give body
to concrete is a fallacy hardly worth contradicting. In short, the
proportion of material should be so graded that each particle of sand
should have its jacket of cement, necessitating the cement being finer
than the sand (this forms the mortar); then each pebble and stone
should have its jacket of mortar. The smaller the interstices between
the gravel and stones, the better. The quantity of water necessary to
make good concrete is a sorely debated question. The quantity
necessary depends on various considerations, and will probably be
different for what appears to be the same proportion of materials. It
is a well known fact that brick mortar is made very soft, and bricks
are often wet before being laid, while a very hard stone is usually
set with very stiff mortar. So in concrete the amount of water
necessarily depends, to a great extent, on the porosity or dryness of
the stone and other material used. But as to using a larger or smaller
quantity of water with given materials, as a matter of observation it
will be found that the water should only be limited by its effect in
washing away mortar from the stone. Where can better concrete be found
than that which has set under water? A certain definite amount of
water is necessary and sufficient to hydrate the cement; less than
that amount will be detrimental, while an excess can do no harm,
provided, as before mentioned, that it does not wash the mortar from
the stone. Again, dry concrete is apt to be very porous, which in
certain positions is a very grave objection to it--this, not only from
the fact of its porosity, but from the liability to disintegration
from water freezing in the crevices.
Concrete, when ready to be placed in position, should be of the
consistency of a pulpy mass which will settle into place by its own
weight, every crevice being naturally filled. Pounding dry concrete is
apt to break adjacent work, which will never again set properly. There
should be no other object in pounding concrete than to assist it to
settle into the place it is intended to fill. This is one of the evils
concomitant with imperfection of mixing. The greater perfection of
mixing attained, the nearer we get to the ideal monolith. The less
handling concrete has after being mixed, the better. Immediately after
the mass is mixed setting commences; therefore the sooner it is in
position, the more perfect will be the hardened mass; and, on the
other hand, the more it is handled, the more is the process
interrupted and in like degree is the finished mass deteriorated. A
low drop will be found the best method of placing a batch in position.
Too much of a drop scatters the material and undoes the work of
thorough mixing. Let the mass drop and then let it alone. If of proper
temper, it will find its own place with very little trimming. Care
should be taken to wet adjacent porous material, or the wooden form
into which concrete is being placed; otherwise the water may be
extracted from the concrete, to its detriment.
It has been found on removing boxing that the portion adjacent to the
wood was frequently friable and of poor quality, owing to the fact
just stated. It is usual to face or plaster concrete work after
removing the boxing. On breakwater work, where the writer was engaged,
the wall was faced with cement and flint grit, and this was found to
form a particularly hard and lasting protection to the face of the
work.
Batches of concrete should be placed in position as if they were
stones in block masonry, as the union of one day's work with a
previous is not by any means so perfect as where one batch is placed
in contact with another which has not yet set. A slope cannot be added
to with the same degree of perfection that one horizontal layer can be
placed on another; consequently, where work must necessarily be
interrupted, it should be stepped, and not sloped off.
Experience in concrete work has shown that its true place is in heavy
foundations, retaining walls, and such like, and then perfectly
independent of other material. Arches, thin walls, and such like are
very questionable structures in continuous concrete, and are on record
rather as failures than otherwise. This may to a certain degree be due
to the high coefficient of expansion Portland cement concrete has by
heat. This was found by Cunningham to be 0.000005 of its bulk for one
degree Fahrenheit. It is a matter which any intelligent observer may
remark, the invariable breakage of continuous concrete sidewalks,
while those made in small sections remain good. This may be traced to
expansion and contraction by heat, together with friction on the lower
side.
In foundations, according to the same authority above quoted, properly
made Portland cement concrete may be trusted with a safe load of 25
tons per square foot.
In large masses concrete should be worked continuously, while in small
masses it should be moulded in small sections, which should be
independent of each other and simply form artificial stones.
The facility with which concrete can be used in founding under water
renders it particularly suitable for subaqueous structures. The method
of dropping it from hopper barges in masses of 100 tons at a time,
inclosed in a bag of coarse stuff, has been successfully employed by
Dyce Cay and others. This can be carried on till the concrete appears
above water, when the ordinary method of boxing can be employed to
complete the work. This method was employed in the north pier
breakwater at Aberdeen, the breakwater being founded on the sand, with
a very broad base. The advantage of bags is apparent in the leveling
off of an uneven foundation. In breakwater works on the Tay, in
Scotland, where the writer was engaged, large blocks perforated
vertically were employed. These were constructed below high water
mark, and an air tight cover placed over them. They were lifted by
pontoons as the tide rose, and conveyed to and deposited in place, the
hollows being filled with air, serving to give buoyancy to the mass.
After placing in position the vertical hollows were filled with
concrete, so binding the whole together--they being placed vertically
over each other.
As mentioned before, continuous stretches of concrete in small
sections should be guarded against, owing to expansion by heat; but
the fact of a few cracks appearing in heavy masses of concrete should
not cause apprehension. These occur from unequal settlement and other
causes. They should continue to be carefully grouted and faced until
settlement is complete.
The use of concrete is becoming more and more general for foundation
works. The desideratum hitherto has been a perfect and at the same
time an economical mixer. Concrete can be mixed by hand and the
materials well incorporated, but this is an expensive and man-killing
method, as the handling of the wet mass by the shovel is extremely
hard work, besides which the slowness of the method allows part of a
large batch to set before the other is mixed, so that small batches,
with attendant extra handling, are necessary to make a good job.
Mixers with a multiplicity of knives to toss the material have been
used, but with little economical success. Of simple conveyers, such as
a worm screw, little need be said; they are not mixers, and it seems a
positive waste of time to pass material through a machine when it
comes out in little better shape than it is put in. A box of the shape
of a barrel has been used, it being trunnioned at the sides. The
objection to this is that the material is thrown from side to side as
a mass, there being a waste of energy in throwing about the material
in mass without accomplishing an equivalent amount of mixing. Then a
rectangular box has been used, trunnioned at opposite corners; but
here the grave objection is that the concrete collects in the corners,
and after a few turns it requires cleaning out, the material so
sticking in the corners that it gets clogged up and ceases to mix.
The writer has just protected by letters patent a machine, in devising
which the following objects were borne in mind:
1st. That every motion of the machine should do some useful work.
Hitherto box or barrel mixers have gone on the principle of
throwing the material about indiscriminately, expecting that
somehow or other it would get mixed.
2d. That the sticking of the material anywhere within the mixer
should be obviated.
3d. That an easy discharge should be obtained.
4th. That the water should be introduced while the mixer
revolves.
With these desiderata in view, a box was designed which in half a turn
gathers the material, then spreads it, and throws it from one side to
the other at the same time that water is being introduced through a
hollow trunnion.
It is also so constructed that all the sides slope steeply toward the
discharge, and there is not a rectangular or acute angle within the
box. A machine has now been worked steadily for several weeks, putting
in the concrete in the foundations of the new Jackson Street bridge in
this city, by General Fitz-Simons. The result exceeds expectations.
The concrete is perfectly mixed, the discharge is simple, complete and
effective, and at the same time the cost of labor in mixing and
placing in position is lessened by 50 per cent. as compared with any
known to have been put in under similar circumstances.--_Jour.
Association of Engineering Societies._
* * * * *
MACHINE DESIGNING.[1]
[Footnote 1: A lecture delivered before the Franklin Institute,
Philadelphia, Monday, Jan. 30, 1888. From the journal of the
Institute.]
By JOHN E. SWEET.
"Carrying coals to Newcastle," the oft quoted comparison, fittingly
indicates the position I place myself in when attempting to address
members of this Institute on the subject of machine designing.
Philadelphia, the birthplace of the great and nearly all the good work
in this, the noblest of all industrial arts, needs no help or praise
at my hands, but I hope her sons may be prevailed upon to do in their
right way what I shall try to do roughly--that is, formulate some
rules or establish principles by which we, who are not endowed with
genius, may so gauge our work as to avoid doing that which is truly
bad. No great author was ever made by studying grammar, rhetoric,
language, history, or by imitating some other author, however great.
Neither has there ever been any great poet or artist produced by
training. But there are many writers who are not great authors, many
rhymsters who are not poets, and many painters who are not artists;
and while training will not make great men of them, it will help them
to avoid doing that which is absolutely bad, and so may it not be with
machine designing? If there are among you some who have a genius for
it, what I shall have to say will do you no good, for genius needs no
rules, no laws, no help, no training, and the sooner you let what I
have to say pass from your minds, the better. Rules only hamper the
man of genius; but for us, who either from choice or necessity work
away at machine designing without the gift, cannot some simple ruling
facts be determined and rules formulated or principles laid down by
which we can determine what is really good, and what bad? One of the
most important and one of the first things in the construction of a
building is the foundation, and the laws which govern its construction
can be stated in a breath, and ought to be understood by every one.
Assuming the ground upon which a building is to be built to be of
uniform density, _the width_ of the foundation should be in proportion
to the load, the foundation should taper equally on each side, and the
center of the foundation should be under the center of pressure. In
other words, it is as fatal to success to have too much foundation
under the light load as it is too little under a heavy one.
Cannot we analyze causes and effects, cost and requirements, so as to
formulate some simple laws similar to the above by which we shall be
able to determine what is a good and what a bad arrangement of
machinery, foundation, framing or supports? A vast amount of work is
expended to make machines true, and the machines, or a large majority
of them, are expected to produce true work of some kind in turn. Then,
if this be admitted, cannot the following law be established, that
every machine should be so designed and constructed that when once
made true it will so remain, regardless of wear and all external
influences to which it is liable to be subjected? One tool maker says
that it is right, and another that it cannot be done. No matter
whether it can or cannot, is it not the thing wanted, and if so, is it
not an object worth striving for? One tool maker says that all machine
tools, engines, and machinery should set on solid stone foundations.
Should they?
They do not always, for in substantial Philadelphia some machine tools
used by machine builders stand upon second floors, or, perhaps, higher
up. And of these machine tools none, or few at least, except those
mounted upon a single pedestal, are free from detrimental torsion
where the floor upon which they rest is distorted by unequal loading.
But, to first consider those of such magnitude as to render it
absolutely necessary to erect them--not rest them--on masonry, is due
consideration always taken to arrange an unequal foundation to support
the unequal loads?--and they cannot be expected to remain true if not.
When one has the good fortune to have a machine to design of such
extent that the masonry becomes the main part of it, what part of the
glory does he give to the mason? Is the masonry part of it always
satisfactory, and is not this resorting to the mason for a frame
rather than a support adopted on smaller machines than is necessary?
Is it necessary even in a planing machine of forty feet length of bed
and a thirty foot table? Could not the bed be cast in three pieces,
the center a rectangular box, 5 or 6 or 7 feet square, 20 feet long,
with internal end flanges, ways planed on its upper surface, and ends
squared off, a monster, perhaps, but if our civil engineers wanted
such a casting for a bridge, they'd get it. Add to this central
section two bevel pieces of half the length, and set the whole down
through the floor where your masonry would have been and rest the
whole on two cross walls, and you would have a structure that if once
made true would remain so regardless of external influences. Cost?
Yes; and so do Frodsham watches--more than "Waterbury."
It may be claimed, in fact, I have seen lathes resting on six and
eight feet, engines on ten, and a planing machine on a dozen. Do they
remain true? Sometimes they do, and many times they do not. Is the
principle right? Not when it can be avoided; and when it cannot be
avoided, the true principle of foundation building should be
employed.... A strange example of depending on the stone foundation
for not simply support, but to resist strain, may be found in the
machines used for beveling the edges of boiler plate. Not so
particularly strange that the first one might have, like Topsy,
"growed," but strange because each builder copies the original. You
will remember it, a complete machine set upon a stone foundation, to
straighten and hold a plate, and another complete machine set down by
the side of it and bolted to the same stone to plane off the edge; a
lot of wasted material and a lot of wasted genius, it always seems to
me. Going around Robin Hood's barn is the old comparison. Why not hook
the tool carriage on the side of the clamping structure, and thus
dispense with one of the frames altogether?
Many of the modern builders of what Chordal calls the hyphen Corliss
engine claim to have made a great advance by putting a post under the
center of the frame, but whether in acknowledgment that the frame
would be likely to go down or the stonework come up I could never make
out. What I should fear would be that the stone would come up and take
the frame with it. Every brick mason knows better than to bed mortar
under the center of a window sill; and this putting a prop under the
center of an engine girder seems a parallel case. They say Mr. Corliss
would have done the same thing if he had thought of it. I do not
believe it. If Mr. Corliss had found his frames too weak, he would
soon have found a way to make them stronger.
John Richards, once a resident of this city, and likely the best
designer of wood-working machinery this country, if not the world,
ever saw, pointed out in some of his letters the true form for
constructing machine framing, and in a way that it had never been
forced on my mind before. As dozens, yes, hundreds, of new designs
have been brought out by machine tool makers and engine builders since
John Richards made a convert of me, without any one else, so far as I
know, having applied the principle in its broadest sense, I hope to
present the case to you in a material form, in the hope that it may be
more thoroughly appreciated.
The usual form of lathe and planer beds or frames is two side plates
and a lot of cross girts; their duty is to guide the carriages or
tables in straight lines and carry loads resisting bending and
torsional strains. If a designer desires to make his lathe frame
stronger than the other fellows, he thinks, if he thinks at all, that
he will put in more iron, rather than, as he ought to think, How shall
I distribute the iron so it will do the most good?
In illustration of this peculiar way of doing things, which is not
wholly confined to machine designers, I should like to relate a story,
and as I had to carry the large end of the joke, it may do for me to
tell it.
While occupying a prominent position, and yet compelled to carry my
dinner, my wife thought the common dinner pail, with which you are
probably familiar (by sight, of course), was not quite the thing for a
professor (even by brevet) to be seen carrying through the streets. So
she interviewed the tinsmith to see if he could not get up something a
little more tony than the regulation fifty-cent sort. Oh, yes; he
could do that very nicely. How much would the best one he could make
cost? Well, if she could stand the racket, he could make one worth a
dollar. She thought she could, and the pail was ordered, made, and
delivered with pride. Perhaps you can guess the result. A facsimile of
the original, only twice the size.
Now, this is a very fair illustration of the fallacy of making things
stronger by simply adding iron. To illustrate what I think a much
better way, I have had made these crude models (see Fig. 1), for the
full force of which, as I said before, I am indebted to John Richards;
and I would here add that the mechanic who has never learned anything
from John Richards is either a very good or very poor one, or has
never read what John Richards has written or heard what he has had to
say.
Three models, as shown in Fig. 1, were exhibited; all were of the same
general dimensions and containing the same amount of material. The one
made on the box principle, c, proved to be fifty per cent. stiffer
in a vertical direction than either a or b, from twenty to fifty
times stiffer sidewise, and thirteen times more rigid against torsion
than either of the others.
However strong a frame may be, its own weight and the weight of the
work upon it tends to spring it unless evenly distributed, and to
twist it unless evenly proportioned. For all small machines the single
post obviates all trouble, but for machine tools of from twice to a
half dozen times their own length the single post is not available.
Four legs are used for machines up to ten feet or so, and above that
legs various and then solid masonry. If the four legs were always set
upon solid masonry, and leveled perfectly when set, no question could
be raised against the usual arrangement, unless it be this: Ought they
not to be set nearly one-fourth the way from the end of the bed? or to
put it in another form: Will not the bed of an iron planing machine
twelve feet in length be equally as well supported by four legs if
each pair is set three feet from the ends--that is, six feet apart--as
by six legs, two pairs at the ends and one in the center, and the
pairs six feet apart? there being six feet of unsupported bed in
either case, with this advantage in favor of the four over the six,
settling of the foundation would not bend the bed.
It is not likely that one-half of the four-legged machine tools used
in this country are resting upon stable foundations, nor that they
ever will be; and while this is a fact, it must also remain a fact
that they should be built so as to do their best on an unstable one.
Any one of the thousand iron planing machines of the country, if put
in good condition and set upon the ordinary wood floors, may be made
to plane work winding in either direction by shifting a moving load of
a few hundred pounds on the floor from one corner of the machine to
the other, and the ways of the ordinary turning lathe may be more
easily distorted still. Machine tool builders do not believe this,
simply because they have not tried it. That is, I suppose this must be
so, for the proof is so positive, and the remedy so simple, that it
does not seem possible they can know the fact and overlook it. The
remedy in the case of the planer is to rest the structure on the two
housings at the rear end and on a pair of legs about one-fourth of the
way back from the front, pivoted to the bed on a single bolt as near
the top as possible.
[Illustration: a, b, c, Fig. 1, illustrate the models shown by
Mr. Sweet, which represented three forms of lathe and planer
construction. The box form, c, proved to be fifty per cent. stronger
in its vertical direction than either a or b, fifty times stronger
sideways than a and twenty times stronger than b, and more than
thirteen times stronger than either when subject to torsional strain.
a, Fig. 2, represents an ordinary pinion tooth, and b shows one of
the same size strengthened by cutting put metal at the root; c and
d were models showing the same width of teeth extended to six times
the length, showing what would be their character if considered as
springs. ]
A similar arrangement applies to the lathe and machine tools of that
character--that is, machines of considerable length in proportion to
their width, and with beds made sufficiently strong within themselves
to resist all bending and torsional strains, fill the requirements so
far as all except wear is concerned. That is, if the frames are once
made true, they will remain so, regardless of all external influences
that can be reasonably anticipated.
Among wood-working machines there are many that cannot be built on the
single rectangular box plan--rested on three points of support.
Fortunately, the requirements are not such as demand absolute straight
and flat work, because in part from the fact that the material dealt
with will not remain straight and flat even if once made so, and in
the design of wood-working machinery it is of more importance to so
design that one section or element shall remain true within itself,
than that the various elements should remain true with one another.
The lathe, the planing machine, the drilling machine, and many others
of the now standard machine tools will never be superseded, and will
for a long time to come remain subjects of alteration and attempted
improvement in every detail. The head stock of a lathe--the back gear
in particular--is about as hard a thing to improve as the link motion
of a locomotive. Some arrangement by which a single motion would
change from fast to slow, and a substitute for the flanges on the
pulleys, which are intended to keep the belt out of the gear, but
never do, might be improvements. If the flanges were cast on the head
stock itself, and stand still, rather than on the pulley, where they
keep turning, the belt would keep out from between the gear for a
certainty. One motion should fasten a foot stock, and as secure as it
is possible to secure it, and a single motion free it so it could be
moved from end to end of the bed. The reason any lathe takes more than
a single motion is because of elasticity in the parts, imperfection in
the planing, and from another cause, infinitely greater than the
others, the swinging of the hold-down bolts.
Should not the propelling powers of a lathe slide be as near the point
of greatest resistance as possible, as is the case in a Sellers lathe,
and the guiding ways as close to the greatest resistance and
propelling power as possible, and all other necessary guiding surfaces
made to run as free as possible?
A common expression to be found among the description of new lathes is
the one that says "the carriage has a long bearing on the ways." Long
is a relative word, and the only place I have seen any long slides
among the lathes in the market is in the advertisements. But if any
one has the courage to make a long one, they will need something
besides material to make a success of it. It needs only that the
guiding side that should be long, and that must be as rigid as
possible--nothing short of casting the apron in the same piece will be
strong enough, because with a long, elastic guide heavy work will
spring it down and wear it away at the center, and then with light
work it will ride at the ends, with a chattering cut as a consequence.
An almost endless and likely profitless discussion has been indulged
in as to the proper way to guide a slide rest, and different opinions
exist. It is a question that, so far as principle is concerned, there
ought to be some way to settle which should not only govern the
question in regard to the slide rest of a lathe, but all slides that
work against a torsional resistance, as it may be called--that is, a
resistance that does not directly oppose the propelling power. In
other words, in a lathe the cutting point of the tool is not in line
with the lead screw or rack, and a twisting strain has to be resisted
by the slides, whereas in an upright drill the sliding sleeve is
directly over and in line with the drill, and subject to no side
strain.
Does not the foregoing statement that "the propelling power should be
as near the resistance as possible, and the guide be as near in line
with the two as possible," embody the true principle? Neither of the
two methods in common use meets this requirement to its fullest
extent. The two-V New England plan seems like sending two men to do
what one can do much better alone; and the inconsistency of guiding by
the back edge of a flat bed is prominently shown by considering what
the result would be if carried to an extreme. If a slide such as is
used on a twenty inch lathe were placed upon a bed or shears twenty
feet wide, it would work badly, and that which is bad when carried to
an extreme cannot well be less than half bad when carried half way.
The ease with which a cast iron bar can be sprung is many times
overlooked. There is another peculiarity about cast iron, and likely
other metals, which an exaggerated example renders more apparent than
can be done by direct statement. Cast iron, when subject to a bending
strain, acts like a stiff spring, but when subject to compression it
dents like a plastic substance. What I mean is this: If some plastic
substance, say a thick coating of mud in the street, be leveled off
true, and a board be laid upon it, it will fit, but if two heavy
weights be placed on the ends, the center will be thrown up in the air
far away from the mud; so, too, will the same thing occur if a
perfectly straight bar of cast iron be placed on a perfectly straight
planer bed--the two will fit; but when the ends of the bar are bolted
down, the center of the bar will be up to a surprising degree. And so
with sliding surfaces when working on oil. If to any extent elastic,
they will, when unequally loaded, settle through the oil where the
load exists and spring away where it is not.
The tool post or tool holder that permits of a tool being raised or
lowered and turned around after the tool is set, without any sacrifice
of absolute stability, will be better than one in which either one of
these features is sacrificed. Handiness becomes the more desirable as
the machines are smaller, but handiness is not to be despised even in
a large machine, except where solidity is sacrificed to obtain it.
The weak point in nearly all (and so nearly all that I feel pretty
safe in saying all) small planing machines is their absolute weakness
as regards their ability to resist torsional strain in the bed, and
both torsional and bending strain in the table. Is it an uncommon
thing to see the ways of a planer that has run any length of time cut?
In fact, is it not a pretty difficult thing to find one that is not
cut, and is this because they are overloaded? Not at all. Figure up at
even fifty pounds to the square inch of wearing surface what any
planer ought to carry, and you will find that it is not from
overloading. Twist the bed upon the floor (and any of them will twist
as easy as two basswood boards), and your table will rest the hardest
on two corners. Strap, or bolt, or wedge a casting upon the table, or
tighten up a piece between a pair of centers eight or ten inches above
the table, and bend the table to an extent only equal to the thickness
of the film of oil between the surface of the ways, and the large
wearing surface is reduced to two wearing points. In designing it
should always be kept in mind, or, in fact, it is found many times to
be the correct thing to do, to consider the piece as a stiff spring,
and the stiffer the better. The tooth of a gear wheel is a cast iron
spring, and if only treated as would be a spring, many less would be
broken. A point in evidence:
The pinions in a train of rolls, which compel the two or more rolls to
travel in unison, are necessarily about as small at the pitch line as
the rolls themselves; they are subject to considerable strain and a
terrible hammering by back lash, and break discouragingly frequent, or
do when made of cast iron, if not of very coarse pitch, that is, with
very few teeth--eleven or twelve sometimes.
In a certain case it became desirable to increase the number of teeth,
when it was found that the breakages occurred about as the square root
of their number. When the form was changed by cutting out at the root
in this form (Fig. 2), the breakage ceased.
a, Fig. 2, shows an ordinary gear tooth, and b the form as
changed; c and d show the two forms of the same width, but
increased to six times the length. If the two are considered as
springs, it will be seen that d is much less likely to be broken by
a blow or strain.
The remedy for the flimsy bed is the box section; the remedy for the
flimsy planer table is the deep box section, and with this advantage,
that the upper edge can be made to shelve over above the reversing
dogs to the full width between the housings.
The parabolic form of housing is elegant in appearance, but
theoretically right only when of uniform cross section. In some of the
counterfeit sort the designers seem to have seen the original Sellers,
remembering the form just well enough to have got the curve wrong end
up, and knowing nothing of the principle, have succeeded in building a
housing that is absolutely weak and absolutely ugly, with just enough
of the original left to show from where it was stolen. If the housing
is constructed on the brace plan, should not the braces be straight,
as in the old Bement, and the center line of strain pass through the
center line of the brace? If the housing is to take the form of a
curve, the section should be practically uniform, and the curve drawn
by an artist. Many times housings are quite rigid enough in the
direction of the travel of the table, but weak against side pressure.
The hollow box section, with secure attachment to the bed and a deep
cross beam at the top, are the remedies.
Raising and lowering cross heads, large and small, by two screws is a
slow and laborious job, and slow when done by power. Counterweights
just balancing the cross head, with metal straps rather than chains or
ropes, large wheels with small anti-friction journals, and the cross
head guarded by one post only, changes a slow to a quick arrangement,
and a task to a comfort. Housings of the hollow box section furnish an
excellent place for the counterweights.
The moving head, which is not expected to move while under pressure,
seems to have settled into one form, and when hooked over a square
ledge at the top, a pretty satisfactory form, too. But in other
machines built in the form of planing machines, in which the head is
traversed while cutting, as is the case with the profiling machine,
the planer head form is not right. Both the propelling screw, or
whatever gives the side motion, should be as low down as possible, as
should also be the guide.
There is a principle underlying the Sellers method of driving a planer
table that may be utilized in many ways. The endurance goes far beyond
any man's original expectations, and the explanation, very likely,
lies in the fact that the point of contact is always changing. To
apply the same principle to a common worm gear it is only necessary to
use a worm in a plain spur gear, with the teeth cut at an angle the
wrong way, and set the worm shaft at an angle double the amount,
rather than at 90°. Such a worm gear will, I fancy, outwear a dozen of
the scientific sort. It would likely be found a convenience to have
the head of a planing machine traverse by a handle or crank attached
to itself, so it could be operated like the slide rest of a lathe,
rather than as is now the case from the end of the cross head. The
principle should be to have things convenient, even at an additional
cost. Anything more than a single motion to lock the cross head to the
housing or stanchions should not be countenanced in small planers at
least. Many of the inferior machines show marked improvements over the
better sorts, so far as handiness goes, while there is nothing to
hinder the handy from being good and the good handy.
When we consider that since the post-drilling machine first made its
appearance, there have been added Blasdell's quick return, the
automatic feed, belt-driven spindles, back gears placed where they
ought to be, with many minor improvements, it is not safe to assume
that the end has been reached; and when we consider that as a piece of
machine designing, considered in an artistic sense entirely, the
Bement post drill is the finest the world ever saw (the Porter-Allen
engine not excepted, which is saying a good deal), is it not strange
that of all mechanical designs none other has taken on such outrageous
forms as this?
One thing that would seem to be desirable, and that ordinary skill
might devise, is some sort of snap clutch by which the main spindle
could be stopped instantly by touching a trigger with the foot; many
drills and accidents would be saved thereby. Of the many special
devices I have seen for use on a drilling machine, one used by Mr.
Lipe might be made of universal use. It is in the form of a bracket or
knee adjustably attached to the post, which has in its upper surface a
V into which round pieces of almost any size can be fastened, so that
the drill will pass through it diametrically. It is not only useful in
making holes through round bars, but straight through bosses and
collars as well.
The radial drill has got so it points its nose in all directions but
skyward, but whether in its best form is not certain. The handle of
the belt shipper, in none that I have seen, follows around within
reach of the drill as conveniently as one would like.
As the one suggestion I have to make in regard to the shaping machine
best illustrates the subject of maintaining true wearing surfaces, I
will leave it until I reach that part of my paper.
(_To be continued._)
* * * * *
THE MECHANICS OF A LIQUID.
A liquid comes in handy sometimes in measuring the volume of a
substance where the length, breadth, and thickness is difficult to get
at. It is a very simple operation, only requiring the material to be
plunged under water and measure the amount of displacement by giving
close attention to the overflow. It is a process that was first
brought into use in the days when jewelers and silversmiths were
inclined to be a little dishonest and to make the most of their
earnings out of the rule of their country. If we remember rightly, the
voice of some one crying "Eureka" was heard about that time from
somebody who had been taking a bath up in the country some two miles
from home. Tradition would have us believe that the inventor left for
the patent office long before his bathing exercises were half through
with, and that he did the most of his traveling at a lively rate while
on foot, but it is more reasonable to suppose that bath tubs were in
use in those days, and that he noticed, as every good philosopher
should, that his bathing solution was running over the edge of the tub
as fast as his body sunk below the surface. Taking to the heels is
something that we hear of even at this late day.
[Illustration]
It was not many years ago that an inventor of a siphon noticed how
water could be drawn up hill with a lamp wick, and the thought struck
him that with a soaking arrangement of this kind in one leg of the
siphon a flow of water could be obtained that would always be kept in
motion. Without taking a second thought he dropped his work in the hay
field, and ran all the way to London, a distance of twenty miles, to
lay his scheme before a learned man of science. He must have felt like
being carried home on a stretcher when he learned that a performance
of this kind was a failure. Among the others who have given an
exhibition of this kind we notice an observer who was more successful.
Being an overseer in a cotton mill, he had only to run over to his
dining room and secure two empty fruit jars and pipe them up, as
shown. He had had trouble in measuring volume by the liquid process by
having everything he attempted to measure get a thorough wetting, and
there were many substances that were to be experimented upon that
would not stand this part of the operation, such as fibers and a
number of pulverized materials. One of the jars was packed in tight,
nearly half full of cotton, and the other left entirely empty. The
question now is to measure the volume of cotton without bringing any
of the fibers in contact with the water. The liquid is poured into the
tunnel in the upright tube under head enough to partially fill the
jars when the overflow that stands on a level with the line, D E, is
open to allow the air in each jar to adjust itself as the straight
portions are wanted to work from. The overflow is then closed and head
enough of water put on to compress the air in the empty jar down into
half its volume. It may take a pipe long enough to reach up into the
second story, but it need not be a large one, and pipes round a cotton
mill are plentiful. In the jar containing cotton the water has not
risen so high, there being not so much air to compress, and comes to
rest on the line, C. Now we have this simple condition to work from.
If the water has risen so as to occupy half of the space that has been
taken up by the amount of air in one jar, it must have done the same
in the other, and if it could have been carried to twice the extent in
volume would reach the bottom of the jar in the one containing nothing
but air, and to the line, H I, in the jar containing cotton.
The fibers then must have had an amount of material substance about
them to fill the remaining space entirely full, so that a particle of
air could not be taken into account anywhere. The cotton has produced
the same effect that a solid substance would do if it just filled the
space shown above the line, H I, for the water has risen into half the
space that is left below it. This enables an overseer to look into the
material substance of textile fibers by bringing into use the
elasticity of atmospheric air, reserving the liquid process for
measuring volume to govern the amount of compressibility.--_Boston
Journal of Commerce._
* * * * *
VOLUTE DOUBLE DISTILLING CONDENSER.
This distiller and condenser which we illustrate has been designed,
says _Engineering_, for the purpose of obtaining fresh water from sea
water. It is very compact, and the various details in connection with
it may be described as follows: Steam from the boiler is admitted into
the evaporator through a reducing valve at a pressure of about 60 lb.,
and passing through the volute, B, evaporates the salt water contained
in the chamber, C; the vapor thus generated passing through the pipe,
D, into the volute condenser, E, where it is condensed. The fresh
water thus obtained flows into the filter, from which it is pumped
into suitable drinking tanks.
[Illustration: VOLUTE DOUBLE DISTILLING APPARATUS.]
The steam from the boiler after passing through the volute, B, is
conveyed by means of a pipe to the second volute, H, where it is
condensed, and the water resulting is conveyed by means of a pump to
the hot well or feed tank. The necessary condensing water enters at J
and is discharged at K. The method of keeping the supply of salt water
in the evaporator at a constant level is very efficient and ingenious.
To the main circulating discharge pipe, a small pipe, L, is fitted,
which is in communication with the chamber, M, and through this the
circulating sea water runs back until it attains a working level in
the evaporator, when a valve in the end of pipe, L, is closed by the
action of the float, N, the regulation of admission being thus
automatic and certain. The steam from the boiler can be regulated by
means of a stop valve, and the pressure in the evaporator should not
exceed 4 lb., while the pressure gauge is so arranged that the
pressure in both condenser and evaporator is shown at the same time. A
safety valve is fitted at the top of the condenser, and an automatic
blow-off valve, P, is arranged to blow off when a certain density of
brine has been attained in the evaporator. The "Esco" triple pump
(Fig. 3), which has been specially manufactured for this purpose, has
three suctions and deliveries, one for circulating water, the second
for the condensed steam, and a third for the filtered drinking water,
so that the latter is kept fresh and clean.
The condenser and pumps are manufactured by Ernest Scott & Co., Close
Works, Newcastle on Tyne, and were shown by them at the late
exhibition in their town.
* * * * *
IMPROVED CURRENT METER.
Paul Kotlarewsky, of St. Petersburg, has invented an instrument for
measuring or ascertaining the velocity of water and air currents.
Upon the shaft or axis of the propeller wheel, or upon a shaft geared
therewith, there is a hermetically closed tube or receptacle, D, which
is placed at right angles with the shaft, and preferably so that its
longitudinal axis shall intersect the axis of said shaft. In this tube
or receptacle is placed a weight, such as a ball, which is free to
roll or slide back and forth in the tube. The effect of this
arrangement is, that as the shaft revolves, the weight will drop
alternately toward opposite ends of the tube, and its stroke, as it
brings up against either end, will be distinctly heard by the observer
as well as felt by him if, as is usually the case, the apparatus when
in use is held by him. By counting the strokes which occur during a
given period of time, the number of revolutions during that period can
readily be ascertained, and from that the velocity of the current to
be measured can be computed in the usual way.
When the apparatus is submerged in water, by a rope held by the
observer, it will at once adjust itself to the direction of the
current. The force of the current, acting against the wings or blades
of the propeller wheel, puts the latter in revolution, and the tube,
D, will be carried around, and the sliding weight, according to the
position of the tube, will drop toward and bring up against
alternately opposite ends of said tube, making two strokes for every
revolution of the shaft.
[Illustration]
* * * * *
THE FLOWER INDUSTRY OF GRASSE.
A paper on this subject was read before the Chemists' Assistants'
Association on March 8, by Mr. F.W. Warrick, and was listened to with
much interest.
Mr. Warrick first apologized for presenting a paper on such a
frivolous subject to men who had shown themselves such ardent
advocates of the higher pharmacy, of the "ologies" in preference to
the groceries, perfumeries, and other "eries." But if perfumery could
not hope to take an elevated position in the materiæ pharmaceuticæ, it
might be accorded a place as an adjunct, if only on the plea that
those also serve who only stand and wait.
Mr. Warrick mentioned that his family had been connected with this
industry for many years, and that for many of the facts in the paper
he was indebted to a cousin who had had twenty years' practical
experience in the South, and who was present that evening.
GRASSE.
The town of Grasse is perhaps more celebrated than any other for its
connection with the perfume industry in a province which is itself
well known to be its home.
This, the department of the Alpes Maritimes, forms the southeastern
corner of France. Its most prominent geographical features are an
elevated mountain range, a portion of the Alps, and a long seaboard
washed by the Mediterranean--whence the name Alpes Maritimes.
The calcareous hills round Grasse and to the north of Nice are more or
less bare, though they were at one time well wooded; the reafforesting
of these parts has, however, made of late great progress. Nearer the
sea vegetation is less rare, and there many a promontory excites the
just admiration of the visitor by its growth of olives, orange and
lemon trees, and odoriferous shrubs. Who that has ever sojourned in
this province can wonder that Goethe's Mignon should have ardently
desired a return to these sunny regions?
Visitors on these shores on the first day of this year found Goethe's
lines more poetical than true--
Where a wind ever soft from the blue heaven blows,
And the groves are of laurel, and myrtle, and rose;
for they gathered round their fires and coughed and groaned in chorus,
and entertained each other with accounts of their ailments. But this
was exceptional, and the climate of the Alpes Maritimes is on the
whole as near perfection as anything earthly can be. This, however, is
not due to its latitude, but rather to its happy protection from the
north by its Alps and to its being bathed on the south by the warm
Mediterranean and the soft breezes of an eastern wind (which evidently
there bears a different reputation to that which it does with us). The
mistral, or cold breeze from the hills, is indeed the only climatic
enemy, if we except an occasional earthquake.
The town of Grasse itself is situated in the southern portion of the
department, and enjoys its fair share of the advantages this situation
affords. It is about ten miles from Cannes (Lord Brougham's creation),
and, as the crow flies, twenty-five miles from Nice, though about
forty miles by rail, for the line runs down to Cannes and thence along
the shore to Nice.
Built on the side of a hill some 1,000 feet above the level of the
sea, the town commands magnificent views over the surrounding country,
especially in the direction of the sea, which is gloriously visible.
An abundant stream, the Foux, issuing from the rocks just above the
town, is the all productive genius of the place; it feeds a hundred
fountains and as many factories, and then gives life to the
neighboring fields and gardens.
The population of Grasse is about 12,000, and the flora of its
environs represents almost all the botany of Europe. Among the
splendid pasture lands, 7,000 feet above the sea, are fields of
lavender, thyme, etc. From 7,000 to 6,000 feet there are forests of
pine and other gymnosperms. From 6,000 to 4,000 feet firs and the
beech are the most prominent trees. Between 4,000 and 2,000 feet we
find our familiar friends the oak, the chestnut, cereals, maize,
potatoes. Below this is the Mediterranean region. Here orange, lemon,
fig, and olive trees, the vine, mulberry, etc., flourish in the open
as well as any number of exotics, palms, aloes, cactuses, castor oil
plants, etc. It is in this region that nature with lavish hand bestows
her flowers, which, unlike their compeers in other lands, are not born
to waste their fragrance on the desert air or to die "like the bubble
on the fountain," but rather (to paraphrase George Eliot's lofty
words) to die, and live again in fats and oils, made nobler by their
presence.
The following are the plants put under contribution by the perfume
factories of the district, viz., the orange tree, bitter and sweet,
the lemon, eucalyptus, myrtle, bay laurel, cherry laurel, elder; the
labiates; lavender, spike, thyme, etc.; the umbelliferous fennel and
parsley, the composite wormwood and tarragon, and, more delicate than
these, the rose, geranium, cassie, jasmin, jonquil, mignonette, and
violet.
THE PERFUME FACTORY.
In the perfume factory everything is done by steam. Starting from the
engine room at the bottom, the visitor next enters the receiving room,
where early in the morning the chattering, patois-speaking natives
come to deliver the flowers for the supply of which they have
contracted. The next room is occupied with a number of steam-jacketed
pans, a mill, and hydraulic presses. Next comes the still room, the
stills in which are all heated by steam. In the "extract" department,
which is next reached, are large tinned-copper drums, fitted with
stirrers, revolving in opposite directions on vertical axes.
Descending to the cellar--the coolest part of the building--we find
the simple apparatus used in the process of enfleurage. The apparatus
is of two kinds. The smaller is a frame fitted with a sheet of stout
glass. A number of these, all of the same size, when placed one on the
top of the other, form a tolerably air tight box. The larger is a
frame fitted with wire netting, over which a piece of molleton is
placed. The other rooms are used for bottling, labeling, etc.
The following are some of the details of the cultivation and
extraction of perfumes as given in Mr. Warrick's paper:
ORANGE PERFUMES.
The orange tree is produced from the pip, which is sown in a sheltered
uncovered bed. When the young plant is about 4 feet high, it is
transplanted and allowed a year to gain strength in its new
surroundings. It is then grafted with shoots from the Portugal or
Bigaradier. It requires much care in the first few years, must be well
manured, and during the summer well watered, and if at all exposed
must have its stem covered up with straw in winter. It is not expected
to yield a crop of flowers before the fourth year after
transplantation. The flowering begins toward the end of April and
lasts through May to the middle of June. The buds are picked when on
the point of opening by women, boys, and girls, who make use of a
tripod ladder to reach them. These villagers carry the fruits (or,
rather, flowers) of their day's labor to a flower agent or
commissionnaire, who weighs them, spreads them out in a cool place
(the flowers, not the villagers), where they remain until 1 or 2 A.M.;
he then puts them into sacks, and delivers them at the factory before
the sun has risen. They are here taken in hand at once; on exceptional
days as many as 160 tons being so treated in the whole province. After
the following season, say end of June, the farmers prune their trees;
these prunings are carted to the factory, where the leaves are
separated and made use of.
During the autumn the ground round about the trees is well weeded, dug
about, and manured. The old practice of planting violets under the
orange trees is being abandoned. Later on in the year those blossoms
which escaped extermination have developed into fruits. These, when
destined for the production of the oil, are picked while green.
The orange trees produce a second crop of flowers in autumn, sometimes
of sufficient importance to allow of their being taken to the
factories, and always of sufficient importance to provide brides with
the necessary bouquets.
Nature having been thus assisted to deliver these, her wonderful
productions, the flowers, the leaves, and the fruits of the orange
tree, at the factory, man has to do the rest. He does it in the
following manner:
The flowers are spread out on the stone floor of the receiving room in
a layer some 6 to 8 inches deep; they are taken in hand by young
girls, who separate the sepals, which are discarded. Such of the
petals as are destined for the production of orange flower water and
neroli are put into a still through a large canvas chute, and are
covered with water, which is measured by the filling of reservoirs on
the same floor. The manhole of the still is then closed, and the
contents are brought to boiling point by the passage of superheated
steam through the coils of a surrounding worm. The water and oil pass
over, are condensed, and fall into a Florentine receiver, where the
oil floating on the surface remains in the flask, while the water
escapes through the tube opening below. A piece of wood or cork is
placed in the receiver to break up the steam flowing from the still;
this gives time for the small globules of oil to cohere, while it
breaks the force of the downward current, thus preventing any of the
oil being carried away.
The first portions of the water coming from the still are put into
large tinned copper vats, capable of holding some 500 gallons, and
there stored, to be drawn off as occasion may require into glass
carboys or tinned copper bottles. This water is an article of very
large consumption in France; our English cooks have no idea to what an
extent it is used by the _chefs_ in the land of the "darned mounseer."
The oil is separated by means of a pipette, filtered, and bottled off.
It forms the oil of neroli of commerce; 1,000 kilos. of the flowers
yield 1 kilo. of oil. That obtained from the flowers of the
Bigaradier, or bitter orange, is the finer and more expensive quality.
The delicate scent of orange flowers can be preserved quite unchanged
by another and more gentle process, viz., that of maceration. It was
noticed by some individual, whose name has not been handed down to us,
that bodies of the nature of fat and oil are absorbers of the
odor-imparting particles exhaled by plants. This property was seized
upon by some other genius equally unknown to fame, who utilized it to
transfer the odor of flowers to alcohol.
Where oil is used it is the very finest olive, produced by the trees
in the neighborhood. This is put into copper vats holding about 50
gallons; 1 cwt. of flowers is added. After some hours the flowers are
strained out by means of a large tin sieve. The oil is treated with
another cwt. of flowers and still another, until sufficiently
impregnated. It is then filtered through paper until it becomes quite
bright; lastly it is put into tins, and is ready for exportation or
for use in the production of extracts.
Where fat is employed as the macerating agent, the fat used is a
properly adjusted mixture of lard and suet, both of which have been
purified and refined during the winter months, and kept stored away in
well closed tins.
One cwt. of the fat is melted in a steam-jacketed pan, and poured into
a tinned copper vat capable of holding from 5 to 6 cwt. About 1 cwt.
of orange flowers being added, these are well stirred in with a wooden
spatula. After standing for a few hours, which time is not sufficient
for solidification to take place, the contents are poured into shallow
pans and heated to 60° C. The mixture thus rendered more fluid is
poured on to a tin sieve; the fat passes through, the flowers remain
behind. These naturally retain a large amount of macerating liquor. To
save this they are packed into strong canvas bags and subjected to
pressure between the plates of a powerful hydraulic press. The fat
squeezed out is accompanied by the moisture of the flowers, from which
it is separated by skimming. Being returned to the original vat, our
macerating medium receives another complement of flowers to rob of
their scent, and yet others, until the strength of the pomade desired
is reached. The fat is then remelted, decanted, and poured into tins
or glass jars.
To make the extrait, the pomade is beaten up with alcohol in a special
air tight mixing machine holding some 12 gallons, stirrers moved by
steam power agitating the pomade in opposite directions. After some
hours' agitation a creamy liquid is produced, which, after resting,
separates, the alcohol now containing the perfume. By passing the
alcohol through tubes surrounded by iced water, the greater part of
the dissolved fat is removed.
These are the processes applied to the flowers. The leaves are
distilled only for the oil of petit grain. This name was given to the
oil because it was formerly obtained from miniature orange fruits.
From 1,000 kilos. of leaves 2 kilos. of oil are obtained.
The oil obtained from the fruit of the orange, like that of the lemon,
is extracted at Grasse by rolling the orange over the pricks of an
_ecueille_, an instrument with a hollow handle, into which the oil
flows. The oil is sometimes taken up by a sponge. Where the oil is
produced in larger quantities, as at Messina, more elaborate apparatus
is employed. A less fragrant oil is obtained by distilling the
raspings of the rind.
THE EUCALYPTUS, MYRTLE, ETC.
Of later introduction than the trees of the orange family is the
Eucalyptus globulus, which, not being able to compete with the former
in the variety of nasal titillations it gives rise to, probably
consoles itself with coming off the distinct victor in the department
of power and penetration. The leaves and twigs of this tree are
distilled for oil. This oil is in large demand on the Continent, the
fact of there being no other species than the globulus in the
neighborhood being a guarantee of the uniformity of the product.
Whereas the eucalyptus is but a newcomer in these regions, another
member of the same family, the common myrtle, can date its
introduction many centuries back. An oil is distilled from its leaves,
and also a water.
Associated with the myrtle we find the leaves of the bay laurel,
forming the victorious wreaths of the ancients. The oil produced is
the oil of bay laurel, oil of sweet bay. This must not be confounded
with the oil of bays of the West Indies, the produce of the _Myrcia
acris_; nor yet with the cherry laurel, a member of yet another
family, the leaves of which are sometimes substituted for those of the
sweet bay. The leaves of this plant yield the cherry laurel water of
the B.P. It can hardly be said to be an article of perfumery. It also
yields an oil.
Another water known to the British Pharmacopoeia is that produced from
the flowers of the elder, which flourishes round about Grasse.
The rue also grows wild in these parts, and is distilled.
THE LABIATES.
The family which overshadows all others in the quantity of essential
oils which it puts at the disposal of the Grassois and their neighbors
is that of the Labiatæ. Foremost among these we have the lavender,
spike, thyme, and rosemary. These are all of a vigorous and hardy
nature and require no cultivation. The tops of these plants are
generally distilled _in situ_, under contract with the Grasse
manufacturer, by the villagers in the immediate vicinity. The higher
the altitude at which these grow, the more esteemed the oil. The
finest oil of lavender is produced by distilling the flowers only.
About 100 tons of lavender, 25 of spike, 40 of thyme, and 20 of
rosemary are sent out from Grasse every year.
Among the less abundant labiates of these parts is the melissa, which
yields, however, a very fragrant oil.
In the same family we have the sage and the sweet or common basil,
also giving up their essential oils on distillation.
THE UMBELLIFERS.
Whereas the flowers of the labiate family are treated by the
distillers as favorites are by the gods, and are cut off in their
youth, those of the Umbelliferæ are allowed to mature and develop into
the oil-yielding fruits. Its representatives, the fennel and parsley,
grow wild round about the town, and are laid under contribution by the
manufacturers.
The Composites are represented by the wormwood and tarragon
(_Estragon_).
THE GERANIUM.
Oil of geranium is produced from the rose or oak-leaved geranium,
cuttings of which are planted in well sheltered beds in October.
During the winter they are covered over with straw matting. In April
they are taken up, and planted in rows in fields or upon easily
irrigated terraces. Of water they require _quantum sufficit_; of
nature's other gift, which cheers and not inebriates--the glorious
sunshine--they cannot have too much. They soon grow into bushes three
or four feet high. At Nice they generally flower at the end of August.
At Grasse and cooler places they flower about the end of October. The
whole flowering plant is put into the still.
THE ROSE.
Allied to the oil of geranium in odor are the products of the rose.
The Rose de Provence is the variety cultivated. It is grown on gentle
slopes facing the southeast. Young shoots are taken from a
five-year-old tree, and are planted in ground which has been well
broken up to a depth of three or four feet, in rows like vines. When
the young plant begins to branch out, the top of it is cut off about a
foot from the ground. During the first year the farmer picks off the
buds that appear, in order that the whole attention of the plant may
be taken up in developing its system. In the fourth or fifth year the
tree is in its full yielding condition. The flowering begins about
mid-April, and lasts through May to early June. On some days as many
as 150 tons of roses are gathered in the province of the Alpes
Maritimes.
The buds on the point of opening are picked in the early morning.
Scott says they are "sweetest washed with morning dew." The purchaser
may think otherwise where the dew has to be paid for.
The flowering season over, the trees are allowed to run wild. In
January they are pruned, and the branches left are entwined from tree
to tree all along the line, and form impenetrable fences.
A rose tree will live to a good age, but does not yield much after its
seventh year. At that period it is dug up and burned, and corn,
potatoes, or some other crop is grown on the land for twelve months or
more.
In the factory the petals are separated from the calyx, and are
distilled with water for the production of rose water and the otto.
For the production of the huile and pomade they are treated by
maceration. They are finished off, however, by the process of
enfleurage, in which the frames before alluded to are made use of. The
fat, or pomade, is spread on to the glass on both sides. The blossoms
are then lightly strewn on to the upper surface. A number of trays so
filled are placed one on the top of the other to a convenient height,
forming a tolerably air tight box. The next day the old flowers are
removed, and fresh ones are substituted for them. This is repeated
until the fat is sufficiently impregnated. From time to time the
surface of the absorbent is renewed by serrating it with a comb-like
instrument. This, of course, is necessary in order to give the hungry,
non-saturated lower layers a chance of doing their duty.
Where oil is the absorbent, the wired frames are used in connection
with cloths. The cloth acts as the holder of the oil, and the flowers
are spread upon it, and the process is conducted in the same way as
with the frames with glass.
From the pomade the extrait de rose is made in the same way as the
orange extrait.
CASSIE.
The stronger, though less delicate, cassie is grown from seeds, which
are contained in pods which betray the connection of this plant with
the leguminous family. After being steeped in water they are sown in a
warm and well sheltered spot. When two feet high the young plant is
grafted and transplanted to the open ground--ground well exposed to
the sun and sheltered from the cold winds. It flourishes best in the
neighborhood of Grasse and Cannes. The season of flowering is from
October to January or February, according to the presence or absence
of frost. The flowers are gathered twice a week in the daytime, and
are brought to the factories in the evening. They are here subjected
to maceration.
JONQUIL.
A plant of humbler growth is the jonquil. The bulbs of this are set
out in rows. The flowers put in an appearance about the end of March,
four or five on each stem. Each flower as it blooms is picked off at
the calyx. They are treated by maceration and enfleurage, chiefly the
latter. The harvesting period of the jonquil is of very short
duration, and it often takes two seasons for the perfumer to finish
off his pomades of extra strength. The crop is also very uncertain.
JASMIN.
A more reliable crop is that of the jasmin. This plant is reared from
cuttings of the wild jasmin, which are put in the earth in rows with
trenches between. Level ground is chosen; if hillside only is
available, this is formed into a series of terraces. When strong
enough, the young stem is grafted with shoots of the _Jasminum
grandiflorum_. The first year it is allowed to run wild, the second it
is trained by means of rods, canes and other appliances. At the
approach of winter the plants are banked up with earth to half their
height. The exposed parts then die off. When the last frost of winter
is gone the earth is removed, and what remains of the shrub is trimmed
and tidied up for the coming season. It grows to four or five feet.
Support is given by means of horizontal and upright poles, which join
the plants of one row into a hedge-like structure. Water is provided
by means of the ditches already mentioned. When not used for this
purpose, the trenches allow of the passage of women and children to
gather the flowers. These begin to appear in sufficient quantity to
repay collecting about the middle of July. The jasmin is collected as
soon as possible after it blooms. This occurs in the evening, and up
to about August 15, early enough for the blossoms to be gathered the
same day. They are delivered at the factories at once, where they are
put on to the chassis immediately; the work on them continuing very
often till long after midnight. Later on in the year they are gathered
in the early morning directly the dew is off. The farmer is up
betimes, and as soon as he sees the blossoms are dry he sounds a bugle
(made from a sea shell) to announce the fact to those engaged to pick
for him.
TUBEROSE.
The tuberose is planted in rows in a similar way to the jasmin. The
stems thrown up by the bulbs bear ten or twelve flowers. Each flower
as it blooms is picked off. The harvesting for the factories takes
place from about the first week in July to the middle of October.
There is an abundant yield, indeed, after this, but it is only of
service to the florist, the valued scent not being present in
sufficient quantity. The flowers are worked up at the factory directly
they arrive by the enfleurage process.
MIGNONETTE.
The _reseda_, or mignonette, is planted from seed, as here in England.
The flowering tops are used to produce the huile or pomade.
VIOLETS.
Last in order and least in size comes the violet. For "the flower of
sweetest smell is shy and lowly," and has taken a modest place in the
paper.
Violets are planted out in October or April. October is preferred, as
it is the rainy season; nor are the young plants then exposed to the
heat of the sun or to the drought, as they would be if starting life
in April.
The best place for them is in olive or orange groves, where they are
protected from the too powerful rays of the sun in summer and from the
extreme cold in winter. Specks of violets appear during November. By
December the green is quite overshadowed, and the whole plantation
appears of one glorious hue. For the leaves, having developed
sufficiently for the maintenance of the plant, rest on their oars, and
seem to take a silent pleasure in seeing the young buds they have
protected shoot past them and blossom in the open.
The flowers are picked twice a week; they lose both color and flavor
if they are allowed to remain too long upon the plant. They are
gathered in the morning, and delivered at the factories by the
commissionnaires or agents in the afternoon, when they are taken in
hand at once.
The products yielded by this flower are prized before all others in
the realms of perfumery, and cannot be improved; for, as one great
authority on all matters has said: "To throw a perfume on the violet
... were wasteful and ridiculous excess."
* * * * *
HOW TO MAKE PHOTO. PRINTING PLATES.
The drawing intended for reproduction is pinned on a board and placed
squarely before a copying camera in a good, even light. The lens used
for this purpose must be capable of giving a perfectly sharp picture
right up to the edges, and must be of the class called rectilinear,
i.e., giving straight lines. The picture is then accurately focused
and brought to the required size. A plate is prepared in the dark room
by the collodion process, which is then exposed in the camera for the
proper time and developed in the ordinary way. After development, the
plate is fixed and strongly intensified, in order to render the white
portions of the drawings as opaque as possible. On looking through a
properly treated negative of this kind, it will be seen that the parts
representing the lines and black portions of the drawing are clear
glass, and the whites representing the paper a dense black.
The negative, after drying, is ready for the next operation, i.e.,
printing upon zinc. This is done in several ways. One method will,
however, be sufficient for the purpose here. I obtain a piece of the
bichromatized gelatine paper previously mentioned, and place it on the
face of the negative in a printing frame. This is exposed to sunlight
(if there is any) or daylight for a period varying from five to thirty
minutes, according to the strength of the light. This exposed piece of
paper is then covered all over with a thin coating of printing ink,
and wetted in a bath of cold water. In a few minutes the ink leaves
the white or protected parts of the paper, remaining only on the lines
where the light has passed through the negative and affected the
gelatine. We now have a transcript of the drawing in printing ink, on
a paper which, as soon as dry, is ready for laying down on a piece of
perfectly clean zinc, and passing through a press. The effect and
purpose of passing this cleaned sheet of zinc through the press in
contact with the picture on the gelatine paper is this: Owing to the
stronger attraction of the greasy ink for the clean metal than for the
gelatine, it leaves its original support, and attaches itself strongly
to the zinc, giving a beautifully sharp and clean impression of our
original drawing in greasy ink on the surface of the zinc. The zinc
plate is next damped and carefully rolled up with a roller charged
with more printing ink, and the image is thus made strong enough to
resist the first etching. This etching is done in a shallow bath,
which is so arranged that it can be rocked to and fro. For the first
etching, very weak solution of nitric acid and water is used. The
plate is placed with this acid solution in the bath, and steadily
rocked for five or ten minutes. The plate is then taken out, washed,
and again inked; then it is dusted over with powdered resin, which
sticks to the ink on the plate. After this the plate is heated until
the ink and resin on the lines melt together and form a strong
acid-resisting varnish over all the work. The plate is again put into
the acid etching bath and further etched. These operations are
repeated five or six times, until the zinc of the unprotected or white
part of the picture is etched deep enough to allow the lines to be
printed clean in a press, like ordinary type or an engraved wood
block. I ought perhaps to explain that between each etching the plate
is thoroughly inked, and that this ink is melted down the sides of the
line, so as to protect the sides as well as the top from the action of
the acid; were this neglected, the acid would soon eat out the lines
from below. The greatest skill and care is, therefore, necessary in
this work, especially so in the case of some of the exquisitely fine
blocks which are etched for some art publications.
There are many details which are necessary to successful etching, but
those now given will be sufficient to convey to you generally the
method of making the zinc plate for the typographic block. After
etching there only remains the trimming of the zinc, a little touching
up, and mounting it on a block of mahogany or cherry of exact
thickness to render it type high, and it is now ready for insertion
with type in the printer's form. From a properly etched plate hundreds
of thousands of prints may be obtained, or it may be electrotyped or
stereotyped and multiplied indefinitely.--_G.S. Waterlow, Brit. Jour.
Photo._
* * * * *
ANALYSIS OF A HAND FIRE GRENADE.
By CHAS. CATLETT and R.C. PRICE.
The analyses of several of these "fire extinguishers" have been
published, showing that they are composed essentially of an aqueous
solution of one or more of the following bodies; sodium, potassium,
ammonium, and calcium chlorides and sulphates, and in small amount
borax and sodium acetate; while their power of extinguishing fire is
but three or fourfold that of water.
One of these grenades of a popular brand of which I have not found an
analysis was examined by Mr. Catlett with the following results: The
blue corked flask was so open as to show that it contained no gas
under pressure, and upon warming its contents, but 4 or 5 cubic inches
of a gas were given off. The grenade contained about 600 c.c. of a
neutral solution, which gave on analysis:
In 1000 c.c. In the Flask.
Grammes. Grains.
Calcium chloride¹ 92.50 850.8
Magnesium " 18.71 173.2
Sodium " 22.20 206.9
Potassium " 1.14 10.6
------ ------
134.55 1241.5
¹Trace of bromide.
As this mixture of substances naturally suggested the composition of
the "mother liquors" from salt brines, Mr. Price made an analysis of
such a sample of "bittern" from the Snow Hill furnace, Kanawha Co.,
W.Va., obtaining the following composition:
In 1000 c.c. In 200 c.c.
Grammes. Grains.
Calcium chloride¹ 299.70 925.8
Magnesium " 56.93 175.7
Strontium " 1.47 4.5
Sodium " 20.16 62.2
Potassium " 5.13 15.8
------ ------
383.39 1184.0
¹Trace of bromide.
There is of course some variation in the bittern obtained from
different brines, but it appears of interest to call attention to this
correspondence in composition, as indicating that the liquid for
filling such grenades is obtained by adding two volumes of water to
one of the "bittern." The latter statement is fairly proved by the
presence of the bromine, and certainly from an economical standpoint
such should be its method of manufacture.--_Amer. Chem. Jour._
* * * * *
MOLECULAR WEIGHTS.
A new and most valuable method of determining the molecular weights of
non-volatile as well as volatile substances has just been brought into
prominence by Prof. Victor Meyer (_Berichte_, 1888, No. 3). The method
itself was discovered by M. Raoult, and finally perfected by him in
1886, but up to the present has been but little utilized by chemists.
It will be remembered that Prof. Meyer has recently discovered two
isomeric series of derivatives of benzil, differing only in the
position of the various groups in space. If each couple of isomers
possess the same molecular weight, a certain modification of the new
Van't Hoff-Wislicenus theory as to the position of atoms in space is
rendered necessary; but if the two are polymers, one having a
molecular weight n times that of the other, then the theory in its
present form will still hold. Hence it was imperative to determine
without doubt the molecular weight of some two typical isomers. But
the compounds in question are not volatile, so that vapor density
determinations were out of the question. In this difficulty Prof.
Meyer has tested the discovery of M. Raoult upon a number of compounds
of known molecular weights, and found it perfectly reliable and easy
of application. The method depends upon the lowering of the
solidifying point of a solvent, such as water, benzine, or glacial
acetic acid, by the introduction of a given weight of the substance
whose molecular weight is to be determined. The amount by which the
solidifying point is lowered is connected with the molecular weight,
M, by the following extremely simple formula: M = T x (P / C); where C
represents the amount by which the point of congelation is lowered, P
the weight of anhydrous substance dissolved in 100 grammes of the
solvent, and T a constant for the same solvent readily determined from
volatile substances whose molecular weights are well known. On
applying this law to the case of two isomeric benzil derivatives, the
molecular weights were found, as expected, to be identical, and not
multiples; hence Prof. Meyer is perfectly justified in introducing the
necessary modification in the "position in space" theory. Now that
this generalization of Raoult is placed upon a secure basis, it takes
its well merited rank along with that of Dulong and Petit as a most
valuable means of checking molecular weights, especially in
determining which of two or more possible values expresses the
truth.--_Nature._
* * * * *
[Continued from SUPPLEMENT, No. 642, page 10258.]
THE DIRECT OPTICAL PROJECTION OF ELECTRO-DYNAMIC LINES OF FORCE AND
OTHER ELECTRO-DYNAMIC PHENOMENA.[1]
[Footnote 1: An expansion of two papers read before the A.A.A.S.
at the Ann Arbor meeting.]
By Prof. J.W. MOORE.
II. LOOPS.
If the wire, with its lines of force, be bent into the form of a
vertical circle 1-1/8 in. in diameter, and fixed in a glass plate,
some of the lines of force will be seen parallel to the axis of the
circle. If the loop is horizontal, the lines become points.
[Illustration: Fig. 14.]
[Illustration: Fig. 14a.]
FIELDS OF LOOPS AND MAGNETS.
Place now a vertical loop opposite to the pole of a short bar magnet
cemented to the glass plate with the N pole facing it. If the current
passes in one direction the field will be as represented by Fig.
14b; if it is reversed by the commutator, Fig. 14c is an image of
the spectrum. Applying Faraday's second principle, it appears that
attraction results in the first case, and repulsion in the second. The
usual method of stating the fact is, that if you face the loop and the
current circulates from left over to right, the N end of the needle
will be drawn into the loop.
[Illustration: Fig. 14b.]
[Illustration: Fig. 14c.]
It thus becomes evident that the loop is equivalent to a flat steel
plate, one surface of which is N and the other S. Facing the loop if
the current is right handed, the S side is toward you.
TO SHOW THE ACTUAL ATTRACTION AND REPULSION OF A MAGNET BY A "MAGNETIC
SHELL."
Produce the field as before (Fig. 14), carry a suspended magnetic
needle over the field. It will tend to place itself parallel to the
lines of force, with the N pole in such a position that, if the
current passes clockwise as you look upon the plane of the loop, it
will be drawn into the loop. Reversing the position of the needle or
of current will show repulsion.
Clerk Maxwell's method of stating the fact is that "every portion of
the circuit is acted on by a force urging it across the lines of
magnetic induction, so as to include a greater number of these lines
within the embrace of the circuit."[2]
[Footnote 2: Electricity and Magnetism, Maxwell, p. 137, §§ 489,
490.]
If the horizontal loop is used (Fig. 14a), the needle tries to
assume a vertical position, with the N or S end down, according to the
direction of the current.
If it is desired to show that if the magnet is fixed and the loop
free, the loop will be attracted or repelled, a special support is
needed.
[Illustration: Fig. 15]
A strip (Fig. 15) of brass, J, having two iron mercury cups, K_{1}
K_{2}, screwed near the ends, one insulated from the strip, is
fastened upon the horizontal arm of the ring support, Fig. 9, already
described. The cups may be given a slight vertical motion for accurate
adjustment. Small conductors (Figs. 16, 17, 18), which are circles,
rectangles, solenoids, etc., may be suspended from the top of the
plate by unspun silk, with the ends dipping into the mercury. The
apparatus is therefore an Ampere's stand, with the weight of the
movable circuit supported by silk and with means of adjusting the
contacts. The rectangles or circles are about two inches in their
extreme dimension. Horizontal and vertical astatic system are also
used--Figs. 18, 18a. The apparatus may be used with either the
horizontal or vertical lantern.
[Illustration: Fig. 16. Fig. 17.]
[Illustration: Fig. 18. Fig. 18a.]
If the rectangle or circle is suspended and a magnet brought near it
when the current passes, the loop will be attracted or repelled, as
the law requires. The experiments usually performed with De la Rive's
floating battery may be exhibited.
The great similarity between the loop and the magnet may be shown by
comparing the fields above (Figs. 14b, 14c) with the actual fields
of two bar magnets, Figs. 19, 19a.
It will be noticed that the lines in Fig. 19, where unlike poles are
opposite, are gathered together as in Fig. 14b,--where the N end of
the magnet faces the S side of the magnetic shell; and that in 19a,
where two norths face, the line of repulsion has the same general
character as in 14c, in which the N end of the magnet faces the N
side of the shell.
[Illustration: Fig. 19.]
[Illustration: Fig. 19a.]
Instead of placing the magnet perpendicular to the plane of the loop,
it may be placed parallel to its plane. Fig. 14d shows the magnet
and loop both vertical.
The field shows that the magnet will be rotated, and will finally take
for stable equilibrium an axial position, with the N end pointing as
determined by the rule already given.
[Illustration: Fig. 14d.]
If two loops are placed with their axes in the same straight line as
follows, Figs. 14f, 14g, a reproduction of Figs. 14b and 14c
will become evident.
It is obvious from these spectra that the two loops attract or repel
each other according to the direction of the current, which fact may
be shown by bringing a loop near to another loop suspended from the
ring stand, Fig. 9, or by using the ordinary apparatus for that
purpose--De la Rive's battery and Ampere's stand.
[Illustration: Fig. 14f.]
[Illustration: Fig. 14g.]
If two loops are placed in the same vertical plane, as in Figs. 14h
and 14i, there will be attraction or repulsion, according to the
direction of the adjacent currents. The fields become the same as
Figs. 8 and 8a, as may be seen by comparing them with those figures.
[Illustration: Fig. 14h.]
[Illustration: Fig. 14i.]
Having thus demonstrated the practical identity of a loop and a
magnet, we proceed to examine the effects produced by loops on
straight wires.
If the loop is placed with a straight wire in its plane along one
edge, there will be attraction or repulsion, according to the
direction of the two currents, Figs. 20 and 20a, which are obviously
the same as Figs. 8 and 8a.
[Illustration: Fig. 20.]
[Illustration: Fig. 20a.]
[Illustration: Fig. 20b.]
[Illustration: Fig. 20c.]
If the wire is placed parallel to the plane of the loop and to one
side, Figs. 20b and 20c, there will be rotation (same as Figs.
4b and 4c).
If the loop is horizontal and the wire vertical and on one side, the
Figs. 20d, 20e are the same as 4d and 4e.
If the loop is horizontal and the wire vertical and axial, 20f and
20g, there will be rotation, and the figures are mere duplicates of
4g and 4h.
[Illustration: Fig. 20d.]
[Illustration: Fig. 20e.]
[Illustration: Fig. 20f.]
[Illustration: Fig. 20g.]
[Illustration: Fig. 20h.]
Fig. 20h shows a view of 20f when the wire is horizontal and the
plane of the loop vertical. It is like 4i.
To verify these facts, suspend a loop from Ampere's stand, Fig. 9, and
bring a straight wire near.
A small rectangle or circle may be hung in a similar manner. When the
circuit is closed, it tends to place itself with its axis in a N and S
direction through the earth's influence. The supposition of an E and W
horizontal earth current will explain this action.
To exemplify rotation of a vertical wire by a horizontal loop, Fig. 21
may be shown.
A circular copper vessel with a glass bottom (Fig. 21) has wound
around its rim several turns of insulated wire. In the center of the
vessel is a metallic upright upon the top of which is balanced in a
mercury cup a light copper [inverted U] shaped strip. The ends of the
inverted U dip into the dilute sulphuric acid contained in the
circular vessel.
The current passes from, the battery, up the pillar, down the legs of
the U to the liquid, thence through the insulated wire back to the
battery.
[Illustration: Fig. 21.]
This is the usual form of apparatus, modified in size for the vertical
or horizontal lantern.
(_To be continued._)
* * * * *
POISONS.
"Poisons and poisoning" was the subject of a discourse a few days ago
at the Royal Institution. The lecturer, Professor Meymott Tidy, began
by directing attention to the derivation of the word "toxicology," the
science of poisons. The Greek word [Greek: toxon] signified primarily
that specially oriental weapon which we call a bow, but the word in
the earliest authors included in its meaning the arrow shot from the
bow. Dioscorides in the first century A.D. uses the word [Greek: to
toxikon] to signify the poison to smear arrows with. Thus, by giving
an enlarged sense to the word--for words ever strive to keep pace, if
possible, with scientific progress, we get our modern and significant
expression toxicology as the science of poisons and of poisoning. A
certain grim historical interest gathers around the story of poisons.
It is a history worth studying, for poisons have played their part in
history. The "subtil serpent" taught men the power of a poisoned fang.
Poison was in the first instance a simple instrument of open warfare.
Thus, our savage ancestors tipped their arrows with the snake poison
in order to render them more deadly. The use of vegetable extracts for
this purpose belongs to a later period. The suggestion is not
unreasonable that if war chemists with their powders, their gun
cotton, and their explosives had not been invented, warlike nations
would have turned for their _instrumenta belli_ to toxicologists and
their poisons. At any rate, the toxicologists may claim that the very
cradle of science was rocked in the laboratory of the toxicological
worker. Early in the history of arrow tipping the admixture of blood
with the snake poison became a common practice. Even the use of animal
fluids alone is recorded--e.g., the arrows of Hercules, which were
dipped in the gall of the Lernæan hydra. Hercules himself at last fell
a victim to the blood stained tunic of the dead Centaur Nessus. As
late as the middle of the last century Blumenbach persuaded one of his
class to drink 7 oz. of warm bullock's blood in order to disprove the
then popular notion that even fresh blood was a poison. The young man
who consented to drink the blood did not die a martyr to science.
The first important question we have to answer is, What do we mean by
a poison? The law has not defined a poison, although it requires at
times a definition. The popular definition of a poison is "a drug
which destroys life rapidly when taken in small quantity." The terms
"small quantity" as regards amount, and "rapidly" as regards time, are
as indefinite as Hodge's "piece of chalk" as regards size. The
professor defined a poison as "any substance which otherwise than by
the agency of heat or electricity is capable of destroying life,
either by chemical action on the tissues of the living body or by
physiological action by absorption into the living system." This
definition excepted from the list of poisons all agencies that
destroyed life by a simple mechanical action, thus drawing a
distinction between a "poison" and a "destructive thing." It explains
why nitrogen is not a poison and why carbonic acid is, although
neither can support life. This point the lecturer illustrated. A
poison must be capable of destroying life. It was nonsense to talk of
a "deadly poison." If a body be a poison, it is deadly; if it be not
deadly, it is not a poison. Three illustrations of the chemical
actions of poisons were selected. The first was sulphuric acid. Here
the molecular death of the part to which the acid was applied was due
to the tendency of sulphuric acid to combine with water. The stomach
became charred. The molecular death of certain tissues destroyed the
general functional rhythmicity of the system until the disturbance
became general, somatic death (that is, the death of the entire body)
resulting. The second illustration was poisoning by carbonic oxide.
The professor gave an illustrated description of the origin and
properties of the coloring matter of the blood, known as _hæmoglobin_,
drawing attention to its remarkable formation by a higher synthetical
act from the albumenoids in the animal body, and to the circumstance
that, contrary to general rule, both its oxidation and reduction may
be easily effected. It was explained that on this rhythmic action of
oxidizing and reducing _hæmoglobin_ life depended.
Carbonic oxide, like oxygen, combined with _hæmoglobin_, produced a
comparatively stable compound; at any rate, a compound so stable that
it ceased to be the efficient oxygen carrier of normal _hæmoglobin_.
This interference with the ordinary action of _hæmoglobin_ constituted
poisoning by carbonic oxide. In connection with this subject the
lecturer referred to the use of the spectroscope as an analytical
agent, and showed the audience the spectrum of blood extracted from
the hat of the late Mr. Briggs (for the murder of whom Muller was
executed), and this was the first case in which the spectroscopic
appearances of blood formed the subject matter of evidence. The third
illustration of poisoning was poisoning by strychnine. Here again the
power of the drug for undergoing oxidation was illustrated. It was
noted that although our knowledge of the precise _modus operandi_ of
the poison was imperfect, nevertheless that the coincidence of the
first fit in the animal after its exhibition with the formation of
reduced _hæmoglobin_ in the body was important.
There followed upon this view of the chemical action of poison in the
living body this question: Given a knowledge of certain properties of
the elements--for example, their atomic weights, their relative
position according to the periodic law, their spectroscopic character,
and so forth--or given a knowledge of the molecular constitution,
together with the general physical and chemical properties of
compounds--in other words, given such knowledge of the element or
compound as may be learned in a laboratory--does such knowledge afford
us any clew whereby to predicate the probable action of the element or
of the compound respectively on the living body? The researches of
Blake, Rabuteau, Richet, Bouchardat, Fraser, and Crum-Brown were
discussed, the results of their observations being that at present we
were unable to determine toxicity or physiological action by any
general chemical or physical researches. The lecturer pointed out that
such relationship was scarcely to be expected. Poisons acted on
different tissues, while even the same poison, according to the dose
administered and other conditions, expended its toxic activity in
different ways.
Further, the allotropic modifications of elements and the isomerism of
compounds increased the difficulties. Why should yellow phosphorus be
an active poison and red phosphorus be inert? Why should piperine be
the poison of all poisons to keep you awake, and morphine the poison
of all poisons to send you asleep, although to the chemist these two
bodies were of identical composition? The lecturer urged that the
science of medicine (for the poisons of the toxicologist were the
medicines of the physician) must be experimental. Guard jealously
against all wanton cruelty to animals; but to deprive the higher
creation of life and health lest one of the lower creatures should
suffer was the very refinement of cruelty. "Are ye not of much more
value then they?" spoke a still small voice amid the noisy babble of
well intentioned enthusiasts.--_London Times._
* * * * *
ARTIFICIAL MOTHER FOR INFANTS.
All the journals have recently narrated the curious story of the
triplets that were born prematurely at the clinic of Assas Street.
Placed at their birth in an apparatus constructed on the principle of
an incubator, in order to finish their development therein, these
frail beings are doing wonderfully well, thanks to the assiduous care
bestowed upon them, and are even showing, it appears, a true emulation
to become persons of importance.
Every one now knows the incubator or "artificial hen"--that box with a
glass top in which, under the influence of a mild heat, hens' eggs,
laid upon wire cloth, hatch of themselves in a few days, and allow
pretty little chicks to make their way out of the cracked shell.
This ingenious apparatus, which has been adopted by most breeders,
gives so good results that it has already supplanted the mother hens
in all large poultry yards, and at present, thanks to it, large
numbers of eggs that formerly ended in omelets are now changing into
chickens.
Although not belonging to the same race, a number of children at their
birth are none the less delicate than these little chicks.
There are some that are so puny and frail among the many brought into
the world by the anæmic and jaded women of the present generation
that, in the first days of their existence, their blood, incapable of
warming them, threatens at every instant to congeal in their veins.
There are some which, born prematurely, are so incapable of taking
nourishment of themselves, of breathing and of moving, that they would
be fatally condemned to death were not haste made to take up their
development where nature left it, in order to carry it on and finish
it. In such a case it is not, as might be supposed, to the
exceptionally devoted care of the mother that the safety of these
delicate existences is confided. As the sitting hen often interferes
with the hatching of her eggs by too much solicitude, so the most
loving and attentive mother, in this case, would certainly prove more
prejudicial than useful to her nursling. So, for this difficult task
that she cannot perform, there is advantageously substituted for her
what is known as an artificial mother. This apparatus, which is
identical with the one employed for the incubation of chickens,
consists of a large square box, supporting, upon a double bottom, a
series of bowls of warm water. Above these vessels, which are renewed
as soon as the temperature lowers, is arranged a basket filled with
cotton, and in this is laid, as in a nest, the weak creature which
could not exist in the open air.
[Illustration: STILL BIRTH WARMING APPARATUS.]
Through the glass in the cover, the mother has every opportunity of
watching the growth of her new born babe; but this is all that she is
allowed to do. The feeding of the infant, which is regulated by the
physician at regular hours, is effected by means of a special rubber
apparatus, through the aid of an intelligent woman who has sole charge
of this essential operation. The aeration of the little being, which
is no less important, is assured by a free circulation, in the box, of
pure warm air, which is kept at a definite temperature and is
constantly renewed through a draught flue. The least variations in the
temperature are easily seen through a horizontal thermometer placed
beneath the glass.
Thus protected against all those bad influences that are often so
fatal at the inception of life, even to the healthiest babes,
preserved from an excess or insufficiency of food, sheltered from cold
and dampness, protected against clumsy handling and against pernicious
microbes, sickly or prematurely born babies soon acquire enough
strength in the apparatus to be able, finally, like others, to face
the various perils that await us from the cradle.
The results that have been obtained for some time back at Paris, where
the surroundings are so unfavorable, no longer leave any doubt as to
the excellence of the process. At the lying-in clinic of Assas Street,
Doctors Farnier, Chantreuil, and Budin succeeded in a few days in
bringing some infants born at six months (genuine human dolls,
weighing scarcely more than from 2¼ to 4½ pounds) up to the normal
weight of 7½ pounds.--_L'Illustration._
* * * * *
GASTROSTOMY.
Surgery has, as is well known, made great progress in recent years.
Apropos of this subject, we shall describe to our readers an operation
that was recently performed by one of our most skillful surgeons, Dr.
Terrillon, under peculiar circumstances, in which success is quite
rare. The subject was a man whose oesophagus was obstructed, and who
could no longer swallow any food, or drink the least quantity of
liquid, and to whom death was imminent. Dr. Terrillon made an incision
in the patient's stomach, and, through a tube, enabled him to take
nourishment and regain his strength. We borrow a few details
concerning the operation from a note presented by the doctor at one of
the last meetings of the Academy of Medicine.
[Illustration: FIG. 1.--FEEDING A PATIENT THROUGH A STOMACHAL TUBE.]
[Illustration: FIG. 2.--DETAILS OF THE TUBE. C, rubber tube for
leading food to the stomach, E; B B', rubber balls, which, inflated
with air by means of the tube, T, and rubber ball, P, effect a
hermetic closing; A, stopper for the tube, C; R, cock of the air
tube.]
Mr. X., fifty-three years of age, is a strong man of arthritic
temperament. He has suffered for several years with violent gastralgia
and obstinate dyspepsia, for which he has long used morphine. The
oesophagal symptoms appear to date back to the month of September,
1887, when he had a painful regurgitation of a certain quantity of
meat that he had swallowed somewhat rapidly.
Since that epoch, the passage of solid food has been either painful or
difficult, and often followed by regurgitation. The food seemed to
stop at the level of the pit of the stomach. So he gave up solid food,
and confined himself to liquids or semi-liquids, which readily passed
up to December 20, 1887. At this epoch, he remarked that liquids were
swallowed with difficulty, especially at certain moments, they
remaining behind the sternum and afterward slowly descending or being
regurgitated. This state of things was more marked especially in the
first part of January. He was successfully sounded several times, but
soon the sound was not able to pass. Doctors Affre and Bazenet got him
to come to Paris, where he arrived February 5, 1888.
For ten days, the patient had not been able to swallow anything but
about a quart of milk or bouillon in small doses. As soon as he had
swallowed the liquid, he experienced distress over the pit of the
stomach, followed by painful regurgitations. For three days, every
attempt made by Dr. Terrillon to remove the obstacle that evidently
existed at the level of the cardia entirely failed. Several times
after such attempts a little blood was brought out, but there was
never any hemorrhage.
The patient suffered, grew lean and impatient, and was unable to
introduce into his stomach anything but a few spoonfuls of water from
time to time. As he was not cachectic and no apparent ganglion was
found, and as his thoracic respiration was perfect, it seemed to be
indicated that an incision should be made in his stomach. The patient
at once consented.
The operation was performed February 9, at 11 o'clock, with the aid of
Dr. Routier, the patient being under the influence of chloroform. A
small aperture was made in the wall of the stomach and a red rubber
sound was at once introduced in the direction of the cardia and great
tuberosity. This gave exit to some yellowish gastric liquid. The tube
was fixed in the abdominal wall with a silver wire. The operation took
three quarters of an hour. The patient was not unduly weakened, and
awoke a short time afterward. He had no nausea, but merely a burning
thirst. The operation was followed by no peritoneal reaction or fever.
Three hours afterward, bouillon and milk were injected and easily
digested.
Passing in silence the technical details, which would not interest the
majority of our readers, we shall be content to say that Mr. X.,
thanks to this alimentation, has regained his strength, and is daily
taking his food as shown in Fig. 1. The aperture made in the stomach
permits of the introduction of the rubber apparatus shown in Fig. 2,
the object of which is to prevent the egress of the liquids of the
stomach and at the same time to introduce food. A funnel is fitted to
the tube, and the liquid or semi-liquid food is directly poured into
the stomach. Digestion proceeds with perfect regularity, and Mr. X.,
who has presented himself, of his own accord, before the Academy, and
whom we have recently seen, has resumed his health and good
spirits.--_La Nature._
* * * * *
HOW TO CATCH AND PRESERVE MOTHS AND BUTTERFLIES.
There is no part of our country in which one cannot form a beautiful
local collection, and any young person who wants amusement,
instruction, and benefit from two, three, or more weeks in the country
can find all in catching butterflies and moths, arranging them, and
studying them up.
Provide yourself first with two tools, a net and a poison bottle. The
net may be made of any light material. I find the thinnest Swiss
muslin best. Get a piece of iron wire, not as heavy as telegraph wire,
bend it in a circle of about ten inches diameter, with the ends
projecting from the circle two or three inches; lash this net frame to
the end of a light stick four or five feet long. Sew the net on the
wire. The net must be a bag whose depth is not quite the length of
your arm--so deep that when you hold the wire in one hand you can
easily reach the bottom with the bottle (to be described) in the other
hand. Never touch wing of moth or butterfly with your fingers. The
colors are in the dusty down (as you call it), which comes off at a
touch. Get a glass bottle or vial, with large, open mouth, and cork
which you can easily put in and take out. The bottles in which
druggists usually get quinine are the most convenient. It should not
be so large that you cannot easily carry it in your pocket. Let the
druggist put in the bottle a half ounce of cyanide of potassium; on
this pour water to the depth of about three-fourths of an inch, and
then sprinkle in and mix gently and evenly enough plaster of Paris to
form a thick cream, which will _set_ in a cake in the bottom of the
vial. Let it stand open an hour to set and dry, then wipe out the
inside of the vial above the cake and keep it corked. This is the
regular entomological poison bottle, used everywhere. An insect put in
it dies quietly at once. It will last several months.
These two tools, the net and the poison bottle, are your catching and
killing instruments. You know where to look for butterflies. Moths are
vastly more numerous, and while equally beautiful, present more
varieties of beauty than butterflies. They can be found by daylight in
all kinds of weather, in the grass fields, in brush, in dark woods,
sometimes on flowers. Many spend the daytime spread out, others with
close shut wings on the trunks of trees in dark woods. The night moths
are more numerous and of great variety. They come around lamps, set
out on verandas in the night, in great numbers. A European fashion is
to spread on tree trunks a sirup made of brown sugar and rum, and
visit them once in a while at night with net and lantern. Catch your
moth in the net, take him out of it by cornering him with the open
mouth of your poison bottle, so that you secure him unrubbed.
Now comes the work of stretching your moths. This is easy, but must be
done carefully. Provide your own stretching boards. These can be made
anywhere with hammer and nail and strips of wood. You want two flat
strips of wood about seven-eighths or three-fourths of an inch thick
and eight to fourteen inches long, nailed parallel to each other on
another strip, so as to leave a narrow open space between the two
parallel strips. Make two or three or more of these, with the slit or
space between the strips of various widths, for large and small moths
and butterflies. Make as many of them, with as various widths of slit,
as your catches may demand. Take your moth by the feet, gently in your
fingers, put a long pin down through his body, set the pin down in the
slit of the stretching board, so that the body of the moth will be at
the top of the slit and the wings can be laid out flat on the boards
on each side. Have ready narrow slips of white paper. Lay out one
_upper_ wing flat, raising it gently and carefully by using the point
of a pin to draw it with, until the lower edge of this upper wing is
nearly at a right angle with the body. Pin it there temporarily with
one pin, carefully, while you draw up the _under_ wing to a natural
position, and pin that. Put a slip of paper over both wings, pinning
one end above the upper and the other below the under wing, thus
holding both wings flat on the stretching board. Take out the pins
first put in the wings and let the paper do the holding. Treat the
opposite wings in the same way. Put as many moths or butterflies on
your stretching board as it will hold, and let them remain in a dry
room for two, three, or more days, according to size of moths and
dampness of climate. Put them in sunshine or near a stove to hasten
drying. When dry, take off the slips of paper, lift the moth out by
the pin through the body, and place him permanently in your
collection.--_Wm. C. Prime, in N.Y. Jour. of Commerce._
* * * * *
THE CLAVI HARP.
The beautiful instrument which we illustrate to-day is the invention
of M. Dietz, of Brussels. His grandfather was one of the first
manufacturers of upright pianos, and being struck with the
difficulties and defects of the harp, constructed, in 1810, an
instrument _à cordes pincées à clavier_--the strings connected with a
keyboard.
Many improvements have from time to time been made on this model,
which at last arrived at the perfection exhibited in the newly
patented clavi harp. The difficulty of learning to play the ordinary
harp, and the inherent inconveniences of the instrument, limit its
use. It is furnished with catgut strings, which are affected by all
the influences of temperature, and require to be frequently tuned. The
necessity of playing the strings with the fingers renders it difficult
to obtain equality in the sounds. It gives only the natural sounds of
the diatonic gamut, and in order to obtain changes of modulation, the
pedals must be employed. Harmonics and shakes are very difficult to
execute on the harp, and--last, but not least--it is not provided with
dampers. The external form of the clavi harp resembles that of the
harp, and all the cords, or strings, are visible. The mechanism which
produces the sound is put into motion directly a key is depressed, and
acts in a similar manner to the fingers of a harpist; the strings
being pulled, not struck. The clavi harp is free from all the
objections inherent in the ordinary harp. The strings are of a
peculiar metal, covered with an insulating material, which has for its
object the production of sounds similar to that obtained from catgut
strings, and to prevent the strings from falling out of tune. The
keyboard, exactly like that of a piano, permits of playing in all
keys, without the employment of pedals. The clavi harp has two pedals.
The first, connected with the dampers, permits the playing of
sustained sounds, or damping them instantaneously. The second pedal
divides certain strings into two equal parts, to give the harmonic
octaves; by the aid of this pedal the performer can produce ten
harmonic sounds simultaneously; on the ordinary harp only four
simultaneous harmonics are possible. An ordinary keyboard being the
intermediary between the performer and the movement of the mechanical
"fingers" which pluck the strings, perfect equality of manipulation is
secured. The mechanical "fingers" instantaneously quit the strings on
which they operate, and are ready for further action. The "fingers"
are covered with suitable material, so that their contact with the
strings takes place with the softness necessary to obtain the most
beautiful tones possible.
[Illustration: THE CLAVI HARP.]
The clavi harp is much lighter than the piano--so that it can easily
be moved from room to room, or taken into an orchestra, by one or two
persons--and is of an elegant form, favorable to artistic decoration.
Sufficient will have been said to give a general idea of the new
instrument.
It is undeniable that at the present day that beautiful instrument,
the harp, is seldom played; still seldomer well played. This is
attributable to the difficulties it presents to pupils. Its seven
pedals must be employed in different ways when notes are to be raised
or lowered a semitone; chromatic passages easy of execution on the
piano are almost impracticable on the harp. The same may be said of
the shake; and it is only after long and exclusive devotion to its
study that the harp can become endurable in the hands of an amateur,
or the means of furnishing a professional harpist with a moderate
income. It is needless to point out how far, in these respects, the
harp is surpassed by the clavi harp.
Vocalists who accompany themselves on the harp are forced, by the
extension of their arms to reach the lower strings, and by frequent
employment of their feet on the pedals, into postures and movements
unfavorable to voice production; but they can accompany themselves
with ease on the clavi harp.
Composers are restricted in the introduction of harp passages in their
orchestral scores, owing to the paucity of harpists. In some cases,
composers have written harp passages beyond the possibility of
execution by a single harpist, and the difficulty and cost of
providing two harpists have been inevitable. These difficulties will
disappear, and composers may give full play to their inspirations,
when the harp is displaced by the clavi harp.--_Building News._
* * * * *
THE ARGAND BURNER.
Argand, a poor Swiss, invented a lamp with a wick fitted into a hollow
cylinder, up which a current of air was permitted to pass, thus giving
a supply of oxygen to the interior as well as the exterior of the
circular frame. At first Argand used the lamp without a glass chimney.
One day he was busy in his work room and sitting before the burning
lamp. His little brother was amusing himself by placing a bottomless
oil flask over different articles. Suddenly he placed it upon the
flame of the lamp, which instantly shot up the long, circular neck of
the flask with increased brilliancy. It did more, for it flashed into
Argand's mind the idea of the lamp chimney, by which his invention was
perfected.
* * * * *
THE SUBTERRANEAN TEMPLES OF INDIA.
During the last fifteen years Bombay has undergone a complete
transformation, and the English are now making of it one of the
prettiest cities that it is possible to see. The environs likewise
have been improved, and thanks to the railways and _bungalows_ (inns),
many excursions may now be easily made, and tourists can thus visit
the wonders of India, such as the subterranean temples of Ajunta,
Elephanta, Nassik, etc., without the difficulties of heretofore.
The excavations of Elephanta are very near Bombay, and the trip in the
bay by boat to the island where they are located is a delightful one.
The deplorable state in which these temples now exist, with their
broken columns and statues, detracts much from their interest. The
temples of Ajunta, perhaps the most interesting of all, are easier of
access, and are situated 250 miles from Bombay and far from the
railway station at Pachora, where it is necessary to leave the cars.
Here an ox cart has to be obtained, and thirty miles have to be
traveled over roads that are almost impassable. It takes the oxen
fifteen hours to reach the bungalow of Furdapore, the last village
before the temples, and so it is necessary to purchase provisions. In
these wild and most picturesque places, the Hindoos cannot give you a
dinner, even of the most primitive character. It was formerly thought
that the subterranean temples of India were of an extraordinary
antiquity.
The Hindoos still say that the gods constructed these works, but of
the national history of the country they are entirely ignorant, and
they do not, so to speak, know how to estimate the value of a century.
The researches made by Mr. Jas. Prinsep between 1830 and 1840 have
enlightened the scientific world as to the antiquity of the monuments
of India. He succeeded in deciphering the Buddhist inscriptions that
exist in all the north of India beyond the Indus as far as to the
banks of the Bengal. These discoveries opened the way to the work done
by Mr. Turnour on the Buddhist literature of Ceylon, and it was thus
that was determined the date of the birth of Sakya Muni, the founder
of Buddhism. He was born 625 B.C. and his death occurred eighty years
later, in 543. It is also certain that Buddhism did not become a true
religion until 300 years after these events, under the reign of Aoska.
The first subterranean temples cannot therefore be of a greater
antiquity. Researches that have been made more recently have in all
cases confirmed these different results, and we can now no longer
doubt that these temples have been excavated within a period of
fourteen centuries.
Dasaratha, the grandson of Aoska, first excavated the temples known
under the name of Milkmaid, in Behar (Bengal), 200 B.C., and the
finishing of the last monument of Ellora, dedicated by Indradyumna to
Indra Subha, occurred during the twelfth century of our era.
[Illustration: FIG. 1.--FACADE OF THE TEMPLE OF PANDU LENA.]
We shall speak first of the temples of Pandu Lena, situated in the
vicinity of Nassik, near Bombay. These are less frequented by
travelers, and that is why I desired to make a sketch of them (Fig. 1).
The church of Pandu Lena is very ancient. Inscriptions have been found
upon its front, and in the interior on one of the pillars, that teach
us that it was excavated by an inhabitant of Nassik, under the reign
of King Krishna, in honor of King Badrakaraka, the fifth of the
dynasty of Sunga, who mounted the throne 129 B.C.
The front of this church, all carved in the rock, is especially
remarkable by the perfection of the ornaments. In these it is to be
seen that the artist has endeavored to imitate in rock a structure
made of wood. This is the case in nearly all the subterranean temples,
and it is presumable that the architects of the time did their
composing after the reminiscences of the antique wooden monuments that
still existed in India at their epoch, but which for a long time have
been forever destroyed. The large bay placed over the small front door
gives a mysterious light in the nave of the church, and sends the rays
directly upon the main altar or _dagoba_, leaving the lateral columns
and porticoes in a semi-obscurity well calculated to inspire
meditation and prayer.
The temples and monasteries of Ajunta, too, are of the highest
interest. They consist of 27 grottoes, of which four only are churches
or _chaityas_. The 23 other excavations compose the monasteries or
_viharas_. Begun 100 B.C., they have remained since the tenth century
of our era as we now see them. The subterranean monasteries are
majestic in appearance. Sustained by superb columns with curiously
sculptured capitals, they are ornamented with admirable frescoes which
make us live over again the ancient Hindoo life. The paintings are
unfortunately in a sad state, yet for the tourist they are an
inexhaustible source of interesting observations.
The excavations, which have been made one after another in the wall of
volcanic rock of the mountain, form, like the latter, a sort of
semicircle. But the churches and monasteries have fronts whose
richness of ornamentation is unequaled. The profusion of the
sculptures and friezes, ornamented with the most artistic taste,
strikes you with so much the more admiration in that in these places
they offer a perfect and varied _ensemble_ of the true type of the
Buddhist religion during this long period of centuries. The
picturesque landscape that surrounds these astonishing sculptures adds
to the beauty of these various pictures.
The temples of Ellora are no less remarkable, but they do not offer
the same artistic _ensemble_. The excavations may be divided into
three series: ten of them belong to the religion of Buddha, fourteen
to that of Brahma, and six to the Dravidian sect, which resembles that
of Jaius, of which we still have numerous specimens in the Indies.
Excavated in the same amygdaloid rock, the temples and monasteries
differ in aspect from those of Ajunta, on account of the form of the
mountain. Ajunta is a nearly vertical wall. At Ellora, the rock has a
gentle slope, so that, in order to have the desired height for
excavating the immense halls of the _viharas_ or the naves of the
_chaityas_, it became necessary to carve out a sort of forecourt in
front of each excavation.
[Illustration: FIG. 2.--PLAN OF THE TEMPLES OF KYLAS.]
Some of the churches thus have their entrance ornamented with
porticoes, and the immense monasteries (which are sometimes three
stories high) with lateral entrances and facades. The mountain has
also been excavated in other places, so as to form a relatively narrow
entrance, which gives access to the internal court of one of these
monasteries. It thus becomes nearly invisible to whoever passes along
the road formed on the sloping side of the mountain. The greatest
curiosity among the monuments of Ellora is the group of temples known
by the name of Kylas (Fig. 2). The monks have excavated the rocky
slope on three faces so as to isolate completely, in the center, an
immense block, out of which they have carved an admirable temple (see
T in the plan, Fig. 2), with its annexed chapels. These temples are
thus roofless and are sculptured externally in the form of pagodas.
Literally covered with sculptures composed with infinite art, they
form a very unique collection. These temples seem to rest upon a
fantastic base in which are carved in alto rilievo all the gods of
Hindoo mythology, along with symbolic monsters and rows of elephants.
These are so many caryatides of strange and mysterious aspect,
certainly designed to strike the imagination of the ancient Indian
population (Fig. 3).
[Illustration: FIG. 3.--SUBTERRANEAN TEMPLE AT ELLORA.]
Two flights of steps at S and S (Fig. 2) near the main entrance of
Kylas lead to the top of this unique base and to the floor of the
temples.
The interior of the central pagoda, ornamented with sixteen
magnificent columns, formerly covered, like the walls, with paintings,
and the central sanctuary that contains the great idol, are composed
with a perfect understanding of architectural proportions.
Exit from this temple is effected through two doors at the sides.
These open upon a platform where there are five pagodas of smaller
size that equal the central temple in the beauty of their sculptures
and the elegance of their proportions.
Around these temples great excavations have been made in the sides of
the mountain. At A (Fig. 2), on a level with the ground, is seen a
great cloister ornamented with a series of bass reliefs representing
the principal gods of the Hindoo paradise. The side walls contain
large, two-storied halls ornamented with superb sculptures of various
divinities. Columns of squat proportions support the ceilings. A small
stairway, X (Fig. 2), leads to one of these halls. Communication was
formerly had with its counterpart by a stone bridge which is now
broken. There still exist two (P) which lead from the floor of the
central temple to the first story of the detached pavilion or
_mantapa_, D, and to that of the entrance pavilion or _gopura_, C. At
G we still see two sorts of obelisks ornamented with arabesques and
designed for holding the fires during religious fetes. At E are seen
two colossal elephants carved out of the rock. These structures, made
upon a general plan of remarkable character, are truly without an
equal in the entire world.
We may thus see how much art feeling the architects of these remote
epochs possessed, and express our wonder at the extreme taste that
presided over all these marvelous subterranean structures.--_A.
Tissandier, in La Nature._
* * * * *
[NATURE.]
TIMBER, AND SOME OF ITS DISEASES.[1]
[Footnote 1: Continued from SUPPLEMENT, No, 640, p. 10222.]
By H. MARSHALL WARD.
IV.
Before proceeding further it will be of advantage to describe another
tree-killing fungus, which has long been well known to mycologists as
one of the commonest of our toadstools growing from rotten stumps and
decaying wood-work such as old water pipes, bridges, etc. This is
_Agaricus melleus_ (Fig. 15), a tawny yellow toadstool with a ring
round its stem, and its gills running down on the stem and bearing
white spores, and which springs in tufts from the base of dead and
dying trees during September and October. It is very common in this
country, and I have often found it on beeches and other trees in
Surrey, but it has been regarded as simply springing from the dead
rotten wood, etc., at the base of the tree. As a matter of fact,
however, this toadstool is traced to a series of dark shining strings,
looking almost like the purple-black leaf stalks of the maidenhair
fern, and these strings branch and meander in the wood of the tree,
and in the soil, and may attain even great lengths--several feet, for
instance. The interest of all this is enhanced when we know that until
the last few years these long black cords were supposed to be a
peculiar form of fungus, and were known as _Rhizomorpha_. They are,
however, the subterranean vegetative parts (mycelium) of the agaric we
are concerned with, and they can be traced without break of continuity
from the base of the toadstool into the soil and tree (Fig. 16). I
have several times followed these dark mycelial cords into the timber
of old beeches and spruce fir stumps, but they are also to be found in
oaks, plums, various conifers, and probably may occur in most of our
timber trees if opportunity offers.
The most important point in this connection is that _Agaricus melleus_
becomes in these cases a true parasite, producing fatal disease in the
attacked timber trees, and, as Hartig has conclusively proved,
spreading from one tree to another by means of the rhizomorphs under
ground. Only the last summer I had an opportunity of witnessing, on a
large scale, the damage that can be done to timber by this fungus.
Hundreds of spruce firs with fine tall stems, growing on the hillsides
of a valley in the Bavarian Alps, were shown to me as "victims to a
kind of rot." In most cases the trees (which at first sight appeared
only slightly unhealthy) gave a hollow sound when struck, and the
foresters told me that nearly every tree was rotten at the core. I had
found the mycelium of _Agaricus melleus_ in the rotting stumps of
previously felled trees all up and down the same valley, but it was
not satisfactory to simply assume that the "rot" was the same in both
cases, though the foresters assured me it was so.
[Illustration: FIG. 15.--A small group of _Agaricus (Armillaria)
melleus_. The toadstool is tawny yellow, and produces white spores;
the gills are decurrent, and the stem bears a ring. The fine hair-like
appendages on the pileus should be bolder.]
By the kindness of the forest manager I was allowed to fell one of
these trees. It was chosen at hazard, after the men had struck a large
number, to show me how easily the hollow trees could be detected by
the sound. The tree was felled by sawing close to the roots; the
interior was hollow for several feet up the stem, and two of the main
roots were hollow as far as we could poke canes, and no doubt further.
The dark-colored rotting mass around the hollow was wet and spongy,
and consisted of disintegrated wood held together by a mesh work of
the rhizomorphs. Further outward the wood was yellow, with white
patches scattered in the yellow matrix, and, again, the rhizomorph
strands were seen running in all directions through the mass.
[Illustration: FIG. 16.--Sketch of the base of a young tree (s) killed
by _Agaricus melleus_, which has attacked the roots, and developed
rhizomorphs at r, and fructifications. To the right the
fructifications have been traced by dissection to the rhizomorph
strands which produced them.]
Not to follow this particular case further--since we are concerned
with the general features of the diseases of timber--I may pass to the
consideration of the diagnosis of this disease caused by _Agaricus
melleus_, as contrasted with that due to _Trametes radiciperda_.
Of course no botanist would confound the fructification of the
_Trametes_ with that of the _Agaricus_; but the fructifications of
such fungi only appear at certain seasons, and that of _Trametes
radiciperda_ may be underground, and it is important to be able to
distinguish such forms in the absence of the fructifications.
The external symptoms of the disease, where young trees are concerned,
are similar in both cases. In a plantation at Freising, in Bavaria,
Prof. Hartig showed me young Weymouth pines (_P. Strobus_) attacked
and killed by _Agaricus melleus_. The leaves turn pale and yellow, and
the lower part of the stem--the so-called "collar"--begins to die and
rot, the cortex above still looking healthy. So far the symptoms might
be those due to the destructive action of other forms of tree-killing
fungi.
On uprooting a young pine, killed or badly attacked by the agaric, the
roots are found to be matted together with a ball of earth permeated
by the resin which has flowed out; this is very pronounced in the case
of some pines, less so in others. On lifting up the scales of the
bark, there will be found, not the silky white, delicate mycelium of
the _Trametes_, but probably the dark cord-like rhizomorphs; there may
also be flat white rhizomorphs in the young stages, but they are
easily distinguished. These dark rhizomorphs may also be found
spreading around into the soil from the roots, and they look so much
like thin roots indeed that we can at once understand their
name--rhizomorph. The presence of the rhizomorphs and (in the case of
the resinous pines) the outflow of resin and sticking together of soil
and roots are good distinctive features. No less evident are the
differences to be found on examining the diseased timber, as
exemplified by Prof. Hartig's magnificent specimens. The wood attacked
assumes brown and bright yellow colors, and is marked by sharp brown
or nearly black lines, bounding areas of one color and separating them
from areas of another color. In some cases the yellow color is quite
bright--canary yellow, or nearly so. The white areas scattered in this
yellow matrix have no black specks in them, and can thus be
distinguished from those due to the _Trametes_. In advanced stages the
purple-black rhizomorphs will be found in the soft, spongy wood.
The great danger of _Agaricus melleus_ is its power of extending
itself beneath the soil by means of the spreading rhizomorphs; these
are known to reach lengths of several feet, and to pass from root to
root, keeping a more or less horizontal course at a depth of six or
eight inches or so in the ground. On reaching the root of another
tree, the tips of the branched rhizomorph penetrate the living cortex,
and grow forward in the plane of the cambium, sending off smaller
ramifications into the medullary rays and (in the case of the pines,
etc.) into the resin passages. The hyphæ of the ultimate twigs enter
the tracheides, vessels, etc., of the wood, and delignify them, with
changes of color and substance as described. Reference must be made to
Prof. Hartig's publications for the details which serve to distinguish
histologically between timber attacked by _Agaricus melleus_ and by
_Trametes_ or other fungi. Enough has been said to show that diagnosis
is possible, and indeed to an expert not difficult.
It is at least clear from the above sketch that we can distinguish
these two kinds of diseases of timber, and it will be seen on
reflection that this depends on knowledge of the structure and
functions of the timber and cambium on the one hand and proper
acquaintance with the biology of the fungi on the other. It is the
victory of the fungus over the timber in the struggle for existence
which brings about the disease; and one who is ignorant of these
points will be apt to go astray in any reasoning which concerns the
whole question. Any one knowing the facts and understanding their
bearings, on the contrary, possesses the key to a reasonable treatment
of the timber; and this is important, because the two diseases
referred to can be eradicated from young plantations and the areas of
their ravages limited in older forests.
Suppose, for example, a plantation presents the following case. A tree
is found to turn sickly and die, with the symptoms described, and
trees immediately surrounding it are turning yellow. The first tree is
at once cut down, and its roots and timber examined, and the diagnosis
shows the presence of _Agaricus melleus_ or of _Trametes radiciperda_,
as the case may be. Knowing this, the expert also knows more. If the
timber is being destroyed by the _Trametes_, he knows that the
ravaging agent can travel from tree to tree by means of roots in
contact, and he at once cuts a ditch around the diseased area, taking
care to include the recently infected and neighboring trees. Then the
diseased timber is cut, because it will get worse the longer it
stands, and the diseased parts burnt. If _Agaricus melleus_ is the
destroying agent, a similar procedure is necessary; but regard must be
had to the much more extensive wanderings of the rhizomorphs in the
soil, and it may be imperative to cut the moat round more of the
neighboring trees. Nevertheless, it has also to be remembered that the
rhizomorphs run not far below the surface. However, my purpose here is
not to treat this subject in detail, but to indicate the lines along
which practical application of the truths of botanical science may be
looked for. The reader who wishes to go further into the subject may
consult special works. Of course the spores are a source of danger,
but need be by no means so much so where knowledge is intelligently
applied in removing young fructifications.
I will now pass on to a few remarks on a class of disease-producing
timber fungi which present certain peculiarities in their biology. The
two fungi which have been described are true parasites, attacking the
roots of living trees, and causing disease in the timber by traveling
up the cambium, etc., into the stem; the fungi I am about to refer to
are termed wound parasites, because they attack the timber of trees at
the surfaces of wounds, such as cut branches, torn bark, frost cracks,
etc., and spread from thence into the sound timber. When we are
reminded how many sources of danger are here open in the shape of
wounds, there is no room for wonder that such fungi as these are so
widely spread. Squirrels, rats, cattle, etc., nibble or rub off bark;
snow and dew break branches; insects bore into stems; wind, hail,
etc., injure young parts of trees, and in fact small wounds are formed
in such quantities that if the fructifications of such fungi as those
referred to are permitted to ripen indiscriminately, the wonder is not
that access to the timber is gained, but rather that a tree of any
considerable age escapes at all.
One of the commonest of these is _Polyporus sulphureus_, which does
great injury to all kinds of standing timber, especially the oak,
poplar, willow, hazel, pear, larch, and others. It is probably well
known to all foresters, as its fructification projects horizontally
from the diseased trunks as tiers of bracket-shaped bodies of a
cheese-like consistency; bright yellow below, where the numerous
minute pores are, and orange or somewhat vermilion above, giving the
substance a coral-like appearance. I have often seen it in the
neighborhood of Englefield Green and Windsor, and it is very common in
England generally.
If the spore of this _Polyporus_ lodges on a wound which exposes the
cambium and young wood, the filaments grow into the medullary rays and
the vessels and soon spread in all directions in the timber,
especially longitudinally, causing the latter to assume a warm brown
color and to undergo decay. In the infested timber are to observed
radial and other crevices filled with the dense felt-like mycelium
formed by the common growth of the innumerable branched filaments. In
bad cases it is possible to strip sheets of this yellowish white felt
work out of the cracks, and on looking at the timber more closely (of
the oak, for instance), the vessels are found to be filled with the
fungus filaments, and look like long white streaks in longitudinal
sections of the wood--showing as white dots in transverse sections.
It is not necessary to dwell on the details of the histology of the
diseased timber; the ultimate filaments of the fungus penetrate the
walls of all the cells and vessels, dissolve and destroy the starch in
the medullary rays, and convert the lignified walls of the wood
elements back again into cellulose. This evidently occurs by some
solvent action, and is due to a ferment excreted from the fungus
filaments, and the destroyed timber becomes reduced to a brown mass of
powder.
I cannot leave this subject without referring to a remarkably
interesting museum specimen which Prof. Hartig showed and explained to
me last summer. This is a block of wood containing an enormous
irregularly spheroidal mass of the white felted mycelium of this
fungus, _Polyporus sulphureus_. The mass had been cut clean across,
and the section exposed a number of thin brown ovoid bodies embedded
in the closely woven felt; these bodies were of the size and shape of
acorns, but were simply hollow shells filled with the same felt-like
mycelium as that in which they were embedded. They were cut in all
directions, and so appeared as circles in some cases. These bodies
are, in fact, the outer shells of so many acorns, embedded in and
hollowed out by the mycelium of _Polyporus sulphureus_. Hartig's
ingenious explanation of their presence speaks for itself. A squirrel
had stored up the acorns in a hollow in the timber, and had not
returned to them--what tragedy intervenes must be left to the
imagination. The _Polyporus_ had then invaded the hollow, and the
acorns, and had dissolved and destroyed the cellular and starchy
contents of the latter, leaving only the cuticularized and corky
shells, looking exactly like fossil eggs in the matrix. I hardly think
geology can beat this for a true story.
The three diseases so far described serve very well as types of a
number of others known to be due to the invasion of timber and the
dissolution of the walls of its cells, fibers, and vessels by
hymenomycetous fungi, i.e., by fungi allied to the toadstools and
polypores. They all "rot" the timber by destroying its structure and
substance, starting from the cambium and medullary rays.
To mention one or two additional forms, _Trametes Pini_ is common on
pines, but, unlike its truly parasitic ally, _Tr. radiciperda_, which
attacks sound roots, it is a wound parasite, and seems able to gain
access to the timber only if the spores germinate on exposed surfaces.
The disease it produces is very like that caused by its ally; probably
none but an expert could distinguish between them, though the
differences are clear when the histology is understood.
_Polyporus fulvus_ is remarkable because its hyphæ destroy the middle
lamella, and thus isolate the tracheides in the timber of firs;
_Polyporus borealis_ also produces disease in the timber of standing
conifers; _Polyporus igniarius_ is one of the commonest parasites on
trees such as the oak, etc., and produces in them a disease not unlike
that due to the last form mentioned; _Polyporus dryadeus_ also
destroys oaks, and is again remarkable because its hyphæ destroy the
middle lamella.
With reference to the two fungi last mentioned I cannot avoid
describing a specimen in the Museum of Forest Botany in Munich, since
it seems to have a possible bearing on a very important question of
biology, viz., the action of soluble ferments.
It has already been stated that some of these tree-killing fungi
excrete ferments which attack and dissolve starch grains, and it is
well known that starch grains are stored up in the cells of the
medullary rays found in timber. Now, _Polyporus dryadeus_ and _P.
igniarius_ are such fungi; their hyphæ excrete a ferment which
completely destroys the starch grains in the cells of the medullary
rays of the oak, a tree very apt to be attacked by these two
parasites, though _P. igniarius_, at any rate, attacks many other
dicotyledonous trees as well. It occasionally happens that an oak is
attacked by both of these polyporei, and their mycelia become
intermingled in the timber; when this is the case, the _starch grains
remain intact in those cells which are invaded simultaneously by the
hyphæ of both fungi_. Prof. Hartig lately showed me longitudinal
radial sections of oak timber thus attacked, and the medullary rays
showed up as glistening white plates. These plates consist of nearly
pure starch; the hyphæ have destroyed the cell walls, but left the
starch intact. It is easy to suggest that the two ferments acting
together exert (with respect to the starch) a sort of inhibitory
action one on the other; but it is also obvious that this is not the
ultimate explanation, and one feels that the matter deserves
investigation.
It now becomes a question--What other types of timber diseases shall
be described? Of course the limits of a popular article are too narrow
for anything approaching an exhaustive treatment of such a subject,
and nothing has as yet been said of several other diseases due to
crust-like fungi often found on decaying stems, or of others due to
certain minute fungi which attack healthy roots. Then there is a class
of diseases which commence in the bark or cortex of trees, and extend
thence into the cambium and timber: some of these "cankers," as they
are often called, are proved to be due to the ravages of fungi, though
there is another series of apparently similar "cankers" which are
caused by variations in the environment--the atmosphere and weather
generally.
It would need a long article to place the reader _au courant_ with the
chief results of what is known of these diseases, and I must be
content here with the bare statement that these "cankers" are in the
main due to local injury or destruction of the cambium. If the normal
cylindrical sheet of cambium is locally irritated or destroyed, no one
can wonder that the thickening layers of wood are not continued
normally at the locality in question; the uninjured cells are also
influenced, and abnormal cushions of tissue formed, which vary in
different cases. Now, in "cankers" this is--put shortly--what happens:
it may be, and often is, due to the local action of a parasitic
fungus; or it may be, and, again, often is, owing to injuries produced
by the weather, in the broad sense, and saprophytic organisms may
subsequently invade the wounds.
The details as to how the injury thus set up is propagated to other
parts--how the "canker" spreads into the bark and wood around--_are_
details, and would require considerable space for their description:
the chief point here is again the destructive action of mycelia of
various fungi, which by means of their powers of pervading the cells
and vessels of the wood, and of secreting soluble ferments which break
down the structure of the timber, render the latter diseased and unfit
for use. The only too well known larch disease is a case in point; but
since this is a subject which needs a chapter to itself, I may pass on
to more general remarks on what we have learned so far.
It will be noticed that, whereas such fungi as _Trametes radiciperda_
and _Agaricus melleus_ are true parasites which can attack the living
roots of trees, the other fungi referred to can only reach the
interior of the timber from the exposed surfaces of wounds. It has
been pointed out along what lines the special treatment of the former
diseases must be followed, and it only remains to say of the latter:
take care of the cortex and cambium of the tree, and the timber will
take care of itself. It is unquestionably true that the diseases due
to wound parasites can be avoided if no open wounds are allowed to
exist. Many a fine oak and beech perishes before its time, or its
timber becomes diseased and a high wind blows the tree down, because
the spores of one of these fungi alight on the cut or torn surface of
a pruned or broken branch. Of course it is not always possible to
carry out the surgical operations, so to speak, which are necessary to
protect a tree which has lost a limb, and in other cases no doubt
those responsible have to discuss whether it costs more to perform the
operations on a large scale than to risk the timber. With these
matters I have nothing to do here, but the fact remains that by
properly closing over open wounds, and allowing the surrounding
cambium to cover them up, as it will naturally do, the term of life of
many a valuable tree can be prolonged, and its timber not only
prevented from becoming diseased and deteriorating, but actually
increased in value.
There is no need probably for me to repeat that, although the present
essay deals with certain diseases of timber due to fungi, there are
other diseases brought about entirely by inorganic agencies. Some of
these were touched upon in the last article, and I have already put
before the readers of _Nature_ some remarks as to how trees and their
timber may suffer from the roots being in an unsuitable medium.
In the next paper it is proposed to deal with the so-called "dry rot"
in timber which has been felled and cut up--a disease which has
produced much distress at various times and in various countries.
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