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Title: Salt and the salt industry
Author: Calvert, Albert Frederick
Language: English
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*** Start of this LibraryBlog Digital Book "Salt and the salt industry" ***
INDUSTRY ***
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Italics are indicated with _underscores_, boldface with =equals signs=,
and superscripts with ^{text} or ^text.
[Illustration: VIEW OF THE COMMERCIAL SALT COMPANY’S BRINE RESERVOIRS
AT RODE HEATH, CHESHIRE,
Showing the Brine being pumped up from a depth of 250 feet
_Frontispiece_
]
PITMAN’S COMMON COMMODITIES
AND INDUSTRIES
SALT
AND THE
SALT INDUSTRY
BY
ALBERT F. CALVERT, F.C.S.
AUTHOR OF “SALT IN CHESHIRE”;
“THE SALT DEPOSITS OF THE WORLD”; ETC.
LONDON
SIR ISAAC PITMAN & SONS, LTD., 1 AMEN CORNER, E.C.4
BATH, MELBOURNE AND NEW YORK
PRINTED BY SIR ISAAC PITMAN
& SONS, LTD., LONDON, BATH,
MELBOURNE AND NEW YORK
PREFACE
The fact that salt is almost universally distributed over the surface
of the globe, and has been worked in a number of countries from time
immemorial, will explain the impossibility, in the limited space at my
disposal, to consider the mineral and its manufacture comprehensively
as the staple of a world-industry. The salt deposits of China, India,
Russia, Japan, and Austria would each require a volume of the size
of this if the subject was to be even adequately represented. I
have, therefore, dared to assume that the public will accept a book
practically restricted to one phase of the matter, and allow me to
concentrate upon our Cheshire salt district and its industry.
Caesar’s _salinators_, who found the natives of Cheshire procuring
brine from little natural springs in the neighbourhoods of Northwich
and Nantwich, taught them to boil the brine and precipitate the salt
crystals in open pans set over open fires, and in the following 1,700
years all the salt of Cheshire was manufactured by that process.
With the discovery of rock salt in 1670, mining was introduced, and
for another 200 years both rock salt and brine salt were produced.
But from causes which I have described, the mines collapsed in rapid
succession from about the middle of the nineteenth century, and fresh
water breaking into the abandoned workings converted them into the
brine reservoirs from which the salt-men have since obtained their
inexhaustible supplies of brine.
But, although the salt industry is one of the oldest in the country,
it has received scant treatment at the hands of authors, and this is
accounted for by the fact that the trade has been conducted by a
comparatively small group of men who have resisted all attempts of
outsiders to participate in either their secrets or their profits. The
desire for information has been consistently rebuked, and practical
details relating to borings, working expenses, levels of brine, and
quantities raised have been jealously concealed. It was my good fortune
to be able to prosecute most of my researches on the spot, and to
supplement the knowledge gained from books, pamphlets, scientific
papers and periodicals, with material contained in private records and
documents placed at my disposal, and information obtained by word of
mouth.
There is romance in every industry, and a modicum of it enters into
the development of the Cheshire salt trade; but for the most part the
story is a chronicle of bitter struggles to maintain a monopoly, of
money thrown away, of produce sold at ruinous loss, of obsolete methods
stubbornly persisted with, and of hardship and injustice callously
inflicted--in a word, of the sordid determination of the salt magnates
to crush competition and control prices. The methods of the Dark Ages
survived both in the manufacture and the marketing of the produce, and
the industry has more than once been reduced almost to ruin through
the war of extermination in which for so many years the salt-men were
engaged. It is not a pretty story, but it is one of unusual interest;
and I have endeavoured in the telling of it to retain the interest and
preserve the essential facts.
ALBERT F. CALVERT.
ROYSTON,
ETON AVENUE, N. W.
CONTENTS
CHAP. PAGE
PREFACE iii
I. THE CHEMISTRY AND PROPERTIES OF SALT 1
II. THE BEGINNINGS OF THE SALT INDUSTRY 8
III. THE CHESHIRE WICHES 32
IV. DEVELOPMENT OF BRINE PROCESSES 56
V. FORMATION AND EXTENT OF THE CHESHIRE DEPOSITS 83
VI. THE CHESHIRE SUBSIDENCES 97
VII. LATEST METHODS OF SALT-MAKING 125
VIII. THE SALT MARKET 142
ILLUSTRATIONS
PAGE
VIEW OF THE COMMERCIAL SALT COMPANY’S BRINE RESERVOIRS AT RODE
HEATH, CHESHIRE _Frontispiece_
ANCIENT SALT WORKS 13
ANCIENT SALT WORKS 19
WIELIEZKA SALT MINES 21
SLANICU, RUMANIA, INTERIOR OF SALT MINE 25
WIELIEZKA SALT MINES 29
SUBSIDENCE OF LAND, NORTHWICH 41
DUNKIRK SUBSIDENCE, NORTHWICH 49
THE CANAL-BURST AND LANDSLIP NEAR NORTHWICH IN 1907 59
A SALT STORE-SHED 67
WITTON BROOK, SUBMERGENCE OF AGRICULTURAL LAND 75
WORKING IN DANGEROUS GROUND AFTER SUBSIDENCE, DUNKIRK LAKE,
NORTHWICH 81
STREET-RAISING IN PROGRESS--HIGH STREET, NORTHWICH 89
THIS ROAD WAS RAISED TWENTY FEET IN TWENTY YEARS. NONE OF
THESE BUILDINGS IS NOW STANDING--NORTHWICH 93
INTERIOR PENNY’S LANE MINE, NORTHWICH 99
REMARKABLE SUBSIDENCE IN NORTHWICH 111
A ROW OF OPEN PANS 119
ILLUSTRATION OF FOUR SCOTT PATENT DOUBLE EFFECT SALT
EVAPORATORS, WITH AUTOMATIC SALT DISCHARGERS, SALT
CONVEYORS, AND HYDRO-EXTRACTORS 131
THE HODGKINSON PATENT SALT-MAKING PLANT 137
SALT AND THE SALT INDUSTRY
CHAPTER I
THE CHEMISTRY AND PROPERTIES OF SALT
“Salt” was the name which was given in the first place to the residue
left by the evaporation of sea-water, but the designation was
subsequently employed to include the other substances held in solution
in the sea, and, at a still later period, the name was still further
extended by chemists to cover all the combinations of a base and an
acid which are now classed as “salts.” Sodium, or sodic chloride Na Cl,
which is now distinguished as “common salt,” is an example of the
simplest type of chemical salt, its molecule consisting of one atom
of the metal sodium combined with one atom of the gas chlorine, both
sodium and chlorine being mono-valent elements, _i.e._, one atom of
each being able to unite with, or displace from a compound, one atom of
hydrogen.
Rock-salt is rarely found in an absolutely pure anhydrous state, in
which it is colourless and perfectly transparent. In most rock-salt
mines such specimens are regarded as curiosities, but in the deposits
of Nevada and of Wieliezka, in Hungary (where the salt, containing
100 per cent. NaCl, is the purest in the world), large masses of
quite transparent salt are encountered. The white opaque mass which
the ordinary person is accustomed to think of as rock-salt, is the
purified product of commerce. The colour of sea-water is affected by
its percentage of salt, the colour changing from blue to green as the
quantity of salt decreases; but sea-salt is generally white, although
not transparent owing to the presence of minute particles of water,
air, etc., in its intercrystalline spaces. But rock-salt is never more
than whitish inclining to grey, and, as a general rule, it is coloured
by earth or mineral impurities. The Salt Range in the Panjab yields
a substance that varies from pink to red, according to the different
quantities of iron present as impurities. That found at Marston, in
Cheshire, varies from yellow to red and brownish-red in colour. Small
blocks of transparent salt of a deep sapphire blue are occasionally
found in the Wieliezka mines. The colour disappears on heating, and
when the salt is ground to powder. It is attributed by some chemists
to the presence of subchloride of sodium, by others to the presence of
thin cavities having parallel surfaces with gas inclusions.
Common salt, which is classed as “sweet” to distinguish it from the
bitter-tasting salts of magnesium, has a peculiar saline taste which
gains in pungency with refinement, and in its pure state is odourless.
In solution, the smallest quantity perceptible to the taste is about 15
grains to the litre, roughly, 68 grains to the gallon.
Common salt is highly soluble in cold water, and rather more so in hot
water, but while it dissolves slightly in alcohol, neither ether nor
oil has any effect upon it. One hundred parts of distilled water at
60° F. (15·5° C.) will dissolve 35·9 parts of chemically pure NaCl. A
saturated solution of common salt, therefore, contains 26·42 per cent.
NaCl. The increase of solubility of NaCl in proportion to the rise in
temperature, calculated by Gay Lussac and Poggiale, is particularly
marked between 100 deg. and 110 deg., when boiling point is passed,
the increase amounting to ·74 parts of 10 deg., as compared with an
increase of one 1·09 parts between freezing and boiling points. In a
double solution of NaCl and some other more soluble salt, as sodium
or magnesium sulphate or magnesium chloride, the solubility of sodium
chloride is very greatly reduced.
The evaporation of brine is slightly less rapid than that of ordinary
pure water, and the boiling point of brine varies with the amount of
NaCl present in solution, from 100·21 deg. when only 1 per cent. NaCl
is present, to 108·99 deg. when the solution contains 29·4 per cent. of
NaCl. A saturated solution of refined table-salt (_i.e._, a solution
containing 26·4 per cent. NaCl) has, at normal temperatures, specific
gravity 1·2. Salt crystals have specific gravity 2·167 at a temperature
of 17°. The salt which separates at high temperature contains no water
of crystallization. But when the thermometer falls much below -15° C.
the crystals have the composition NaCl.2H₂O and are prismatic in shape.
When heated, these give up their water of crystallization and take the
simple composition NaCl.
Pure sodium chloride is not deliquescent (_i.e._, it does not dissolve
and become liquid by absorbing moisture from the air), but, owing
to the presence of minute quantities of magnesium chloride (one of
the most deliquescent substances known), all except the most refined
table-salt appears to be so to a slight extent. Even the finest
table-salt is slightly hygroscopic, its crystals absorbing as much as
·6 per cent. moisture from a damp atmosphere. In some of the mines of
Cheshire and Austria the very fine saline dust that is diffused through
the atmosphere is found by the miners to be extremely irritating to the
eyes and lungs, but all the more usual kinds of salt are sufficiently
hygroscopic to indicate plainly the condition of the atmosphere.
Sodic chloride melts at a very high temperature, and at a still higher
temperature it evaporates, while at white heat it forms thick clouds.
It would be supposed that in the same ocean areas, the proportion of
the salt contents, except where marked differences in temperature
occur, would be fairly constant, but it has been demonstrated that,
even where masses of water of varying densities are superimposed upon
each other, no very complete process of diffusion takes place between
them, and practical salt-makers are familiar with differences in
density which occur in different parts of the same salt pan.
The hardness of a mineral depends upon the degree of cohesion of its
particles; but although no unit of hardness has been determined upon,
and therefore no accurate method of measuring hardness has been arrived
at, minerals have been approximately classed in a comparative table
of ten substances, of which talc is placed at one end and diamond at
the other. In this table, rock salt appears in the second place, and
its hardness is estimated at 2·5. Its cohesion or power of supporting
pressure is, therefore, about twice as great as that of bricks, and the
practical advantage of this property is fully employed in rock-salt
mines, where galleries and roofs are supported upon pillars of salt.
Common salt is a crystalline substance which crystallizes in the
Isometric, Monometric, or Tesseral system. That is to say, each crystal
has three equal perpendicular planes of symmetry and six equal diagonal
planes of symmetry. The crystals generally form cubes having six
rectangular and equilateral faces. When these form on the surface of
brine the sides often collapse, giving the distinctive “hopper-shaped”
forms. More rarely the crystals form in octahedra, having eight
equal, equilateral triangular faces, or in long needles under certain
modifying conditions.
The hollow quadrangular pyramidal form with an irregular inner
surface arranged in steps, which manufactured salt generally takes,
is the result of continuous depositions of crystals from a constantly
saturated solution of brine during a considerable period, being
superimposed layer after layer upon each other.
In his exhaustive explanation of these phenomena, given in his
_Principles of Chemistry_, Mendeléeff says: “If a solution of sodium
chloride be slowly heated from above, where the evaporation takes
place, the upper layer will become saturated before the lower and
cooler layers, and therefore crystallization will begin on the surface,
and the crystals first formed will float--having also dried from
above--on the surface until they become quite soaked. Being heavier
than the solution the crystals are partially immersed in it, and the
following crystallization, also proceeding on the surface, will only
form crystals by the side of the original crystals. A funnel is formed
in this manner. It will be borne on the surface like a boat (if the
liquid be quiescent) because it will grow more from the upper edges.
We can thus understand this, at first sight, strange funnel-form of
crystallized salt. To explain why the crystallization under the above
conditions begins at the surface and not at the lower edges, it must
be mentioned that the specific gravity of a crystal of sodium chloride
is 2·16, and that a solution saturated at 25° contains 26·7 per cent.
of salt and has a specific gravity 1·2004 at 25°; at 15° a saturated
solution contains 26·5 per cent. of salt and has a specific gravity
1·203 at 15°. Hence, a solution saturated at a higher temperature
is specifically lighter, notwithstanding the greater amount of salt
it contains. With many substances, surface crystallization cannot
take place, because their solubility increases more rapidly with the
temperature than their specific gravity decreases. In this case the
saturated solution will always be in the lower layers, where also the
crystallization will take place.”
The acoustic properties of common salt render it an excellent medium
for the transmission of sound, and as it possesses in a high degree the
power of staying decomposition in dead organisms, it is, perhaps, the
commonest of all preservatives. It is largely owing to its preservative
property that common salt is an absolute necessity to the life of man
and the higher animals, from a quarter to half an ounce a day being
sufficient to prevent the putrefaction of food in the digestive tract
in the case of an adult. In agriculture, salt is not only valuable
as a destroyer of weeds and insect life, but used sparingly and with
knowledge, it forms an excellent manure; while its more strictly
chemical value in the manufacture of soda, chlorine, etc., causes it to
play an important part in many branches of industry.
Even at the highest temperatures, heat cannot effect the decomposition
of common salt. At a red heat, pure sodic chloride melts and becomes
liquid, and if cooled again, a solid crystalline mass is formed.
Ordinary salt fuses at a lower temperature and volatilizes when heated
in an open vessel. But even in a closed vessel the purest salt will
volatilize at a white heat. When gases or fluids are present in the
crystalline cavities, heat causes decrepitation.
On the subject of the composition of brine, it is only necessary to add
that it is so extremely variable that no two districts produce brine
springs of the same strength and density, while the composition of
ocean brine varies not only from ocean to ocean, but also for different
parts and different depths in the same plane of water, and with the
different distances from the mouths of large rivers. In the Cheshire
district, the Brine test or Salinometer is graduated to show ounces in
the gallon; but the gallon is the old Winchester Gallon of 231 cub. in.
and not the Imperial Gallon of 277·274 cub. in. These are related to
each other in the proportion of 10 to 12, therefore the Imperial Gallon
will contain ⅕ more than the old gallon. Fully saturated brine by the
Salinometer contains 42 oz. (2 lb. 10 oz.), therefore, in the Imperial
Gallon 50·4 oz. As brines vary from 2 lb. 8 oz., or 40 oz. old measure,
or 3 lb. or 48 oz. Imperial to 2 lb. 10 oz., or 3 lb. 2 oz. Imperial,
so 1,000 gallons, which has been chosen as the measure for assessing
brine-pumpers--under the Brine Pumping Compensation for Subsidence Act
of 1891--will contain under the old measurement 2,625 lb. and under the
Imperial 3,125 lb. of salt.
CHAPTER II
THE BEGINNINGS OF THE SALT INDUSTRY
Salt, being existent in all animal and vegetable life, is coeval with
life itself; it was present in the first herbage which gave nourishment
to the first beast that, in its turn, became food for the first
omnivorous man. In the beginning, man consumed the saline essences
that were required to preserve his body in health, in the form of
sodium chloride, which he absorbed in the uncooked flesh of animals,
birds, and fishes, and in raw green-foods. The herbivorous animals were
equally dependent upon salt, and, finding it in only infinitesimal
quantities in the grasses upon which they fed, instinct directed them
to the sea swamp pasturage and to the outcropping salt deposits. So
long as man’s diet consisted of uncooked foods, his fresh meat provided
him with a sufficiency of salt, but directly he employed a cook-pot
in the preparation of his food, the boiling processes denuded it of
70 per cent. of its natural salt, and it became necessary for him to
make up the deficiency. It must have been at this period that his herds
directed his attention to the “salt licks” from which they satisfied
their own saline wants, and enabled him to secure salt as a distinct
and separate condiment.
It is probable that, from the Palaeolithic Age down to the time of the
early Roman writers, man was content to season his victuals by the
simple process of licking a piece of rock-salt, and we have no record
to indicate the period when salt was first employed in the cooking of
food. From varieties of grain and fragments of pottery that have been
discovered in the dwellings of the cave-men of Belgium, it is supposed
that salt was employed in the cooking of wheat and barley some five
thousand years ago. Thirteen centuries before Christ, fish preserved
in salt was eaten in Ancient Troy, and, according to Herodotus, the
Egyptians not only salted ducks, quails, and a species of sardine which
inhabited the Nile, but also employed salt or brine as an antiseptic
in preparing the bodies of the illustrious dead for the process of
embalming.
We cannot determine the period in which salt came to be regarded as
a symbol of sanctity or entered into the religious ceremonials of
the ancients. We know that in the Levitical Law, promulgated in 1500
B.C., every meat-offering was seasoned with salt, and salt is referred
to in the “Verbal Instructions” which were enunciated by the founder
of Buddhism, five centuries later. By the time of Pythagoras, about
600 B.C., salt was regarded as the emblem of justice, but who shall
say when the Arabs first employed it as a token of friendship, or
the Chinese offered their first oblation to Phelo, the salt deity of
Celestial worship? We read in Herodotus that caravans brought salt
from North Africa, and Schleiden tells us that the priests of Egypt
preferred the salt of Hammomen to that evaporated from sea-water; but
these references do not help us to fix the date when salt became an
article of commerce, or tell us when or where or by whom it was first
produced in a manufactured form. It was rock-salt which the Egyptians
procured from the salt basin of the Sahara, and rock-salt from the
margin of the Red Sea was the variety that is referred to by the
compilers of Biblical history. But, although the natural crude product
was probably the sole form in which it was known in the Western world
by the Ancients, and through the vaunted golden epochs of Babylon,
Byzantium, and Greece, the Chinese--who had invented explosives before
the Romans had perfected the catapult, and had learnt to navigate by
the compass while yet the mariners of the Mediterranean were dependent
upon the stars and their wits--had probably been familiar for ages
with a salt manufactured by a process, the origin of which they had
forgotten, but the practice of which was to remain in operation, almost
without revision, for further thousands of years.
The first mention of salt in the Chinese language is found in the
annals of the Emperor Yu (2205–2197 B.C.), who ordered the province
of Shantung to supply the Court with that commodity. During the Chow
dynasty (1122–249 B.C.) the administration of the salt industry was
conducted by Court officials, but the Crown monopoly of salt was not
instituted until the days of Kuan Chung, who died 645 B.C. Between A.D.
561 and A.D. 583, references to various taxes on salt lead us to the
conclusion that salt was produced at that period from sea-water, salt
marshes, and salt springs, and at the present day salt is produced
in China in three varieties--sea-salt, lake-salt, and well-salt. As
the success of the boiling operation (which antedated by unnumbered
centuries the comparatively modern industry of extracting salt from
sea-water by evaporation in the sun) depends mainly on the condition
of the brine and the time allowed in each stage of the process,
the details were the subject of many series of experiments in the
pursuit of the perfect system, but since about the twelfth century
the following method has been consistently followed by the Chinese
salt-makers. The whole of the sea-shore in the neighbourhood of the
salt works is measured out and divided into a number of small, regular
squares; the surface layer in each is dug out; the bottom of each pit
thus formed is then strewn with straw, and the earth that has been
removed is thrown back upon it. When these brine ovens, as they were
called--which are shaped like chests, 9 ft. long, 2 ft. broad, and 3
ft. deep--are prepared, they are soaked with sea-water. The sea-water
in the interior of the ovens forms brine, and flows through little
ditches into wells which have been dug for its reception. From these
wells, which are about 8 ft. deep, the brine is drawn out and carried
to the boiling ovens. These brine ovens are furnished with large
evaporating pans, three to five of which are attached to each oven. The
boiling takes place at once and is continued without interruption, from
11 p.m. until 10.30 on the following morning, and during this period
the salt is taken out six times. As soon as the salt begins to harden,
pods of the _tsao-chio_ tree are thrown into the pans, in order that
the particles of salt may combine more quickly, and as soon as it is
precipitated, it is removed and the pans are refilled with fresh brine.
On an average, 600 cathés of the best brine yield 140 cathés of pure
salt, which is produced in three qualities and colours--white, dark,
and yellow. The white is the best, the dark is less esteemed, and the
yellow, which is much inferior, has a bitter taste.
Since the fifteenth century, the Chinese have produced salt by solar
evaporation of salt water, according to a simple but satisfactory
process. Pits are dug on the sea-shore and bamboos are laid crosswise
over them. The whole is covered with double mats, and sand is strewn
over the top. Every morning and evening the covering of sand is soaked
with sea-water by the tide, and the salt liquor finds its way into
the pits. As soon as the water has receded, the salt workers appear
with flaming bundles of straw, to test the saline character of the
moisture, which is not regarded as fully impregnated unless the salt
vapour arising from the pits extinguishes the fire. The brine thus
produced is drawn off and run into secondary or crystallizing ponds,
the level of which is set a foot or so below the first series of pits.
The secondary ponds, which are smaller and of less depth, are provided
with carefully-rolled, hard clay bottoms. When a sufficiently thick
crystalline deposit has been formed at the bottom of the secondary
ponds, workmen, starting at the centre, scrape the bottoms, working
outward spirally and finishing at the corner of the pond, where the
coarse crystalline product is collected and allowed to drain. When
drained and dried, the salt is ready for transfer to the market.
In Japan, where the manufacture of sea-salt by boiling or by
spontaneous evaporation was introduced more than two thousand years
ago, the process is similar to that employed in China, but in some
parts of the kingdom the evaporation basin generally employed in solar
evaporation is dispensed with. In the latter method, a level field is
formed close to the sea and sprinkled over with fine sand. Sea-water
is then poured into the field, and, after evaporation of the water,
the salt crystallizes and adheres to the sand. The mixture of salt and
sand is next thrown into a kind of extracting apparatus and sea-water
is poured upon it, whereupon the salt is dissolved and filtered in
the form of a thick salt liquid. In other Japanese salt fields the
concentrated liquor is poured into a crystallization basin prepared for
the purpose, and, upon evaporation of the water by the sun’s heat, the
salt crystallizes.
[Illustration: ANCIENT SALT WORKS
_A._ Wooden Ladle. _B._ Cask. _C._ Tub. _D._ The Master.
_E._Assistant. _F._ The Master’s Wife. _G._ Wooden Spade.
_H._ Boards. _I._ Salt-baskets. _K._ Hoe. _L._ Rake. _M._ Straw.
_N._ Bowls. _O._ Bucket for Blood. _P._ Beer Tankard.
_From an Old Print_ _Published in 1556_·
]
In Italy most of the salt is made by solar evaporation. The salt
grounds, which occupy extensive areas, are furnished with reservoirs
for the preparation of the sea-water by saturation and for the
deposit of salt. The former are known as condensers and the latter
as crystallizing beds, and in both the work is carried on by solar
evaporation only. Every salt-ground, or salt-garden, as it is called,
has a feeding channel for the inflow of sea-water, a drainage channel,
and a network of internal channels at low and high levels, as are
required for immission or drainage purposes. In Portugal and Spain,
salt is made by solar evaporation from sea-water, and although there
are differences between the several methods, they apply only to details
regarding the areas of the salt-grounds or the sizes of the reservoirs.
Let it be clearly understood that all commercial salt is produced
either from the sea or from rock-salt. Sea-water is evaporated to
precipitate its salt either by the heat of the sun or by artificial
heat. Rock-salt is mined and refined for market purposes, and it is
resolved into brine from which the salt is extracted by solar heat or
the process of boiling, but whether the salines are obtained from salt
lakes or from natural brine springs, or are prepared by flooding salt
deposits with water and pumping it out in the form of fully saturated
brine, rock-salt is the foundation for them all. And in all the
processes of manufacture the basic principle is the same, and consists
of applying heat to drive off the liquid which contains the salt and
collecting the crystalline deposit which remains.
The principle of what is described as the boiling process is
fundamental and unalterable, and for thousands of years the plant and
utensils employed in the process underwent no material change. Since
the sixteenth century in England, variations in the shape, size, and
capacity of the pans have been introduced, and experiments have been
made in the re-arrangement of the receptacles and redistribution
of the furnaces, while coal fuel has been substituted for straw and
wood, but it is only in the past twenty-five years that any material
success has been achieved in the matter of economizing and accelerating
the process of production, controlling the heat in order to regulate
the grain of the salt, producing more than one grade of salt in one
operation, or of automatically and continuously collecting the salt as
it is precipitated from the brine.
The earliest exact and detailed description that we have of salt-making
appears in _De Re Metallica_, a famous work by Georgius Agricola, of
Saxony, which was published in 1556, and which for the following 180
years, remained the standard text-book on mining and metallurgy. In
Chapter XII of this work, the preparation of which occupied Agricola
for a quarter of a century, he gives the exhaustive particulars
relating to the boiling process from which the ensuing account is
compiled.
After explaining the method by which sea-water is received into
the first series of prepared trenches, in which the first stage
of evaporation takes place and is thereafter carried into the
second basins, where it is thickened by further evaporation to the
constituency in which it is ready to be converted into salt, Agricola
tells us that the liquor is then boiled in pans placed in sheds
arranged for the purpose. Each shed is divided into three parts. In the
first part is stored the firewood or straw, and in the second is the
fireplace on which is placed the caldron. To the right of the caldron
is a tub for the brine that is to be converted into salt, and on the
left is a bench upon which the salt is placed before being removed to
the third compartment, where it is moulded into cones or tablets and
left to dry in the warm air.
The fireplaces are made 8½ ft. long and 7¾ ft. wide; if wood is burned
in them they are nearly 4 ft. high, but if straw fuel is used, they are
6 ft. in height. The caldrons are rectangular, 8 ft. long and 7 ft.
wide, and 6 in. deep. They are made of sheets of iron or lead, “not
very thick so that the water is heated more quickly by the fire and
is boiled away rapidly.” To prevent the brine from leaking out at the
points where the metal plates are fastened with rivets, the caldrons
are smeared over with a cement of ox-liver, or ox-blood, mixed with
ashes. As soon as the first dipperful of brine is poured from the brine
tub into the caldron, the wood or straw is ignited in the fireplace. If
the firewood consists of faggots or brushwood, the salt will be white,
but if straw is burned the salt is not infrequently blackish from the
sparks which rise with the smoke and settle upon the water.
In order to accelerate the condensation of the brine, the salt-maker
adds and mixes into it bullock’s blood, or calf’s blood, or buck’s
blood, which dissolves and is distributed into all the corners of
the caldron. When the boiling water seems to be mixed with scum, it
is skimmed with a ladle, and from the firing of the furnace to the
skimming of the boiling scum is the work of half an hour. After this it
boils down for another quarter of an hour, and thereafter it begins to
condense into salt. When the brine commences to thicken with the heat,
it is stirred assiduously with a wooden spatula, and then allowed to
boil for an hour. At this stage beer is added to the contents of the
caldron, which is protected from the wind by boards, and the salt is
then withdrawn with a shovel and thrown into baskets. The remaining
brine is allowed to boil for another three-quarters of an hour, when
the salt is again removed and placed in the drying compartment. In
this manner the salters alternately boil the brine and collect the
salt, “day and night, with the exception only of the annual feast
days.” No caldron is able to stand the fire for more than half a year.
New caldrons are washed out three times in the first two weeks, and
afterwards once a week. In this manner the incrustations fall from the
bottom of the caldron, and if this is not done the salt would have to
be made more slowly over a fiercer fire, which not only requires more
brine but burns the plates of the caldron. If any cracks make their
appearance in the caldron, they are filled up with cement. The salt
made during the first two weeks in a new caldron is usually inferior in
quality, being stained by the rust at the bottom where incrustations
have not yet adhered.
Agricola’s description is full of technical exactness in regard to
those parts of the apparatus and the process which are of comparatively
insignificant interest, but it is, unfortunately, silent about details
on which fuller information would be useful. He tells us the capacity
of the tubs in which the brine is conserved, but not of the caldrons
in which it is boiled, and we cannot calculate the quantity by the
dimensions of the receptacles, since he omits to mention the depth
to which they are filled. He explains that it takes half an hour to
fill the baskets with the salt that is drawn from the caldron, but
as he does not give us the dimensions of the baskets employed, or
the amount of wood or straw consumed, we cannot determine the length
of time required to make a certain quantity of salt, or the cost in
fuel. But, condensed and simplified by the elimination of extraneous
particulars and complex technicalities, the foregoing enables us to
obtain a fair idea of the methods employed by the salter of Halle, in
Saxony, assisted by his wife as helper and a youthful stoker--working
naked, on account of the great heat, save for a straw cap and a breech
cloth--in the first half of the sixteenth century.
The subject of the formation of rock-salt deposits will be treated in
a later chapter, in which a description will be given of rock-salt
mining in Cheshire. The primitive methods that characterized the brine
industry have been adhered to with equal tenacity in the winning of
rock-salt. It is extraordinary that, in the manufacture and in the
mining of salt, each successive generation of salt-men, in inheriting
their methods from their forefathers, or adapting them from the miners
of another country, have always preserved the intense conservatism that
appears to be inseparable from the industry, and have resisted all
innovations that have promised to simplify or expedite their labours.
[Illustration: ANCIENT SALT WORKS
_A._ Sheds. _B._ Painted Signs. _C._ First Room. _D._ Second
Room. _E._ Third Room. _F._ Windows. _G._ Window in Roof.
_H_ and _I._ Wells. _K._ Casks. _L._ Pole. _M._ Forked Resting
Sticks
_From an Old Print_ _Published in 1556_·
]
It would be an interminable and unprofitable undertaking to conduct
the reader upon a tour of the salt mines of the world, and explain
the different methods that are adopted to conform with the local
and geological conditions which obtain in the various salt regions.
The systems followed in most countries are governed by traditions
that have their origin in immemorial times, and the disposition to
perpetuate the operations without change through succeeding ages is,
perhaps, traceable to the races that work the mines rather than to
the deposits in which they work. The process of solar evaporation
which is employed to-day on the shores of the Mediterranean and the
Adriatic is practically the same as it was when the civilization of
China was in its infancy; the implements and methods in present use in
the salt mines of Austria, Russia, and Rumania were introduced by the
discoverers of the lodes in the darkest ages. We cannot even fix the
comparatively recent period in which it was decreed that the Rumanian
mines of Tirgu-Ocna and Ocnele-Mari should be exploited by convict
labour, while the Slavic mine was to find employment for free workers
only. Every country, every salt district, and almost every mine has its
peculiar and distinguishing rules, customs, and methods of work, which
are interesting in themselves but of insufficient importance to warrant
detailed consideration in a treatise of this scope. There are, however,
certain salt regions and mines which, by reason of their magnitude and
the possession of unprecedented features, have obtained rank among
the lesser wonders of the world, and for this reason we must devote a
little space to “the Great Salt” of Wieliezka, in Hungary, and to the
great Rumanian salt deposits.
The famous mines of Wieliezka, in the lower Carpathians, about
eight miles from the city of Cracow--with their underground roads,
houses, and monuments; their churches, ball-rooms, and restaurants;
their lakes, bridges, and railway stations--constitute a city
commemorative of the art and industry of bygone periods, and present
a spectacle, weird and splendid, that reminds one of the marvels of
the Thousand-and-One Nights. The Wieliezka system, which has been in
operation since the thirteenth century, extends over an area of about
twelve square miles, and reaches a maximum depth of some 12,000 ft. The
various galleries at present accessible have an aggregate length of 65
miles, and the total length of mining railways is about thirty miles.
Each mine consists of five storeys. The first storey is about 200 ft.
below the surface, and between the different storeys a body of earth
or salt from 80 ft. to 100 ft. thick is left. As in Northwich, many
of the old workings in Wieliezka have fallen in, and whole chambers
and streets have been engulfed in the holes. Broad staircases connect
the various storeys, each of which boasts its distinctive chambers
and thoroughfares. The air in the upper levels is much more moist than
in the lower excavations, with the result that the salt statues in
these apartments are gradually losing their shape. The head of one is
nearly gone, the arms of another are wasted; while the deeper furrows,
which are observable upon the sculptured bodies, give them a grotesque
appearance. The smoke of lamps and wicks adds to the moisture of the
air and darkens the surface of the statues, which might be carved in
black marble. Onward and downward one proceeds, the stairways appear
to be innumerable; the visitor loses all sense of depth, distance, and
direction; chambers and passages lead to further chambers and passages,
until the tour of the workings leaves one with a dominating impression
of limitless repetition. Everything is of solid salt, except where
some insecure roof is supported by huge timbers or a wooden bridge is
thrown over some vast chasm. As depth is attained the air grows drier
and purer, and the points and faces of the rock become more crystalline
and beautiful. Onward and downward still, through labyrinths of shafts,
galleries, and chambers, up crooked passages, and under vaulted
archways, that lead into innumerable, unnamed smaller apartments.
[Illustration: WIELIEZKA SALT MINES, GALICIA. THE BEAUTIFUL FRANCIS
JOSEPH BALL ROOM, MADE OF SALT. THE CHANDELIERS ARE MADE OF POLISHED
SALT CRYSTALS]
Groups and gangs of miners, naked to the hips, are everywhere busy
with pick, mallet, and wedge, with which they block out and separate
the salt slabs from the solid mass. The process has the simplicity
of the age in which it was first employed. The blocks are marked out
on the surface of the rock by grooves. One side is then deepened to
the required thickness, and the face is split off by wedges inserted
under the block. It is then divided into pieces of 100 lb. each and
removed to the shafts, where it is hoisted, stage after stage, to the
surface. The number of labourers continually engaged is from one to
two thousand. The miners, who are muscular, healthy-looking men, are
divided into gangs. The work is carried on in shifts of six hours each,
and in each shift a gang will quarry out about 1,000 lb. weight of salt.
The Letow ball-room, which lies at a depth of 216 ft. below the
surface, dates from 1750, and has been the scene of many Royal visits
and splendid entertainments. One end of the spacious chamber is adorned
with a colossal Austrian eagle, and in an alcove at the opposite end
is set up a crystal throne. The giant chamber which bears the name of
Michalowice, a fearsome and stupendous excavation, was completed in
1701, as the result of forty years of continuous labour. It is 59 ft.
long by 92 ft. broad, and the roof, supported by a wooden framework,
has a height of 118 ft. The chamber is lit by a salt chandelier
furnished with 300 electric bulbs. The Francis Joseph ball-room is
another of the wonders of this subterranean city. It is an immensely
large and immensely lofty apartment, lit by six large chandeliers
fashioned of crystalline rock-salt. Salt statues of Vulcan and
Neptune, which adorn the hall, reflect the electric light from myriad
brilliant points and angles, and contribute to the general impression
of flashing splendour which the scene conveys. Beneath these great
reception rooms, are smaller halls, each beautiful in itself, bearing
the names of royal or princely personages. Massive pyramids of salt and
sculptured monuments, with carved inscriptions, perpetuate the memories
of Emperors and Empresses of Austria, or commemorate their visits to
the mines. Near to the Letow ball-room is the celebrated St. Anthony’s
Chapel, which was hewn in 1698, and for upwards of two centuries has
been the resort of thousands of the devout. The vestibule in the
chapel consists of a symmetrical archway with figures at the sides. The
interior is beautified by an altar bearing a sculptured representation
of the Crucifixion, and flanked by salt effigies of kneeling monks.
Hard by St. Anthony’s Chapel a magnificent shrine is hewn in one of
the passages, peopled with figured saints, which leads to the Queen’s
Chapel, with the superbly-chiselled altar and its view of Bethlehem
carved in the solid salt.
The central railway station in the third storey, and the great
restaurant, with its ponderous pillars and its long vista of latticed
galleries, are among the many marvels of the mines, but nothing it
contains is so wonderful as the subterranean lake, lying 700 ft. below
the surface of the earth. The waters of the lake are dark, thick, and
heavy, and as the boat glides over its surface the slumberous wavelets
roll up against the sides of the grotto with a ghost-like swish. A
ponderous solitude over weighs all. The Styx alone of all the legendary
rivers of death could rival this in stillness. The boat is guided
through the Stephanie and Rudolf grottoes by ropes running on pulleys
along the sides of the curious craft, and the boatman, with his hands
resting on the stern, pushes it with his feet braced against the rope.
Of the sixteen lakes in different parts of the mine, this is the only
one upon which visitors are allowed to go. The report of a gun fired in
the centre of the lake fills the vault with long and lingering echoes,
and the voice of the boatman sounds like a giant’s voice uprising from
the depths of chaos.
The illumination of the mine is arranged according to a regular tariff
based on the number of visitors sharing the expense. For any number
of persons up to twenty, the illumination, which comprehends the
employment of over a thousand candles and electric lamps, costs about
ninety shillings, but for an additional sovereign, which is charged
when a party numbers over thirty persons, the whole mine becomes a
blaze of light.
[Illustration: INTERIOR OF SALT MINE AT SLANICU, RUMANIA
This famous mine has been worked since the time of the Romans.]
Serious calamities at Wieliczka are now practically unknown, owing
to the care exercised by the officials, but minor accidents are
unavoidable. Some few years ago a huge mass of rock-salt, weighing
some 200 tons, fell from the roof of one of the chambers; in 1868 the
mines were flooded by the bursting of a subterranean salt lake; and a
fire in 1815 resulted in the loss of several hundred lives. The early
history of the mines contains the record of several terrible disasters,
including an incendiary fire in 1510, which caused a great number of
deaths, and another fire in 1644, which raged for over a year, and
consumed all the people, horses, and mules who were in the mine when
the fire occurred.
The working of the three great Rumanian salt deposits present other
examples of the persistent survival of ancient methods, but it must
be admitted that an attempt was made at one time to introduce modern
machinery. It was demonstrated that the machine produced more salt in
a given time, and that the waste of about 25 per cent. of the salt
attendant upon manual labour and the use of picks was saved, but as
the supply of salt is practically inexhaustible, and there is no
limit set upon the time of winning it, and as man-power, especially
convict man-power, is cheaper than machinery, the authorities soon
reverted to the old system. In the Slanic mine, in which the salt is
crystalline, white, and almost absolutely pure, the free labourers, of
whom about 500 are employed, are divided into gangs of six men. Each
man takes an oblong piece of the floor of the mine, about as big as
an ordinary tombstone, and, using his pick, scoops round it a narrow
groove about 5 in. deep. This done, he summons the rest of his gang,
and, standing beside him on the slab, they raise and bring down their
picks simultaneously at the word of command. Force is necessary, but
rhythmical accuracy in the planting of the blow is more essential, and
by long practice the men have become so extraordinarily expert that
they scarcely ever diverge a hair’s breadth from the point at which
they aim. In a few minutes the persistent blows detach the slab, which
the six men raise with the aid of a lever. The gang proceed from slab
to slab until all six have been detached and lifted, after which each
man breaks his own slab into chunks and loads it into a truck for
removal to the shaft, through which it is hauled to the surface. An
expert miner’s earnings at this work range from half a crown to three
shillings a day.
The convicts employed in the Tirgu-Ocna and Ocnele-Mari mines are
paid from sixpence to eightpence a day for their work, and, save that
liberty and the hospitality of the local taverns are denied them,
their condition is little worse than that of the free labourers. As
capital punishment does not obtain in Rumania, the convict miners
include murderers, brigands, and the worst class of criminals, and
armed soldiers escort them to and fro between the prison and the mine,
and remain on guard while they are at work. Dashes for liberty used to
be common, and organized attempts to escape have also been attempted,
but now, on the first sign of suspicious behaviour on the part of the
convicts, the order is given for the whole gang to throw themselves
flat upon the ground. As those who disobey the order are immediately
shot, instantaneous compliance with the command is usually observed. On
one occasion a body of disaffected convicts had recourse to a form of
passive resistance, and when the day’s work was over they refused to
leave the mine. The guards and overseers thereupon withdrew and left
the mutineers to reflect in an intolerably salt atmosphere upon the
virtues of fresh water, of which they had no supply. After two days
of torture, the men capitulated. But the work of superintending the
convicts in the mines is a delicate and dangerous task. The overseers
are compelled to mix with the men, and it is but the work of a few
silent minutes for a gang to overpower an unpopular official and
squeeze the breath out of his body. As the murder is a communal affair,
and the practice of making an example of one man _pour l’encourager les
autres_ is not adopted in Rumania, the extent of punishment inflicted
upon the whole gang is less than would be meted out to individual
offenders. As the salt reserves in the three principal mines of Rumania
are estimated at 8,774,000,000 tons, and the annual extraction has
never exceeded 150,000 tons, it follows that, at the present rate of
progress, the deposits cannot be exhausted for several millenniums.
Where the salt deposits are composed of a mineral that is white,
odourless, and practically pure, as in the Wieliezka system and the
mines of Rumania, and particularly if labour is abundant and cheap, and
the industry is a monopoly of the State, rock-salt mining will always
hold its own.
[Illustration: WIELIEZKA SALT MINES, GALICIA. THE RAILWAY STATION ON
THE THIRD LEVEL]
Even in this country, when the old open-pan system of evaporating
salt from brine produced only two tons of salt for the consumption of
a ton of fuel, rock-salt could be raised, purified, and marketed in
competition with white salt, but the modern boiling processes have
effected such substantial improvements and consequent economical
advantages, that the rock-salt industry appears to be doomed to
decay. Rock-salt, as quarried from its native bed, is found in many
variations of colour, from grey and yellow to green and brick red,
according to the nature of the impurities of the locality in which
the deposit lies, and such salt must be cleansed from all traces of
iron, clay, gypsum, or bitumen before it is fit for domestic use. Many
processes have been experimented with for the removal of impurities.
One of the most plausible methods was based on the fact that salt fuses
at a temperature of about 1,750 degrees, and the theory was to remove
all impurities from the fluid mass by the agency of compressed air. The
principle was unsuccessfully experimented with in Würtemberg nearly
half a century ago, but a modern adaptation of the process claimed
to be more successful. The molten material, in this case, ran into
rotating pans and gradually overflowed; and it was then shovelled into
another receptacle and, while subjected to the action of compressed
air, raised by small buckets to a certain height and emptied into
inclined screens, through which it was automatically graded. It was
claimed that from the time of casting the crude material into the
furnace, until the perfect white salt appeared, the process occupied
only fifteen minutes, and that rock-salt could be broken in the mine,
transported, fused, and packed ready for table use in less than two
hours.
At the time when the master-patent for this process was taken out, the
latest brine-evaporating systems were unperfected, and there was some
possibility that the invention might be capable of taking the rock-salt
direct from the mine, eliminating at one stroke all its impurities,
and in the course of an hour or two delivering into the warehouse an
anhydrous salt “at a fraction of the cost of the ordinary process”
of evaporating salt from brine. But by the time that this bold claim
was put forward on behalf of the process, the admitted total cost of
production had been advanced from 4s. to 5s. 8d. per ton, while the
latest patent brine-evaporating system was producing the manufactured
article at a total inclusive cost of 3s. 6d. per ton. Since then, this
rock process was installed in Mexico, persevered with for a while, and
finally discarded because, in the words of Mr. W. L. Bonney, the United
States Consul, “the experiment proved a failure.” Even if the latest
brine process has not “relegated rock-salt mining into the limbo of
extinct enterprises,” it appears certain that it will never be able to
be worked in competition with the process by which salt is manufactured
direct from brine where brine is available.
CHAPTER III
THE CHESHIRE WICHES
If we turn from the study of salt as one of the staples of world
industry to the history of the salt industry in England, we find
that it is practically comprised in the records of the development
of the trade in rock-salt and brine in the county of Cheshire. The
first documentary reference to the existence of saline deposits
in this country, as well as the earliest mention of the method of
native manufacture and of the introduction of the open-pan system of
salt-making, dates from the time of the Roman occupation. The Caesarean
soldiers, who penetrated as far north as the Northwich district, found
the people obtaining salt by the process of pouring brine upon faggots
of charcoal and scraping away the resultant crystalline formation. A
little spring which existed at that period in Sheath Street, Northwich,
furnished the Romans with a limited supply of brine, and from this
source, with the crude plant improvised on the spot, they produced the
first salt ever manufactured in England by the boiling of brine in open
pans.
The Britons named the brine spring at Nantwich “Hellath Wen,” or the
White Pit, on account of the whiteness of the salt produced from its
waters; while the spring at Northwich received the name of “Hellath
Du,” or the Black Pit. The suffix “wich” may have been introduced into
Cheshire direct from the Vikings of the North, or brought there by
way of the south-eastern counties. In Camden’s _Britannia_ (published
in Latin in 1607, and translated by Philemon Holland, 1610), we read
that the word Wiccij “may seeme to have beene derived of those _salt
pittes_ that the old Englishmen in their language named _Wiches_,”
and William Smith, a Cheshire Man and author of a work which is known
as King’s _Vale Royal_ (1656 edition), says: “The house in which the
salt is boiled is called the Wychhouse; whence may be guessed what
_wych_ signifies, and why all those towns where there are salt-springs
or salt made are called by the name of _wych_, viz., _Namptwych_,
_Northwych_, _Middlewych_, _Droitwych_.” But the Norse word _wig_ and
the Anglo-Saxon _wic_ signified, in the original, a dwelling-place,
and in the latter form of _wich_, it is seen in the names of Woolwich,
Norwich, Harwich, Sandwich, etc. The Norse and Danish pirates
who visited our coasts to pillage and procure salt, established
_wigs_--afterwards wiches or hamlets--on the bays and inlets, and
wherever they located themselves they proceeded to make bay-salt. The
word _wich_, in course of time, became identified not with the village
but with the salt manufacture that was carried on there, and when the
Cheshire towns developed the industry they may easily have adopted the
nomenclature that was already regarded as indicative of the manufacture.
In the records of Droitwich, which was also called Durt-wich “by reason
of the wettish ground on which it stands,” we learn that in the year
816, Kenulph, King of the Mercians, gave Hamilton and ten houses in
Wich together with their salt-furnaces, to the church of Worcester,
and that in 906 the same church was endowed by Edwy, King of England,
with Fepstone and five salt-furnaces; but the next earliest references
to the Cheshire Wiches must be searched for among the entries in
Domesday Book, which was prepared between 1084 and 1086. William the
Conqueror’s authorized inquiry as to the several places in which salt
was being made, and the persons who had held proprietorial rights in
them since the time of Edward the Confessor, was productive of much
detailed information. From the zincograph reproduction of the original
made by Mr. William Beaumont in 1863, it would appear that the Cheshire
brine-springs and salt works were strictly held, and were subject to
certain well-defined customs. In several localities the existence of
solitary salt-houses is mentioned, and it would seem safe to infer
that the supply of brine was obtained in the vicinity and the salt was
only made for local consumption. Salt-making for commercial purposes
was confined to Nantwich, in Warmundestron Hundred, and Northwich and
Middlewich in the Hundred of Mildestvic, and, although no figures
relating to output or revenues are given, the laws governing the trade,
the prices charged, and the method of dividing the moneys accruing from
rents and sales are concisely set forth in the following paragraphs--
“Mildestvic hundred. Hugh and William held of the Earl Rode Godric and
Ravesa held it for two manors and were free men.”
“In the same hundred of Mildestvic there was a third Wich called
Norwich (Northwich), which was in farm at eight pounds. In it there
were the same laws and customs as in the other Wiches, and the King
and the Earl divided the receipts in the like manner. All the thanes
who held salt-houses in this Wich gave no Friday’s boilings of salt
the year through. Whoever brought a cart, with two or more oxen, from
another shire, gave 4 pence for the toll. A man from the same shire
gave for his cart 2 pence within the third night after his return home.
If he allowed the third night to pass, he was fined 40 shillings. A man
from another shire paid 1 penny for a horse load. But a man from the
same shire paid 1 styca within the third night after his return, as
aforesaid. A man living in the same hundred, if he carted salt about
through the same county to sell, gave a penny for every cart, for as
many times as he loaded it. If he carried salt on a horse to sell,
he gave 1 penny at Martinmas. Whoso did not pay it at that time was
fined 40 shillings. All the other customs in the Wiches are the same.
This manor was waste when Earl Hugh received it. It is now worth 35
shillings.”
“_Nantwich._--In King Edward’s time there was a Wich in Warmundestron
hundred, in which there was a well for making salt, and between the
King and Earl Edwin there were 8 salt-houses, so divided that of all
their issues and rents the King had two parts and the Earl the third.
But besides these, the Earl had one salt-house adjoining his manor of
Acatone (Acton) which was his own. From this salt-house the Earl had
sufficient salt for his house throughout the year. But if he sold any
from thence, the King had twopence, and the Earl a third penny, for the
toll. In the same Wich many men from the country had salt-houses, of
which this was the custom--
“From our Lord’s Ascension to Martinmas, anyone having a salt-house
might carry home salt for his own house. But if he sold any of it
either there, or elsewhere in the county of Chester, he paid toll
to the King and the Earl. Whoever after Martinmas carried away salt
from any salt-house except the Earl’s, under his custom aforesaid,
paid toll, whether the salt was his own or purchased. These aforesaid
8 salt-houses of the King and the Earl, in every week that salt was
boiled or they were used on a Friday, rendered 16 boilings of salt, of
which 15 made a horse-load. From our Lord’s Ascension to Martinmas,
the salt-houses of the other men did not give these Friday’s boilings.
But from Martinmas to our Lord’s Ascension, these boilings were given
according to custom, as from the salt-houses of the King and the
Earl. All these salt-houses, both of the lord and other people, were
surrounded on one part by a certain river, and on the other part by
a ditch. Whosoever committed a forfeiture within these bounds, might
make amends, either by the payment of 2 shillings, or by 30 boilings
of salt, except in the case of homicide, or of a theft, for which the
thief was adjudged to die. These last, if done here, were dealt with
as in the rest of the shire. If out of the prescribed circuit of the
salt-houses, any person within the county withheld the toll, and was
convicted thereof, he brought it back and was fined 40 shillings, if
a free man; or if not free, 4 shillings. But if he carried the toll
into another shire, where it was demanded the fine was the same. In
King Edward’s time, this Wich, with all pleas in the same hundred,
rendered 21 pounds in farm. When Earl Hugh received it, except only one
salt-house, it was waste. William Maldebeng now holds of the Earl the
same Wich, with all the customs thereto belonging, and all the same
hundred, which is rated at 40 shillings, of which 30 shillings are put
on the land of the said William, and 10 shillings on the land of the
Bishop, and the lands of Richard and Gilbert which they have in the
same hundred, and the Wich is let to farm at 10 pounds.”
“_Middlewich._--In Mildestvich hundred there is another Wich between
the King and the Earl. There, however, the salt-houses were not the
lord’s, but they had the same laws and customs that have been mentioned
in the above-mentioned Wich, and the customs were divided between the
King and the Earl in the same manner. This Wich was let to farm for 8
pounds and the hundred wherein it was, for 40 shillings. The King had
two parts, and the Earl the third. When Earl Hugh received it, it was
waste. The Earl now holds it, and it is let to farm for 25 shillings,
and two wain-loads of salt. But the hundred is worth 40 shillings. From
these two Wiches, whoever carried away bought salt in a wain drawn by
four oxen or more, paid 4d. for the toll; but if by two oxen, 2 pence
if the salt were two horse-loads. A man from another hundred gave 2d.
for a horse-load. But a man of the same hundred gave only a halfpenny
for a horse-load. Whoever loaded his wain so that the axle broke within
a league of either Wich, gave 2 shillings to the King’s or the Earl’s
officers, if he were overtaken within the league. In like manner,
he who loaded his horse, so as to break its back, gave 2 shillings
if overtaken within the league, but nothing if overtaken beyond it.
Whoever made two horse-loads of salt out of one, was fined 40 shillings
if the officers overtook him. If he was not found, nothing was to be
exacted from any other. Men on foot from another hundred buying salt,
paid 2d. for eight men’s loads. Men of the same hundred paid 1d. for
the same number of such loads.”
The first private record relating to salt appears in the foundation
deed of Combermere Abbey, dated 1132, in which Hugh Malbane, the
founder, caused it to be written: “And I also grant to the same monks
the fourth part of the town of Wych, and tythe of my salt and of the
salt pits that are mine, and salt of Blessed Mary the Virgin, and salt
on Friday, and salt for the Abbot’s table as freely as I have it at my
table.”
Ancient Deeds in the Record Office contain occasional reference to salt
properties in the thirteenth and fifteenth centuries which show that
salt was made in limited quantities in Cambridgeshire and at Rye,
Mimera, and Brembre (formerly Hayerskys), in the County of Sussex.
Protests against the importation of salt from abroad, and of
salt-making by foreigners contrary to the liberties and ancient
customs of the borough of Northwich, are recorded in the Harleian
MSS. In response to a complaint made on behalf of the burgesses and
inhabitants of Northwich concerning the mischievous irregularities
committed in the making of salt by “p’sons forrayne and not inhabiting
w/thin the Sḍ towne,” King Henry VIII issued an Order to the Justice
and Chamberlaine of the County Palatine of Chester to the effect:
“_WHEREFORE_ we will and command you that in any case such forrayne
p’son or p’sons not inhabiting within the s/^d towne, do, or hereafter
at any time shall attempt to use makeing of salt contrary to the
lib/^{er}ties and ancient customes of the same within the same towne
without lycence of the burgess and the rulers thereof. _THAT_ then
without delay ye and ether of you from tyme to tyme upon complaynt
or of the rulers and govnors of the same towne do send for all and
every such forrayne p’sons as do or hereafter shall attempt to make
any salt within the s/^d towne of Northwich contrary to the libties
and ancient customes of the same, without the assent and agreem/^t of
the s/^d Burgess and ruler by o/^r writts of subp: to appear before
you in o/ Castle of Chester at there appearance to punish and reforme
them: And also further to order them as right and good conscience shall
require according to the lawes and customes heretobefore used now in
other wyches there abts w/^{th}in o/^r s/^d County Palatyne, for the
reformacon of such transgressions fayle ye not hereof as ye maye intend
to please us.”
In the time of the Tudors, the salt-makers of Cheshire were composed
of natives and “forrayners,” or residents born outside the boundaries
of the county, and in the Northwich Book of Orders is given a list
of ten “outliers” in the town of Northwich who occupied between them
no fewer than eighty-nine salt pans or leads. Although we have no
information as to the exact size and capacity of the evaporating pans
of the period, it is evident that they were made to a regulation scale,
and we read that it was the business of an officer of the Court Leet
to examine the leads and see that they conformed with the standard
dimensions. If the prescribed measurements were exceeded, the official
cut a piece out of the corner of the pan with a pair of shears with
which he was furnished for the purpose, so as to reduce its capacity to
the legal limit.
Only three of these old salt-pans have been recovered, and, of these,
one was cut up and sold as old lead. One which was drawn out of the
river at Northwich in 1866 was forwarded by the River Weaver Trustees
to the Warrington Exhibition, and was transferred subsequently to the
Northwich Museum. This pan measures 3 ft. 8 in. long on one side, and
3 ft. 4½ in. on the other; it has a width of 2 ft. 8 in., and is 4 in.
deep. The thickness of the lead is about half an inch. and the weight
of the pan is 2 cwt., 1 qr. 18 lb. There are raised patterns on each
end of the pan, which was evidently cast, and the sides are rounded up
from the bottom. In 1878, in the vicinity of Ashton’s Salt Works at
Witton, was found a smaller pan made out of a sheet of lead 2 ft. 8
in. square. The sheet was bent up to form a pan and the corners were
hammered together. This lead is 25 in. square by 3 in. in depth, and
has a capacity of about 7 gallons.
In the early years of the reign of James I we have particulars of the
salt districts in Camden’s _Britannia_, and in a letter received in
February, 1605, from Chomley written by one George Johnson. Camden
explains that the Cheshire _Wiches_ were so-called because “there
bee here very notable _salt pits_ and many salt springs often-time
have been found which notwithstanding are stopped up, because it was
provided (as wee read) that for the saving of woods, salt should not be
boiled but in certain places.”
[Illustration: SUBSIDENCE NEAR THE DANE BRIDGE, NORTHWICH]
Meagre as these accounts are in exact particulars, they constitute the
only information we have concerning the supply and treatment of brine
in England in the early days of the industry, and, consequently, they
invite attention. Camden is responsible for the following details--
“At _Northwich_ there is a deep and plentiful brine pit with stairs
about it, by which, when they have drawn the water in their leathern
buckets, they ascend, half naked, to their troughs and fill them, from
whence it is conveyed to the wich-houses about which there stand on
every side many stakes and piles of wood.
“_Nantwich._--There is but one salt pit here (they call it the brine
pit) distant about 14 ft. from the river. From this brine pit they
convey water by wooden troughs into the houses adjoining, where there
stand ready little barrels, fixed in the ground, which they fill with
that water; and at the notice of a bell, they presently make a fire
under their leads, whereof they have six in every house for boiling the
water. These are attended by ‘Wallers’--a name probably derived from
the Anglo-Saxon _weallere_, a boiler; German, _wallen_, to boil--who
with little wooden rakes, draw the salt out of the bottom of them and
put it in baskets, out of which the liquor runs, but the salt remains
and settles....
“The depth of the salt springs is in some places not above three or
four yards. In Nantwich the pit is full 7 yards (deep) from the
footing about the pit: which is guessed to be the natural height of
the ground, though the bank be 6 foot higher, accidentally raised by
rubbish of long making salt or “walling,” as they call it. In two
places within our Township, the spring breaks up so in the meadows as
to fret away not only the grass, but part of the earth, which lies
like a breach at least half a foot or more lower than the turf of the
meadow: and hath a salt liquid ousing (oozing) as it were out of the
meed but very gently.
“_Droitwich_ possesses three fountaines yielding plenty of water to
make salt of, divided asunder by a little brooke of fresh water passing
betweene, by a peculiar gift of nature spring out: out of which most
pure white salt is boiled for six months every yeare, to wit, from
Midsommer to Midwinter, in many set fornaces round about: wherewith a
mighty deal of wood is consumed, _Fakenham Forest_ (where trees grew
sometime thicker), and the woods round about, if men hold their peace,
will by their thinness, make manifest more and more....”
Of the two wells of salt-water at _Middlewich_, which are separated
by a small brook, we are only told that “one stands not open but at
certain set times, because folke willingly steale the watere thereof,
as being of great vertue and efficacie.”
More informative on essential points is the unknown correspondent of
George Johnson, who writes as follows--
“_Namptwich._
“There is in the town of Namptwich two hundred and sixteen
salt-houses of six leads apeece, and every of the said houses
doth spend in wood per annum eight pounds so as there is spent
in wood yearly within the said town in omnibus annis.... £1728
“_Middlewich._
“There is, in the said town, one hundred and seven salt houses
of six leads apeece, and one of four leads and every of the
said houses doth spend yearly in wood the sum of £13. 6. 8, so
as there is spent every year within the said town, £1435. 4. 0.
“_Northwich._
“The said Northwich is a Burrow and holden of the Earle of
Chester by the service of twelve armed men to serve at the
Watergate in Chester in the time of wars betwixt England and
Wales. There is, in the same towne or Burrow, one hundred and
thirteen salt houses, every one containing four leads apeece,
and one odd lead and one four leads which was given to the Earl
of Derby by the Burgesses, occupiers of the said Town, for the
portion of his house, and no land in the Town for it, and every
four leads must have in provision of wood, nine quarters and so
rateable, whether it be four leads or six leads, so that there
is spent in wood in the said town 1026 quarters and a peece
after the rate of five score to the hundred and after the rate
of forty shillings per Quarter comes to £2056. 10. Spent in the
wich houses yearly in wood, £5219. 14.”
The particulars which are given of the salt manufacture in the Wiches
in 1605 and 1607 by George Johnson’s correspondent and by Camden, are
repeated with only the slightest variation half a century later in
King’s _Vale Royal_. But in the latter account we are able to glean
a little more information about the towns themselves. Concerning
Northwich, we are told that it had the mischance to be burnt in July,
Anno 1438, and was “most part miserably consumed with fire,” in
December, 1583. “But through the Benevolence gathered throughout the
Realm, it is new builded, and is in as good case or rather better than
before.” The town in 1656 was divided into two parts, one of which
was called the Cross, while a “very fair church of stone,” called
Northwich Church, stood “without the Town’s-end.” But although it was
called Northwich Church, we are told that it was only a chapel and its
proper name was Witton; a combination of coincidences which caused
the chronicler to conclude “that the town was named first Northwich,
after the finding of the salt.” Of Nantwich, we are only informed that
the town was visited in 1617 by the gracious King’s Most Excellent
Majestie, who, with his own eyes beheld the manner of the brine well
and the labours of the drawers of brine--who, in the course of their
work, “spend the coldest day in frost and snow, without any clothing
more than a shirt with great cheerfulnesse”--and “with his own hand
most princely rewarded them.” Middlewich is described by the same
authority as no market town: “yet may it pass amongst them, as well for
the bigness thereof, as also it hath Burgesses and other privileges,
as the other wiches have, yet it hath a small market of flesh and
other things every Saturday, and yearly two fairs: that is to say on
Ascension Day and St. Luke’s Day. It hath divers streets and lanes,
as King Street, Kinderton Street, Wich House Street, Lewis Street,
Wheelock Street: Pepper Lane: Cow Lane and Dog Lane. But the chiefest
place of all is a broad place in the middest of the Town, in manner of
a market place, called the King’s Mexon.”
A large accumulation of matter of great local and antiquarian interest
is to be found in the Northwich Book of Orders, the Court Rolls, and
the Walling Booke of Northwich, which consist of documents and records
relating to the government of the town and the regulation of its salt
industry about the middle of the seventeenth century. The “Ancient
Customes of the Burrow and Town of Northwich,” the inventory of “The
Liberties and Priviledges of Burgesses,” and the Orders “concerning the
making of salt,” were collected and set down by Peter Warburton, of
Chester, Esquire, Steward of Northwich, and afterwards a Justice of the
Court of Common Pleas at Westminster. At a Court held on 18th December,
1608, this compilation, “so full of interest and instruction,” was
ratified and confirmed by Thomas Berrington, Gentleman, Steward of the
said Court, and a jury of Burgesses, and Thomas Poole, Gentleman, Clerk
of the said Court, was instructed to write them into a Booke “to the
end the same may remain upon record to future ages.”
The Nine Customes, numbered 10 to 18, which were written in 1638,
were supplemented in 1641 by other Nine Customes, numbered 1 to 9,
which had been “heretofore omitted merely through forgetfulness.” Of
the eighty-four Orders relating to salt-making which appear in these
records, the first sixty-one were agreed upon by “The Steward and
Jury at Diverse Courts” up to 1629, the seven following were added in
1630, and seven more appeared on the rolls before Master Poole made a
fair copy of the Orders in 1638. In the following year eight further
regulations were issued. Order No. 84 bears the date of December, 1656,
and only three subsequent unnumbered enactments were included up to
1666, when the record comes to an end.
Although these old Orders (1629–1666) include directions relating to
the general behaviour of the townspeople, injunctions concerning the
sales of liquor and butchers’ meat, the malpractices of begging at
men’s doors, piking or stealing wood, “scoulding or chideing ... to
the trouble or disquietness of the good and honest neighbours,” and
rules for the maintenance of cleanliness in the streets and public
places and the publication and preservation of Proclamations put forth
by the King, the bulk of the laws are framed in the interests of the
staple industry of the district. No detail connected with salt-making,
from the drawing of the brine to the transport of the manufactured
product, is left to chance or the discretion of the individual. The
rights and privileges of Burgesses, and particularly of such as occupy
salt-houses or wallings, are set forth in the Ancient Customes, but
in all particulars relating to the making of salt, the Orders are
paramount and precise. Space does not permit of the reproduction here
of the whole of the regulations, but a few of the Items may be quoted
as evidence of the care and thoroughness with which they were framed.
“7. Item. It is ordered that no man shall enter into the Lead-looker’s
book any more walling or occupation for one Wich-house than six leads
walling upon paine for every offence ... 10s.”
“15. Item. That if any Person or Persons receive into their Houses
any Wood by Night or by day by the way of Exchange for Candles, Meat
or Drink every such Person as well the Changer as the Receiver shall
pay fine to the Lord for every default 5s. or to be punished by the
Steward.”
“17. Item. That every Waller shall sell the salt she maketh by the
Walme or Cranock and not by the sack or load, and at the price which
the officers sett down to be the com’on price of the Towne upon pains
for every default 3s. and also to make up the full price to her Mr.
upon her wages.”
“18. Item. That no Waller nor no other Person shall make any fire in
the Wich-house streets in the night time, and every such offence to
be presented by the Bailiffe at any single Court and punished by the
Steward according to his discretion.”
“22. Item. That no person shall deliver any bryne to be carryed out
of this Towne either in Hodge heads or Barrels (except upon Woemen’s
heads) upon paine to forfeit to the Lord for every such offence ...
20s.”
“24. Item. That there should be left at every pile made at the end of
any Wich-house or Wood roome a yard and a halfe between the said pile
and the Crest of the Pavement to the intent that waynes may have better
passage upon paine of 6s. 8d. presentable at any single Court.”
“26. Item. It is ordered that no Person from henceforth shall be
suffered to wall or occupy any Odd Lead as 3, 5 or 7, but 2, 4 or 6
Leads for avoiding of trouble to the officers except in such case as
cannot be remedied upon paine of ... 10s.”
“27. Item. It is ordered that henceforth no Person shall occupie
Walling unless they first continue a householder for the space of three
years and after such time expired to be allowed by the Steward or his
Deputy, and the Lead-lookers (except he be a Burgess) upon paine to
forfeit for every lead ... 13s. 4d.”
“33. Item. That all Inhabitants and Occupiers of the Towne do aide and
assist lawfully every Officer of the Towne in Executing their office
lawfully upon paine every one that offendeth to pay for every offence
... 10s.”
“40. Item. It is ordered that if any Waller be found making of Course
Salt when they might make it better if they would, the Lead-lookers or
Salt-viewers so finding them and making presentment thereof e’ry such
Waller so offending shall fine to yr Lord for e’ry offence therein ...
2d.”
“43. Item. We do also order that every Occupiers’ Leads of this town
shall henceforth be made Tenn stone weight a peece to the pan before
they be cast, upon paine of the Lead-casters forfeiture to the Lord of
this Towne for every default in casting any Leads contrary to this
order the sum of ... 10s.”
“63. Item. It is also ordered that every occupier of Walling or his
Waller, or his Serv^{ts} shall weekly make cleane ye pavem^t ag^t their
Wich-Houses one yard and a half from the middle of the pavement upon
paine to forfeit for every such offence ... 12d.”
Duly set forth in these records are the forms of oaths to be
administered by the Court to those who “shall well and truly execute
the office” of Constable, Lead-looker, Overseer, Salt-viewer, Assessor,
Killer of Salt, Market Looker, Sealer and Searcher of Leather,
Ale-Taster; Skavinger, Gutter Viewer, Wood Tender, or Pan Cutter. Each
of these important officers in the prescribed form must “swear by the
holy Contents of this Booke,” to “spare no man for any love, favour or
affection” in the fulfilment of his several duties but “of all Defaults
and Defects that you find in the execution of yo^r office you shall
present at every Single Court to be holden after such Default made--So
help you God.”
The compiler of _Vale Royal_ (1656) does not admit that he is indebted
to the Northwich Book of Orders for his information, but he alludes in
general terms to the “authentique rules and customes” which regulate
the manner of making salt in the Cheshire wiches, and adds: “All these
things I leave to be read other where, knowing well their jealous love
to be such towards this their beloved commodity as I should soon incur
some reprehension for being too busie to look narrowly upon such a
beauty.”
[Illustration: DUNKIRK SUBSIDENCE, NEAR NORTHWICH]
In “A Copie of The Walling booke of Northw^{ch},” amongst the Harleian
MSS., the earliest list of occupiers of wich-houses with the number of
leads, together with the names of such persons as had wich-houses of
Inheritance in the town, with their number of leads, was compiled in
1565, and gives a total of “five score and thirteene Salt houses and
one lead.” A list of owners and of salt-houses arranged in the form of
a street directory was drawn up in 1593, and, about 1600, a revised
list, compiled in accordance with the location of the houses, and
giving the number of leads in each, was supplemented by a street plan
of the town. In the list of 1589 it is recorded that--
“Our Soveraigne lady the queene hath two salt-houses of free
occupa’ion, and toulfree wth all and one is Judger of Cogshall.”
In the list of 1604, the King appears as the owner of two salt-houses,
and it is assumable that His Majesty acquired an additional half
of a salt-house in the following year, since, in the more detailed
compilation drawn up in 1605, we read that--
“Our Soveraigne Lord the Kings Maj^{ty} hath two Salt-house and
a halfe which be both towle free and ffine free and is Judger
of Cockshall.”
The King’s name as the owner of “2½ towle free and fine free”
salt-houses heads the list for 1619 and that for 1636–1638. This last
contains the names of forty-six lords and owners of salt-houses, having
an aggregate of over 400 leads.
It was the custom to repeat the legend either at the beginning or the
end of each succeeding list that--
“There is and tyme out of mynd hath been within the Towne of
Northwich 112 four leads and one odde lead and noe more; and
four leads called the Running Wich-house. Soe the totall is 113
four leads and one odde lead.”
This formula was evidently only a fable. The discrepancy between the
figures and the statement was pointed out by a scribe in 1630, who,
having cast up the number of leads tabulated in the list of 1589,
appended the following note: “These leads answere but unto 308 leads
whereas there is 453 leads yearly walled for ut pateat ante: soe that
there wanted 145 leads to make up the full accoumpt for 308 leads and
145 leads make but just 453.”
There are about 450 leads accounted for in the next list, which was
drawn up in 1593, but the clerk persisted in the assumption that what
had been “time out of mynd” could suffer no change, and he formally
declared, despite his own figures to the contrary, that “the totall
some is 113 four leads and one odde lead, which stand in the Towne rowe
as is before written and declared.”
On folio 61 of one of the Harleian MSS., following the list of
Northwich salt-owners for the years 1636–38, are undated lists
of salt-owners of Middlewich and Nantwich. The clerk admits the
incompleteness of the list of twenty-two owners in Middlewich, but he
explains that the names he gives are “as manie as I can learne for the
p’sent,” and he adds, “But the number of their sev’all and respective
howses and leads I cannot learne.” Only five owners appear in the
returns for Nantwich, and the meagre particulars that the clerk has
been able to acquire respecting the other salt districts of Cheshire
are contained in the following note: “There is another Wiche where
there is a great store of Salt made in Cheshire And w^{ch} is of greate
Antiquitie called Fulwich, also Durtwich, and my Lo: Brereton is an
owner of sev’all wich-houses theire. But whoe are owners of the rest I
cannot learne.”
Nantwich was long famous among the Wiches for its production of the
finest and best white salt. The Welsh named it Hellath Wen, and
the _London Magazine_, in 1750, translated the words as the “White
Salt Town,” but there is no reference to the quality or colour of
its output in the present name, which is derived from the Welsh
word “nant,” a vale, and the Saxon “wyche.” That its salt was good,
plentiful, and of considerable commercial value would seem to be shown
by the fact that under the Saxons the supplies were in the hands of the
princes and nobles, and William the Conqueror had not been in England
more than a year before he divided the salt production of Nantwich
between himself and Earl Edwin, who owned some salt-houses in the
district.
According to Leland, there were 400 salt works at Nantwich in the reign
of Henry VIII, but the number was reduced to 216 under Elizabeth, and
in 1624 only 108 were in existence. Nantwich was described in the
_London Magazine_ of 1750 as the largest and most considerable town in
the county next to Chester, but its salt industry at that period was
fast declining. An Act of Parliament which had been obtained in 1734 to
extend the navigation of the river Weaver from Winsford to Nantwich,
was never put into operation. In 1778 the salt works had been reduced
to two, each containing five large pans of wrought iron. The Nantwich
salt industry was practically moribund in 1849, but some twenty-five
tons per week were produced by one maker until 1856, which is the
last year in which salt was made in the district. In 1891 a company
was registered for the purpose of acquiring property in Nantwich and
manufacturing salt from brine, but the necessary financial support
was not forthcoming and the project was abandoned. The decline of the
Nantwich salt industry is ascribed in Poole’s _History of Cheshire_
(1778) to various causes, including the frequent destruction by fire
of the works in the town--“fourteen of which in the memory of persons
living lately, having been destroyed in one day”; to the discovery and
exploitation of new salt springs in adjacent localities; and to the
superior advantages in the matter of accessibility which were possessed
by Northwich and Winsford.
Northwich, described by the Welsh as Hellath-du, became the chief of
the Cheshire salt towns in the seventeenth century, and its output
of brine is still greater than that of any other district. In 1605,
Northwich had 449 leads, against 642 leads at Middlewich and 1,296
leads at Nantwich, but the comparative superiority of the brine pumped
at Nantwich over that of her rivals is demonstrated by the relative
amount of boiling required to precipitate the salt. In Northwich, the
annual expenditure for wood fuel was £2,056; Middlewich, with nearly
one-third more leads, consumed wood fuel to the amount of £1,435
yearly; while Nantwich, working twice as many leads as Middlewich, and
nearly three times the number operated at Northwich, had an annual wood
bill of only £1,728.
In 1670, Winsford, which had only just started as a salt producer,
had two salt works in operation on a small scale. In 1675, Lord
Brereton ignored the output of Winsford in his calculation of the
total annual salt production of the Cheshire works at 26,927 tons.
In 1878, or practically two centuries later, the Cheshire output of
salt was calculated at 2,055,000 tons, made up as follows: Winsford
and District, 1,036,000 tons; Northwich and District, 880,000 tons;
Middlewich and District, 21,000 tons; and the newly-developed Sandbach
District, 118,000 tons. But while Winsford has surpassed her older
competitors in the matter of salt production, Northwich is still the
commercial centre of the industry and the greatest producer of brine;
whereas, in the case of the other districts, the brine is converted
into salt on the spot, the Northwich brine, to the amount of hundreds
of millions of gallons annually, is pumped out of the neighbourhood
through the Marbury pipe, to be employed in the chemical works of
Brunner, Mond & Co., and be manufactured into salt at the Salt Union’s
works at Weston Point.
Compared with the other salt-making centres, the record of Middlewich
is of slight importance, and although the ancient town boasts an
honourable place in the history of the Cheshire Wiches, it now takes a
secondary position among the salt-producing districts.
Lawton, in the south-eastern corner of the Cheshire salt region, is
a comparatively modern entrant into the local industry, for although
the place is of historic importance as the scene of the discovery of
the bottom bed of salt in 1779, white salt has only been manufactured
there for something over 130 years. The deposits, which are found at
a considerable height above sea-level, are of great but undefined
magnitude, as the lowest strata has been bored through for a thickness
of 72 feet, without penetrating the formation. The rock salt here
was acknowledged to be purer than any previously encountered in
Cheshire, and the brine derived therefrom, containing 26·100 chloride
sodium by weight, yields on evaporation an exceptionally high class
of white salt. The Commercial Salt Company, Ltd., which was formed
to work the Hodgkinson Patent Salt-making Process, to which further
reference must be made later, have their works at Lawton, where they
are most conveniently situated in the important matters of transport
and fuel, being on the canal which brings them nearer to the markets
of the Midland Counties than any other salt works in the country, and
obtaining their coal from workings within two miles of the property.
The rock salt formation is so vast that the supply of brine, if not
actually inexhaustible, will allow of an enormous production of salt
for many generations to come. The output of white salt at Lawton for
nearly a century and a half has not appreciably depleted the deposits
and is not at present being drawn upon, as the Commercial Salt Company
are pumping from an excellent “brine run” which is pumped without the
damage to property and subsidence of land that have occurred in other
parts of the Cheshire salt districts.
The chronicle of the salt industry of Winsford is one of the romances
of commerce. Until the river Weaver was made navigable, the Winsford
salt manufacture was limited to the output of only four pans of
unrecorded dimensions, which were probably worked by Middlewich makers.
In 1758, the first year in which the Winsford shippings were recorded
separately, the export of white salt was 1,055 tons. By the end of the
century, Winsford sent 44,384 tons down the river Weaver, and, in the
year 1850, their shipments had increased to 324,249 tons. This output
had risen in 1880 to 794,824 tons of white salt. In the ensuing ten
years there was a slight increase, followed by a sharp decline (in
1890) to 501,548 tons, or a fall from the high-water mark of 834,306
tons in 1881, of no less than 332,758 tons. The decline in the Winsford
make of salt was not arrested by the formation of the Salt Union in
1888, and ten years later the output of white salt had decreased to
403,455 tons, and the export of rock-salt from Winsford, which had
recommenced with an output of 141 tons in 1856 and risen to 28,236 tons
in 1886, ceased in 1898.
CHAPTER IV
DEVELOPMENT OF BRINE PROCESSES
It has been said that _De Re Metallica_ of Georgius Agricola, published
in 1556, was regarded as the standard text-book on the subject for
nearly two centuries, and in that long period the method he describes
of salt-making by the artificial evaporation of brine underwent no
material change. But from the last half of the seventeenth century,
various attempts were made to effect improvements in the open-pan
process in this country, and the history of these endeavours is
set forth in a sequence of interesting publications. Among the
most important of these is an article, which was printed in the
_Philosophical Transactions_ of the Royal Society of England, in 1669,
in which Dr. William Jackson, in the form of a catechism, gives a
number of particulars concerning the salt springs of Nantwich and the
ways of salt-making as practised in that town. It appears from this
account that each of the salt houses was still furnished with six
leads, but one learns that this number of leads had, in the case of
the majority of the salt-houses, been converted into four iron-pans,
rather more than 3 ft. square by about 6 in. deep, and containing the
same quantity of brine as was previously distributed among the six
leads; while still more recently the four pans had been again changed
into two larger pans, and some salt-makers had re-fashioned these two
receptacles into one great pan. The description which Dr. Jackson gives
of the process is so concise and lucid that it may be reproduced here
without the alteration of a word. The question that he propounds to
himself is--
“What is the manner of their (the salt-makers) work? or what time of
boiling the salt water? Whether they use any peculiar thing to make it
granulate, and, if so, what that is?”
In the course of his reply, he says: “They use for their fuel pitcoals
brought out of Staffordshire. These pans are set upon iron bars,
bricked in very close. They first fill their pans with brine out of
the pit: which comes to them in several wooden gutters: then they put
into their pans amongst the brine, a certain mixture, made of about
20 gallons of brine, and two quarts of calves’, cows’, and, chiefly,
sheep’s blood. Of this mixture they put about 2 quarts into a pan that
holds about 360 quarts of brine: this bloody brine at the first boiling
of the pan brings up a scum which they are careful to skim off: they
continue their fire as quick as they can till half the brine be wasted,
and this they call boiling upon the fresh. But when it is half boiled
away, they fill their pans again with new brine out of the ship (so
they call a great cistern by their pan sides, into which their brine
runs through the wooden gutters from the pump, that stands in the pit)
then they put into the pan two quarts of the mixture following: they
take a quart of white of eggs, beat them with as much brine, as before
was done with the blood; and thus that which they call the whites is
made. As soon as this is in, they boil sharply till the second scum
arise: then scum it off as before, and boil very gently till it corne;
to procure which, when part of the brine is wasted they put into each
pan of the size aforesaid, about a quarter of a pint of the best and
strongest ale they can get: this makes a momentary ebullition, which
is soon over, and then they abate their fires yet not so but that they
keep it boiling all over though gently: for the workmen say that if
they boil fast here, it wastes their salt. After all their leach brine
is in, they boil gently till a kind of scum comes on it like a thin
ice: which is the first appearance of the salt: then that sinks and the
brine everywhere gathers into cornes at the bottom to it, which they
gently rake together with their loots, this they continue till there is
but very little brine left in the pan: then with their loots they take
it up, the brine dropping from it, and throw it into their barrows,
which are cases made with flat cleft wickers, in the shape almost of a
sugar loaf, the bottom uppermost. When the barrow is full they let it
stand so for an hour and a half in the trough where it drains out all
the leach brine, then they remove it into their hothouse behind their
works made there by two tunnels under their pans, carried back for
that purpose. The leach brine that runs from the barrows they put into
the next boiling, for it is to their advantage being salt melted and
wanting only hardening.
“This work is performed in two hours in the smaller pans, which are
shallower, and generally boil their brine more away: wherefore their
salt will last better, though it does not granulate so well, because
when the brine is wasted, the fire and stirring breaks the cornes.
But this salt weighs heavier and melts not so soon: and therefore is
bought for many sales to a distance. But in the greater pans, which
are usually deeper, they are above half an hour longer in boiling;
but because they take their salt out of their brine, and only harden
it in their hothouse, it is apter to melt away in a moist air: yet of
this sort of salt the longer the grain is, the longer it endures: and
generally this is the better granulated and the clearer, though the
other be the whiter. And I think it is rather the taking of the salt
out of the brine before it is wasted, that causes the granulating of
it, than the ale, to which the workmen impute it.
“They never cover their pans at all, during the whole time of boiling.
They have their houses like barns open up to the thatch with a
cover-hole or two to vent the steam of the pans.”
[Illustration: THE GREAT CANAL-BURST AND LANDSLIP, OWING TO SUBSIDENCE
NEAR NORTHWICH, 21ST JULY, 1907]
On the subject of the supply and quality of the brine obtained at
Nantwich and Middlewich, Dr. Jackson explains that the springs are rich
or poor in a double sense, as a spring may be rich in salt but poor in
the quantity of brine it affords. Thus, the chief pit at Middlewich
contained a rich brine yielding a full fourth part of salt, but the
supply was so meagre that the inhabitants were “limited to their
proportions out of it,” and their requirements were made up out of
pits furnishing a weaker brine. The pit at Nantwich was so plentiful
as to supply all the salters, but while the brine contained only a
sixth part of salt, “such quick use of it extremely strengthens the
brine, perhaps to a degree little less than that of Middlewich pit.” In
support of this statement that freshly drawn brine is richer than the
liquor that has stood for some days in the pit, Dr. Jackson testified,
as the result of personal experiment, that “a quart of brine, when the
pit has been drawn off three or four days first, to supply five or
six wich-houses, has yielded an ounce and a half more of salt than at
another time, when it has had a rest of a week or thereabouts.”
In the Droitwich locality of Worcestershire, the quality of the
brine closely resembled that of the Cheshire salt springs. In the
account by Dr. Thomas Rastel, published in 1678 in the _Philosophical
Transactions_, the writer says: “In the great pit at Upwich, we have
at once three sorts of brine, which we call by the names of first-man,
middle-man, and last-man, these sorts being of different strengths. The
brine is drawn by a pump: that which is in the bottom is first pumped
out; which is that we call first-man, etc. A quart measure of this
brine weighs 29 ounces troy, but of distilled water only 24 ounces.
This brine yields about a fourth part of salt; so that four tons of
brine make about a ton of salt. The other two sorts less, or 28 ounces.
And the pit yields 450 bushels of salt per day. In the best pit at
Netherwich a quart of brine weighs 28 ounces and a half; this pit is 18
feet deep and 4 broad, and yields as much brine every 24 hours as makes
about 40 bushels of salt. The worst pit at Netherwich is of the same
breadth and depth as the former: a quart of brine out of which weighs
27 ounces and yields as much brine daily as makes about 30 bushels of
salt.”
Although Dr. Rastel’s account of the salt-making methods in use at
Droitwich coincides with that employed about the same period in
Cheshire, he explains one or two minor variants and the reason of their
adoption. “The vats we boil the brine in,” he writes, “are made of
lead, cast into a flat plate 5 feet and a half long and 3 feet over:
having the side and ends beaten up, and a little raised in the middle,
which are set upon brickwork called ovens, in which is a grate to make
the fire on, and an ash-hole which we call a trunk. In some seals are 6
of these pans, in some 5, some 4, some 3, some 2. In each of these pans
is boiled at a time as much brine as makes 3 pecks of white salt. For
clarifying the salt we should have little need, were it not for dust
accidentally falling into the brine. The brine of itself being so clear
that nothing can be clearer. For clarifying it, we use nothing but the
whites of eggs, of which we take a quarter of a white, and put it into
a gallon or two of brine, which being beaten with the hand, lathers
as if it were soap, a small quantity of which froth put into each vat
raises all the scum, the white of one egg clarifying 20 bushels of
salt, by which means our salt is as white as anything can be: neither
has it any ill savour, as that salt has that is clarified with blood.
For granulating it we use nothing at all, for the brine is so strong
of itself, that unless it be often stirred, it will make salt as large
grained as bay-salt. I have boiled brine to a candy height, and it has
produced clods of salt as clear as the clearest alum, like Isle of May
salt: so that we are necessitated to put a small quantity of rosin into
the brine, to make the grain of the salt small.”
“If it is asked why we use not iron pans as in Cheshire,” Dr. Rastel
concludes, “I answer there have been trials made of both forged iron
pans and cast iron. The former the strength of the brine so corrodes,
that it quickly wears them out, the latter the brine breaks.”
The first serious attempt to effect a real improvement in the making of
salt from brine was communicated to the Lords of the Admiralty in 1746
by Thomas Lowndes, and under the title of “BRINE SALT IMPROVED or the
Method of Making Salt from Brine, that shall be as good or better than
FRENCH BAY-SALT.” It was published in the same year in a handsomely
printed, block-type brochure of 40 pages by S. Austin, of Newgate
Street, Lowndes, who had spent his infancy in Middlewich and had
acquired in his youth a thorough acquaintance with the Cheshire manner
of salt-making, employed several years in travelling in France, during
which he studied the process employed in the making of salt by solar
evaporation from sea-water in the neighbourhood of Rochelle. At this
time the bay-salt of Rochelle was regarded by merchants, victuallers,
and fishermen as the best in Europe. He afterwards visited Holland for
the purpose of ascertaining why the Dutch white herrings were superior
to those cured in England, and he learned that the cause was explained
by the method employed by the Dutch in purifying their salt. Armed with
the knowledge he had acquired in France and Holland, and allowing for
the difference between the French, Dutch, and English brines, Lowndes
offered to enter into an agreement with the Admiralty to supply them
with a better article than the French bay-salt, made by the following
process--
“_Let a_ Cheshire _salt-pan_ (which commonly contains about eight
hundred gallons) _be filled with Brine, to within about an inch of the
top; then make and light the fire; and when the Brine is just lukewarm,
put in about an ounce of blood from the butcher’s, or the whites of two
eggs; let the pan boil with all possible violence; as the scum rises
take it off; when the fresh or watery part is pretty well decreased,
throw into the pan the third part of a pint of new ale, or that
quantity of bottoms of malt-drink; upon the Brine’s beginning to grain,
throw into it the quantity of a small nutmeg of fresh butter; and when
the liquor has sailed for about half an hour, that is, has produced a
good deal of Salt, draw the pan, in other words, take out the Salt._
By this time the fire will be greatly abated, and so will the heat
of the liquor. _Let no more fewel be thrown on the fire; but let the
Brine gently cool, till one can just bear to put one’s hand into it;
keep the Brine of that heat as near as possible; and when it has worked
for some time, and is beginning to grain, throw in the quantity of a
small nutmeg of fresh butter; and about two minutes after that, scatter
throughout the pan, as equally as may be, an ounce and three quarters
of clean common Allom pulverized very fine; and then instantly, with
the common iron-scrape-pan stir the Brine very briskly in every part of
the pan, for about a minute; then let the pan settle, and constantly
feed the fire, so that the Brine may never be quite scalding hot, nor
near so cold as lukewarm; let the pan stand working thus, for about
three days and nights, and then draw it._
“The Brine remaining will by this time be so cold, that it will not
work at all; _therefore fresh Coals must be thrown upon the fire, and
the Brine must boil for about half an hour, but not near so violently
as before the first drawing; then, with the usual instrument, take out
such Salt as is beginning to fall, (as they term it) and put it apart;
now let the pan settle and cool. When the Brine becomes no hotter, than
one can just bear to put ones hand into it, proceed in all respects
as before; only let the quantity of Allom not exceed an ounce and a
quarter. And in about eight and forty hours after draw the pan._”
This process, as will be seen, involved the use of much slower fires
than were usually employed in Cheshire, and allowed the liquor to
simmer instead of boiling for a longer period. For this purpose, Mr.
Lowndes proposed to use a large proportion of cinders in his furnaces,
“since long boiling with great fires not only deprives salt of its
spirit and strength, but causes its grain to become loose and soft,
since cinders are better than coals in preserving a constant, equal,
and gentle heat.” In order to correct the ill-effects suffered by the
salt through being made in an enclosed, intensely hot room, filled
with steam and smoke, he had recourse to the use of alum, which, he
claimed, would restore to the salt its “natural cubical shoot and give
it a proper hardness.” He further claimed that by this process the
hot-houses or drying-houses could be dispensed with, waste in carriage
would be avoided, and the pans would last three times as long; while,
in order to anticipate the inevitable objections of the salt-makers
and dispel the pretended difficulties that the workmen would find in
executing his directions, the inventor explained that he had been
careful to accommodate his process, as near as possible, “to the
present practice in Cheshire.”
At the request of the Admiralty, the College of Physicians conducted
several examinations of salt made by the Lowndes process, and reported
that it was “in all respects, a strong and pure salt, equal at least,
if not preferable to any we are acquainted with.” On the strength of
this testimonial, Mr. Lowndes applied to the Admiralty to allow him
a six months’ trial to prove the goodness of his salt for domestic
purposes, twelve months to prove its excellence for the purpose of
the Fishery of America, and two years in which to prove its efficacy
in preserving beef and pork for the Royal Navy. If in this series of
tests it should be proved that salt made by his process equalled French
bay-salt, he proposed that they should pay him a total sum of £7,000,
and should the trials demonstrate the slightest inferiority, he would
be content to make his country a present of his labours. When the
Admiralty declined to enter into negotiations with him, Mr. Lowndes
laid his scheme before the House of Commons, which petitioned the King
to instruct the Admiralty to make the tests on the inventor’s terms,
but the sudden death of Lowndes in 1748 closed the controversy.
But the determination to bring the art of salt-making to “greater
perfection” was not abandoned, although, as Dr. William Brownrigg
admitted, the success achieved by Thomas Lowndes was thought by
some people “to supersede the necessity of any further attempts for
improving or extending our salt manufacture.” Brownrigg commended
Lowndes’s method and testified to the purity and strength of his salt
which had been exhibited before the College of Physicians, but he
maintained that by other methods a purer and stronger salt might be
made at a less expense. In point of fact, Dr. Brownrigg’s objection
to the Lowndes’ method was that it was applied only to salt made from
brine, or a solution of English rock-salt often prepared with impure
water, and that the salt so produced, in his opinion, was inferior to
marine salt. Brownrigg, only half realizing Lowndes’s intention, would
appear to have grasped the fact that his process aimed at economy of
fuel combined with uniformity in the degree and distribution of heat,
but he does not seem to have appreciated the value of the improvement
anticipated therefrom.
It must by this time have become evident to scientific investigators
and practical salt-men that the solution of the problems of economical
manufacture and increased output lay in the application and regulation
of heat. Christopher Chrysel, of Leipsic, after fourteen years of
“great industry, much pains, and cost” spent in the practice and study
of salt-making in Cheshire, published the result of his labours in
1787. Chrysel claimed that by his method “with the least Fire and
Coal the most Salt can be made and the greatest Profit received such
as in no other way can possibly happen,” but curiously enough the
improvement for which he obtained a Royal Patent, was primarily based
upon a more advantageous arrangement of the brine pans, while the
improvement effected in the furnace was treated as a matter of only
subsidiary importance. Chrysel demonstrated his method at Bye Flat,
near Northwich, in Cheshire, in June, 1776. The experiment was carried
out in the presence of witnesses, the same pan was used in testing both
the old and the new methods, the same two salt-boilers were employed in
conducting both operations, and the amounts of fuel consumed and salt
produced were carefully weighed and attested. The results were recorded
in the following report furnished by the Liverpool Agent of Mr.
Richard Kent’s salt-works at Bye Flat--
[Illustration: A SALT STORE-SHED]
“In three ‘firings’ of 2 Furnaces under a salt pan set up on the old
plan ten years ago and constantly worked till the present time--24 feet
long: 15 feet broad and 12 inches deep--filled with Brine three times
in a half week, and boiled down each time in 24 hours and the salt
drawn out there was burnt 5½ tons of Coal and made 7 tons 31 bushels,
or 155½ cwts. of salt.
“After the experiment the Patentee, Mr. Christopher Chrysel, set up
the same pan on his improved Patent Method, and then in three similar
firings in half a week as before there was only burnt 3 tons 5 cwt. of
coal and made 8 tons 2 cwts. or 162 cwts. of salt=2 tons 10 cwts. of
salt per ton of fuel.”
Chrysel says in his treatise that the pan mentioned in his
experiments--24 ft. long, 15 ft. broad, and 12 in. deep--will be
regarded by his German readers as of phenomenal bigness, but he
explains that in England it is looked upon as only a medium-sized
receptacle. The pans in use in Cheshire at this period were of various
sizes, but the tendency was to introduce pans of increasing dimensions.
“Indeed I can with all truth say,” he writes, “that in England I have
seen with my own eyes, pans two, three and four times as big (as the
one he used at Bye Flat) and have measured them with my own hands, and
have proved each one designedly and have seen and marked and become
persuaded that from large salt pans the greater advantage and the most
noted cheapness in the manufacture of salt depend and proceed.”
In the course of his experiments with pans of all sizes, he proved that
in a small pan, 8 ft. square and 9 in. deep, heated with one furnace,
he obtained in five weeks a clear profit of £35 15s. 2d., while in
one pan, compounded out of five of the small pans, and heated with two
furnaces, the profit of one week’s working was £42 15s. 5d., or a net
additional profit of £7 0s. 3d., and the saving of four weeks in time
and labour.
He further experimented with three of the largest pans for one week,
with the following results--
“The first--36 by 25 feet and 13 inches deep holding 975 cubic feet of
Brine--burnt in 3 Furnaces in one week 12 tons of coal and made 32 tons
2 cwts. of salt.
“The second--40 by 27 ft. and 13 inches deep holding 1170 cubic feet of
brine--burnt in 3 Furnaces in a week 15 tons 18 cwts. of coal and made
34½ tons of salt.
“The third--52 by 26 feet and 13 inches deep holding 1464 cubic feet
of Brine--burnt in 4 Furnaces in one week, 24 tons of coal and made 62
tons of salt.”
Chrysel is himself amazed that pans containing 360, 900, and even 1,400
cubic feet of brine can be boiled into salt in the same space of time,
and he is feign to admit that “up to now, nobody, to my knowledge,
has proved what length, breadth, and depth of pan is calculated to
make the most salt with the least consumption of coal. Consequently
everywhere are to be found many different pans, and other varieties are
continually being tested. And I myself cannot feel that I am capable
of deciding the question, nevertheless I will, from my experience and
conscientious conviction, say what I consider is the best, cheapest,
and most reliable pan for this purpose.”
After long search, and close inquiry in numerous salt-works, and as
the result of his study of salt-making in pans of every size, Chrysel
came to the conclusion that a single pan--“26 feet long, 18 feet
broad, and 12 inches deep, with two furnaces, in a roomy salt-works
with sufficient room for the workmen and baskets on both sides of the
pan”--was to be preferred to all others. But this considered judgment
was amended after further application to the problem by advocating
an increase in length without changing the breadth of the pan. His
ultimate verdict was in favour of a pan 52 ft. long, 18 ft. broad,
and 1 ft. deep, with a capacity of 936 cubic feet of brine, equipped
with two furnaces, and he declared that this pan, producing about 638
cwt. of salt per week, at a cost of £10 5s. 6d. for fuel, and selling
for £127 15s. 6d., and giving a profit of £117 10s. was “the perfect
article.”
Although, as I have pointed out, Chrysel’s patent was principally
concerned with the arrangement of the brine pans, which were so
arranged as to obtain the maximum amount of heat from the fuel consumed
in the furnaces, in the course of his experiments he evolved an
improved, if by no means a perfect, furnace. The peculiar nature of
the superiority effected was based on the common knowledge that it is
the natural tendency of fire heat and smoke to escape into the open
air and disappear. He proceeds: “If, however, they are confined and
shut up in a furnace under a salt pan they still require an opening to
escape to the chimney else the fire cannot burn and is extinguished.
If however the opening and place of exit into the draughts and chimney
is too large and wide, as it is generally, and particularly under salt
pans, not only will the draught of Air cause Wood and Coal to be more
rapidly consumed and changed into Ashes which will choke the fire but
also the fireheat and smoke will, by the draught of the air, hasten
into the draughts and chimney, and the bottom of the pan will hardly be
touched and scarcely half the work be done. On the contrary, if the
opening and exit into the draughts and chimney has a proper proportion,
according to the different sizes of the Pans and to the requisite Fire
in the Furnace under the pan, the Fireheat and Smoke will be longer
contained under the pan and that, steadily coming from the Furnace,
will be increased and strengthened, so that double work under the pan
will result, and wood or coal will not so rapidly be burnt to ashes but
last longer and consequently do more work. All that is required in this
is to calculate the mathematical proportion between the different sizes
of the pans, the Furnace and the Fires and between the opening and Exit
into the draughts and chimney, and to apply it.”
It will be recognized that both Lowndes and Chrysel were on the way
to the solution of the problem of the perfect salt-making plant when
they devoted themselves to the improvement of the furnace, but another
century and a half was to elapse before the secret that eluded their
efforts should be revealed. The luckless Furnival, some fifty years
later than Chrysel, approached nearly to the goal to which they were
all striving, and he, in common with his forerunners, had his share
of the savage jealousy and persecution that the salt-men have ever
visited upon those who venture into the lists with them. “No malice
has been wanting to bring a disreputation upon my salt; and every
wicked art will be practised to render its virtues ineffectual. The
Salt Commissioners are my avowed enemies; for the miscarrying of my
attempts will be their gain.” Thus wrote poor Lowndes, and Chrysel had
similar grounds for complaint. “Before the above proof (the result of
his experiment at Bye Fleet) was made openly, nobody believed in the
anticipated saving,” he says, “but everybody doubted and some declared
it to be impossible. After, however, the thing was made known,
everybody on the contrary was in a state of wonderment. In a short time
wonder was changed into envy, ill-will and malice, and many attempts
were made to suppress me and destroy my patent, although it was not
possible for any one to point out any failures or errors.” We shall see
presently how the salt-men dealt with their successor, William Furnival.
Henry Holland, writing in 1808 on “The Production of Salt Brine,”
furnishes some reliable details concerning the manufacture of
brine-salt as it was conducted in Cheshire at the beginning of the
nineteenth century. According to this authority: “The pans used in
Cheshire, for the evaporating of the brine, are now made of wrought
iron. The dimensions of these vary very much; but, in general, those
of modern erection are considerably larger than what were in use a few
years ago; and they usually contain from 600 to 800 superficial feet.
One or two pans of still larger dimensions have been erected, each
containing nearly 1,000 feet. Their usual form is that of an oblong
square, and their depth from 12 to 16 inches. To a pan containing 600
to 800 superficial feet, there are usually three furnaces, from six
and a half to seven feet long, and 20 to 24 inches wide. The grates
are from two and a half to three feet from the bottom of the pan. The
furnace-doors are single, and there are no doors to the ash-pits.
“The different pans are usually partitioned out from each other, and
there is a separate pan-house to each pan. Within this pan-house, at
one end is the coal-hole; the chimney occupies the other end, there
is a walk along the two remaining sides of the pan, five or six feet
wide; and between these walks and the sides of the pan-house, which
are generally of wood, long benches four or five feet wide, are fixed,
on which the salt is placed in conical baskets to drain after it has
been taken out of the pan; a wooden or slated roof is placed over the
pan-house, with louvres to allow the steam to pass freely out.
“The manufacture is conducted in several different ways, or rather
heat is applied in various degrees, to effect the evaporation of the
water of solution; and according to these different degrees of heat,
the product is the stoved or lump salt; common salt; the large grained
flaky; and large grained or fishery salt.”
In the making of stoved salt, the brine was brought to a boiling
heat--which in brine fully saturated is 226 degrees of Fahrenheit--and
the pan was twice filled in the course of twenty-four hours. In the
making of common salt, the brine was first brought to boiling heat,
for the double purpose of expediting saturation and clearing the brine
of any earthy contents, and then, moderating the fires, the process
of crystallization was completed with the brine heated to 160 or 170
degrees of Fahrenheit. The pan in which common salt was made was filled
only once in twenty-four hours. The large grained, flaky salt was made
with an evaporation conducted at the heat of 130 or 140 degrees, and
the pan was filled once in every forty-eight hours; while in the case
of fishery salt, the brine was brought to a heat of from 100 to 110
degrees of Fahrenheit, and five or six days were required to evaporate
the water of solution. In the course of these several processes,
various additions were often made to the brine, with the view of
promoting the separation of any earthy mixture, or the more ready
crystallization of the salt. These additions varied in different works,
and many of them seem to have been made from ill-founded prejudices
without any exact idea as to their probable effects. The principal
additions made at various times were acids, animal jelly and gluten,
vegetable mucilage, new or stale ale, wheat-flour, resin, butter, and
alum.
Holland believed that the addition of acids to the brine was an
innovation based upon the mistaken idea that the use of acid accounted
for the superiority of the Dutch salt, but at the time at which he
wrote the practice had been discontinued in Cheshire. Animal jelly
and gluten for clearing the brine and promoting the separation of the
earthy contents, were much used in preference to blood, which, while
excellent for the purpose when fresh, was difficult to procure in
sufficient quantity and to preserve from putrefaction. White of eggs,
glue, and jelly procured by boiling cows’ and calves’ feet, were also
found to answer perfectly well for the purpose of clarifying brine, but
the use of new or stale ale and beer grounds as a brine clarifier, had
been abandoned as inefficacious by Cheshire salt-men. Dr. Brownrigg
was of opinion that salt-boilers had little to plead in favour of the
addition of butter during the evaporation process, beyond immemorial
custom, but Holland considered the salt-makers had ample grounds for
their belief that butter assisted the granulation of the salt and made
the brine “work more kindly.” On the question of the addition of alum
opinions varied. Lowndes ascribed the superiority of his salt to the
use of alum, but Brownrigg declared that “the goodness of Mr. Lowndes’
salt does not seem to be owing to the alum with which it is mixed, but
may be attributed chiefly to the gentle heat used in the preparation.”
[Illustration: WITTON BROOK, NORTHWICH. SUBMERGED TRACT OF AGRICULTURAL
LAND]
Holland combated the general impression obtaining at the time, that
salt formed from the same brine varied by the application of different
degrees of heat, not only in external appearance but also in quality,
and the equally prevalent idea that salt formed from natural brine
was inferior in its power of preserving animal flesh to bay-salt. He
proved by quotation and experiment that such prejudices were entirely
unfounded, and proceeded to show that the action of bay-salt is exactly
similar to that of the large-grained salt, and that neither variety
has any advantage over the salt prepared by a boiling heat except
in the size and compactness of its crystals and in its containing a
somewhat smaller proportion of the water of crystallization; and as
the large-grained fishery salt is more than equal to the bay salt in
these important points, it at least equals the latter in its power of
preserving animal flesh or provisions.
The first person who introduced steam heat into the manufacture of
salt, and, in so doing, anticipated the revolutionary improvements
which were achieved some three-quarters of a century later by the
Vacuum System and the Hodgkinson Patent Salt-Making Process, was
William Furnival. For our knowledge of the intentions and achievements
of this bold and persevering innovator we have to rely almost entirely
upon his “Statement of Facts, Humbley and Respectfully submitted to
the Consideration of His Majesty, His Majesty’s Ministers, and Both
Houses of Parliament.” In this document we have a story of oppression,
conspiracy, and persecution which the author describes as “unparalleled
in free England,” and since his narration of the treatment he endured
has never been refuted, we must conclude that the gist of what he
writes is substantially true. It is to be regretted that in this
only available account of his activities, Furnival is so intent upon
exposing the wrongs to which he had been subjected that he omits to
furnish us with a detailed description of his process. We know that in
1823 Furnival erected works at Droitwich and commenced making salt,
and we have his assurance that his patent answered every expectation
he had formed of it. Moreover, its working was investigated by Messrs.
S. Fowler, Fardon & Co., who, on 17th April, 1824, certified that
the advantages of the Furnival method over all existing processes,
consisted--
“Firstly.--In the saving of fuel which may be stated at about one-half.
“Secondly.--In the production of twice the quantity of salt, as usually
made in vessels of the same size, in a given space of time.
“Thirdly.--In the superior quality of the salt, arising out of the
regular distribution of heat to the bottom of the brine pan.”
In April, 1825, Furnival disposed of his salt property at Anderton,
and three years later, to a month, he bought property at Marston for
£1,550. On this ground he erected works covering an area of about
twelve acres, and installed some three miles of pannage at a cost of
upwards of £135,000, capable of producing some 130,000 tons of salt per
annum. He subsequently bought and started to erect works intended, when
finished, to occupy nearly six acres of ground at Marston. He asserted
that these Wharton and Marston properties were the only two in the
kingdom possessing the peculiar advantages of inexhaustible supplies
of fully saturated brine and dry rock-salt on the same premises, and
he claimed that he could not only deliver rock-salt at fully 25 to 30
per cent. less than any other mine in the country, but, further, that
the salt made on his principle was admitted to be superior in quality,
owing to the regular distribution of heat, by which more uniform and
superior crystals were produced. In the autumn of 1829, he opened
negotiations in two separate quarters to lease on royalty certain
portions of his salt-works at Wharton, and two committees, each
consisting of three men, were appointed by the prospective tenants to
investigate the system. On 22nd August, 1829, the two committees drew
up a joint report, from which I extract the following--
“The first committee entered upon the investigation on the 15th August,
1829; remained on duty eight hours; was then relieved by the second
for the like period, and so continued the investigation, alternately
superintending the weighing and delivery of the coals and salt, and
taking note of the temperatures every hour.
“The following is the result of working for 162 hours, a steam boiler,
constantly fed with brine, the specific gravity from 23 to 25·100ths.
Length of the boiler, 20 ft.; width, 8 ft.
A triangular flue pan, 80 ft.; width, 8 ft.
A triangular steam pan, 101·6 in.; width, 8 ft.
forming a surface of 1,612 superficial ft. of brine.
The quantity of coal consumed was 8½ tons.
The quantity of fine salt produced was 356 cwt.
Ditto of common and fishery 404 „
--------
Making 760 cwt.
========
“Being a product of four and a half tons of salt for every ton of coals
consumed.”
It will be convenient here to explain what became of these several
Furnival properties, and then describe very briefly the stages which
led to the inventor’s incarceration in Horsemonger Lane Gaol and
caused him to address his Statement of Facts to the Government. In
April, 1825, he sold his works at Anderton to the British Rock and
Salt Company, which continued to ship salt until 1829. The Marston
property appears to have been worked until 1847. The Wharton works
were managed by Trustees until 1839, when they were taken over by the
National Patent Salt Company, which became one of the most important
firms in the Winsford trade. In 1875, Justice Manisty, the surviving
leaseholder, transferred his interests to Stubbs Brothers, who, in
1888, disposed of the business to the Salt Union.
Furnival had no sooner established himself as a salt-maker at Anderton
than the old salt proprietors, “who had contrived in the past to ruin
all, or any one who should dare to enter the lists against them,”
became seriously alarmed at the apparent magnitude of his plans and
the great improvements which threatened both their exorbitant profits
and their hitherto unchallenged monopoly. Furnival, to employ a
colloquialism, proceeded to “back himself both ways.” Having more than
once proved his strength by breaking up “the Coalition” (which the old
proprietors had formed to regulate the output and price of salt), and
bringing down the price of common salt from 20s. to 8s. per ton, he
offered to erect his patent apparatus at his own cost and risk on the
works of his wealthy rivals, and to allow them two-thirds of the saving
effected by its application. According to Furnival’s unsupported but
uncontradicted account, they ridiculed his offer, declaring that they
wanted none of his patents, that they could command their own profits
in defiance of him, and that they would never sanction any improvements
or innovations in the trade.
Furnival, who had secured patents for France and the Netherlands,
thereafter gave his English competitors a rest and proceeded to erect
salt-works at Rotterdam and Ghent capable of taking nearly 60,000
tons of rock salt annually from the British market. But the English
salt refiners prompted their Dutch and Belgian _confrères_ to bring
official discredit upon the enterprise, and Furnival and his partner
were compelled to abandon their works, which had cost them £13,000 to
erect, and to forgo the £33,000 they were to have received for their
patent rights.
Furnival returned to England and set up his salt-works at Wharton,
where he “produced some of the finest rock-salt in the kingdom.” The
old proprietors decided that no sacrifice was too great that would
have the effect of crushing this competitor. They lowered the price of
rock-salt 50 per cent., and kept manufactured salt so low that every
establishment was worked at a loss. A meeting of proprietors, convened
to consider the situation, resolved that while “they deeply lamented
the low price of salt, they considered, at the same time, that it would
not be prudent to raise the price until Mr. Furnival was disposed of.”
The salt manufacturers admitted, in a circular published in 1829, that
this cutting-out operation had, in four and a half years, involved the
trade in a loss of £282,194 14s., but it had the effect of frightening
away Furnival’s financial supporters, and landed him in further
misfortunes.
[Illustration: WORKING IN DANGEROUS GROUND AFTER SUBSIDENCE, DUNKIRK
LAKE, NORTHWICH]
In 1826, Furnival had entered into a contract with a Peter Bouvain
to erect a salt-works in the Isle of Rhé, but the month that was
required to prove the capabilities of the patent plant was sufficient
to demonstrate the commercial worthlessness of the Frenchman, and
Furnival cut his loss and returned to England. Bouvain brought a
claim against him for the loss of prospective profits and obtained a
judgment for £8,000, against which Furnival appealed to the Court of
Cassation in Paris. Before the case was heard, Furnival was inveigled
to the Netherlands by a forged invitation, purporting to come from a
wealthy Belgian salt-refiner, driven over the frontier, arrested in
France at the suit of Bouvain, and thrown into gaol. Finding that
legal redress was unobtainable, Furnival escaped from prison after four
months’ incarceration, and in January, 1830, was again in Cheshire.
He was engaged in a bitter and protracted altercation with his two
sets of tenants in the Wharton salt-works in August, 1832, when he
was arrested for the non-payment of his debt of £8,180 to Bouvain,
and lodged in Horsemonger Lane Gaol. In January, 1833, he brought
an action for perjury against Bouvain, who fled to France to escape
the warrant that was issued for his arrest, but this moral victory
brought Furnival neither release nor amelioration of his lot, and he
found himself “foully and unjustly charged by a band of conspirators,
defeated in every attempt to obtain justice, and left without a hope
or prospect of being able to vindicate himself, or extricate himself
from a confinement more close than that awarded to a felon.” The end
of Furnival need not occupy us; he came into the salt trade in 1822
with a sufficiency of financial backing, an unusual stock of confidence
and energy, and a patent which “created a sensation through the whole
salt trade”; we take our leave of him eleven years later in a debtors’
gaol--a victim to the methods which the Cheshire salt proprietors
invariably adopted in ridding themselves of an obtrusive competitor.
CHAPTER V
FORMATION AND EXTENT OF THE CHESHIRE DEPOSITS
The theories propounded and the conclusions arrived at on the
subject of the formation of the Cheshire salt beds do not differ in
any important particular from those which have been put forward,
investigated, and accepted with regard to rock-salt deposits in all
parts of the world, but, because of the enormous geologic and climatic
changes that have occurred in the English county since a salt basin
was in course of formation there, scientists were slower in accepting
those conclusions in respect of our home deposits than in the case of
the salt areas which are found in the Runn of Kutch, at Lake Elton, or
Black Gulph on the eastern side of the Caspian Sea.
The facts that the chief accompaniment of every known deposit of
rock-salt is clay, and that clay is deposited in water, formed the
basis of the erroneous theory that because salt is a deposit out of
water, and sea-water contains salt, all salt beds must have been
deposited in the sea. But salt does not mix mechanically with water and
has not been deposited like sedimentary rocks; it forms a solution, and
not until the solution becomes super-saturated does it crystallize out.
Now sea-water rarely contains more than 3½ per cent. of salt, and since
the solution must contain at least 26 per cent. of salt before the salt
will crystallize out, and, provided it is left from contact with the
air, a solution of this strength may be left for an indefinite length
of time without a single particle of salt depositing, the old theory
that all salt beds were deposited in the sea had to be abandoned.
The theory of the sea-water deposition of salt beds having been
disposed of, it was long a popular idea that the beds of rock-salt
owed their formation to volcanic action. Professor C. Thompson was
of opinion that some enormous electrical force had been at work in
its crystallization; Professor Silvestri found quantities of chloride
of sodium varying from 50 to 90 per cent. in different sublimations
in the lava which was erupted from Etna in 1863; Bunsen discovered a
considerable but less important sublimation of chloride of sodium in
the lava erupted from Hekla in 1854; and G. F. Rodwell and H. M. Elder
also recognized small traces of sodic chloride as one of the products
of volcanic action. In a paper contributed to the Manchester Geological
Society, in 1842, on “An Inquiry into the Origin of the Salt Field of
Cheshire,” so respected an authority as Ormerod stated his conclusions
as follows--
“(_a_) That from the lithological character of the accompanying
beds and partings, and from the regularity in the thickness of the
respective beds, as far as the same were now known, these salt beds
were, in his opinion, deposited from an aqueous menstruum, and had not
been injected.
“(_b_) That from the absence of marine remains, from the salt deposits
containing matter not found in the ocean, and from similar beds of salt
not being in any place known to have been formed from the ocean, he
considered that there were not satisfactory reasons for ascribing the
origin of the salt found in the new red sandstone of England to marine
deposits.
“(_c_) That from the minerals found associated with the salt, and
adjoining red sandstone rocks, being similar to those found together
with it in volcanic districts in other parts of the world; that from
former or present volcanic action being apparent at localities in
various parts of the globe, at which beds of salt of similar character
are found, and the origin of which can be evidently traced to that
cause, and from the salt beds in England being always found accompanied
by neighbouring traces of volcanic action, he considered that there
were satisfactory reasons for ascribing the origin of the salt fields
of England to volcanic agency.”
Ormerod was not only convinced that the Cheshire deposits were
the result of volcanic action which had impregnated neighbouring
lagoons and formed the aqueous menstruum from which those beds were
precipitated, but that these lakes lay in depressions of the upper
New Red Sandstone, and that the alternation of the strata of rock and
salt had arisen from subsidences, followed or accompanied by fresh
discharges of the same impregnating matter.
This theory is untenable, for beyond the fact that salt has been
ejected in volcanic eruptions there is practically nothing to support
it. Volcanic action is always accompanied by intense heat, and the fact
that the pure rock crystal is one of slow growth in a cool liquid, and
is not of rapid formation in a hot fluid, conclusively disposes of the
volcanic theory. Particles of chloride of sodium in volcanic ejections
were no explanation of the formation of huge deposits of rock-salt, and
since it was realized that salt in large quantity can only be obtained
from salt water, and that it cannot be got naturally from the sea, it
became evident that what man does in isolating tracts of sea-water to
produce salt by solar evaporation, must have been practised by nature
on an extensive scale in all ages. And as an isolated tract of salt
water is a salt lake, we are directed to the obvious conclusion that
all rock-salt formations have been deposited in salt lakes.
In support of this theory we have the evidence of the salt-forming
process that is now in operation in Southern Russia, America, and
India. It is evident that at one time the low-lying country to the
west and north of the Caspian Sea was part of that inland sea, and
that, when its surface was contracted by shrinkage, the retreating
water left behind it numerous swamps, which now form salt lakes, and
tracts of intervening land which, in the dry season, are covered with a
saline afflorescence. The large quantities of salt which, in ordinary
seasons are deposited in these salt lakes, are collected by the Russian
Government. In India there are many salt lakes, such as Lake Sambhur,
in Rajpootana, which in the rainy season has a length of from fifteen
to twenty miles, but in the dry season is only three or four miles
long, the remainder of its course consisting of a succession of small
salt pools alternating with stretches of salt-encrusted ground. In the
great desert of Mongolia many square miles of country are spread with
salt incrustations; and in America similar tracts are found which once
formed the beds of considerable lakes. In Nevada, at the sink of the
Carson River, is an area of five square miles which was once the bed of
a salt lake. The famous Great Salt Lake, between the Wahsatch Mountains
and the Nevadas in America, is the remains of a large inland sea which
once covered the district, and should the climate become drier than it
is now, the shrinkage, which went on for ages, will be resumed, and a
huge salt deposit will be formed.
The salt lakes in rainless districts soon dry up, and the salt, being
quickly deposited, is almost pure, but such instances are not usual,
and, in dealing with existing salt-depositing lakes, we find continual
references to the salt and clay mixtures, or alternations of the
deposits. Herr Cech tells us that the yearly layers of salt in Lake
Elton are separated from one another by a layer of black mud; beneath
the fourth layer is found black clay, and beneath this are further
layers of salt of a more solid quality. Schleiden, in speaking of
Lake Elton, says: “On this old salt is deposited a blackish mud layer
(salt clay) which separates the salt from the next succeeding layer.
In 1805 Göbel bored, in the very shallow lake, about 1½ miles from the
shore. He found forty-two distinctly separated layers of rock salt,
the uppermost from 1 to 4 inches thick, the lowest 9 inches thick. The
deeper he bored the more solid the salt was, and the more pure. At the
hundredth layer the salt was so hard that the iron tool broke.”
From the foregoing, which are among a great collection of accepted
data, it will be seen that, in whatever quarter of the world salt
lakes occur, the same characteristics are encountered, viz., salt
depositing on mud and covered by mud. Every shower of rain creates a
certain amount of mud or sand, and every brook and stream running into
the salt lakes during the rainy season brings in a certain quantity of
the same material. The mud represents the wet season of the year, and
the salt the dry season. The geological conditions must have been the
same when salt was deposited in Cheshire, and with the instances of
modern salt-forming regions before us, and the strata of the Cheshire
salt country to guide us, it must be concluded that the genesis of
rock-salt, modified by local circumstances, must have been the same
in every case. Indeed, in the face of the evidence, it seems certain
that the Cheshire beds of rock-salt have been crystallized out of the
saturated waters of salt lakes, and that their admixture of marl has
been caused by streams running into the lakes during the wet seasons,
and that the peculiar amorphous mixture of marl and salt known as
rock-salt is the result of the continual growth of pure salt crystals,
and their partial destruction by mud-bearing fresh waters.
This conclusion on the subject, which is now generally accepted, is
based on the theory that the Cheshire salt lake was situated in a
desert, or more probably a salty _steppe_, such as are found in the
region of the Caspian Sea, and that the climate was divided into wet
and dry seasons. The presence of rock-salt supports these ideas,
because the marls could only be formed in periods of heavy rainfall,
and the salt could only crystallize out in dry, water-evaporating
periods. It is further evident that the lake, though extensive in area,
was shallow, and that the dry seasons produced extensive shrinkages
and caused salt to form in the saturated water that remained in the
deeper parts, while the occurrence of the deep deposits in a shallow
lake is explained by the constantly varying elevation and depression
of the earth’s surface. The difficulty of explaining how the salt in
this lake could be renewed to enable the waters to go on depositing for
a geologic age is recognized, but it is no greater than that which is
presented by scores of existing salt lakes out of which thousands of
tons of salt are taken annually without causing any apparent diminution
in the salt which forms year by year. And when it is considered that,
in a lake having a probable area of from 500 to 1,000 square miles, the
known salt deposits do not occupy 50 square miles, and in many portions
contain 50 per cent. of marl, the difficulty does not seem to be
insuperable. It is, moreover, safe to conclude that, when the bar rose
that eventually cut off the Cheshire lake from the sea, it would be
many years before the high tides ceased to wash over it and replenish
the lake, and Dr. Ball’s theory as to the enormity of the tides that
occurred in past ages--owing to the moon being nearer to the earth
than at present--reveals a means by which the lake might continue to
receive fresh accessions of sea-water for many generations.
[Illustration: STREET-RAISING IN PROGRESS--HIGH STREET, NORTHWICH]
Irrespective of all theories, the outstanding fact remains that
enormous beds of salt were deposited in the Cheshire salt lake, and an
examination of the strata in the appended Northwich section will enable
the salt to tell its own history.
_Depth._ _Thickness._
Ft. in. Ft. in.
1 6 1 6 Soil.
9 0 7 6 Drift composed of brown sand mixed with clay
varying from 1 to 100 ft. in thickness.
27 0 18 0 Brown clay with greenstone, etc., boulders.
132 0 105 0 Marl in thin bands, brown and blue with thin
beds and streaks of gypsum to the rock head.
216 0 84 0 Rock-salt, top bed.
222 0 6 0 Upper blue marlstone mixed with brown, which
falls on exposure.
229 0 7 0 Brown marl and marlstone, with vein of red
rock-salt.
234 0 5 0 Lower blue marlstone, very compact, hard,
and does not fall on exposure.
(This forms the foundation for the
wedging-curb of the shaft cylinders.)
246 0 12 0 Marl and rock-salt mixed in about equal parts.
330 0 84 0 Rock-salt, bottom bed.
334 0 4 0 Brown and blue marlstone, with rock-salt.
417 0 83 0 Ditto with thin veins of rock-salt, ramifying
in various directions.
320 0 3 0 Rock-salt, almost pure.
501 0 81 0 Brown and blue marlstone, with thin veins of
rock-salt.
507 0 6 0 Rock-salt, almost transparent.
525 0 18 0 Hard blue marlstone, not sunk through.
The formation has only been bored through to a depth of 525 ft., where
we find an unpierced stratum, 18 ft. thick, of hard marl. Above it
are 6 ft. of pure rock-salt, then 81 ft., of marl with thick veins of
rock-salt, then 3 ft. of nearly pure salt, then 83 ft. of marl with
thin veins of salt, and above it 4 ft. of marl and salt. So far it is
evident that the wet seasons predominated, and that marl was deposited
far more extensively than salt. For a time, a cycle of dry seasons
prevailed; a great change occurred, and a bed of rock-salt, 84 ft. in
thickness, was deposited. In other parts, the bed of rock-salt varies
from 80 ft. to over 100 ft. in thickness, none of which is perfectly
pure, and not more than 20 ft. of it is sufficiently pure to be of
commercial use. The greatly changed seasons are indicated by these
formations. A portion near the bottom, containing less clay, shows
a less copious or less protracted rainfall, and these periods were
followed by wet seasons and the presence of much clay. After a time,
so much rain fell that for a period sufficiently long for about 30 ft.
of marl to deposit, practically no salt formed. Here and there in this
deposit are veins of salt, and as these are perpendicular and run as if
deposited in rifts or cracks of the marl, the salt doubtless belongs to
the next period, when another change occurred and another bed of salt,
varying from 50 to 80 ft. in thickness, was deposited. The whole of
this bed is fairly full of marl, and, for an untold period, marls were
deposited, covering up the rock-salt.
The cycles of greater or less rainfalls are traceable in the varying
preponderance of marls, in the crystallization of salt, and in the form
in which the rock-salt is found. Each minute cube starts as a crystal
from some independent point of rock salt, and these increase in numbers
until they form a mass of crystallization possessing no distinct lines
or features. Had the dry season continued for a long period a thick
mass of rock-salt would have been formed. The floor of the lake would
have been covered with salt crystals, like the crystal floor of a
mine, and the moment the rainy season commenced, and the brooks began
to bring in fresh water and mud, these crystals, being attacked by
non-saturated water, immediately lost their sharp angles and became
covered with a fine layer of mud. As soon as the crystals became
completely covered they ceased to dissolve, but the angles and cubes
disappeared, and a shapeless mass of mixed salt and mud was formed.
With the next dry season, crystallization again set in and another
crystal floor was produced, to be again destroyed by the succeeding wet
season. This constant growth and destruction of crystals went on for
ages, until the salt beds were formed and the water ceased to become
super-saturated.
Scientific exploration work and a great number of borings have enabled
us to form a fairly accurate estimate of the area of the Cheshire
salt-beds, except in the region to the north of the deposits, where
systematic examination has still to be undertaken. Without quoting the
exact locations of bore-holes and distances between them--particulars
which would convey little or nothing to the general reader--it may be
broadly stated that the proved salt area in the Northwich district is
about four square miles, while the increasing quantity of marl that
is mixed with the salt to the northward favours the probability that
the beds soon die out in that direction. The Winsford salt district
comprises an area of six square miles, while it is calculated, with
less preciseness, that the Middlewich, Nantwich, and Lawton districts
all contain large quantities of rock-salt. At the bore-hole at Marston,
which appears to be on the highest proved portion of the salt-bed, the
salt is found at 47 ft. below ordnance datum, and from this central
point the surface of the salt falls away gently in every direction.
Mr. James Thompson, a recognized local authority upon salt and
salt-mining, writing on the subject nearly fifty years ago, gave the
thickness of the upper bed of rock-salt at about twenty-five yards, but
that thickness was only maintained within a circle of about three miles
in circumference, beyond which he found that it thinned off rapidly on
the upper surface. The extent of the second or bottom bed, from which
all the rock-salt produced in Cheshire since 1780 has been extracted,
is less clearly defined, but it is known to underlie not only the whole
of the upper bed, but a further considerable area in all directions.
[Illustration: THIS ROAD WAS RAISED TWENTY FEET IN TWENTY YEARS. NONE
OF THESE BUILDINGS IS NOW STANDING]
Professor Thompson, in calculating the period of time that was required
to lay the salt contents comprised in these deposits, fixed upon an
inch in ten years as a fair estimate of the rate of progress at which
it was accumulated, and found that it must have taken 21,000 years to
lay 60 yds. of rock-salt. With this figure before us, it is interesting
to study the following calculation of the salt contents of the Cheshire
deposits and of the quantity of mineral that is extracted from the
interior of the earth in the form of brine to produce the salt that is
made in the Cheshire districts.
Calculating the Northwich salt area at 3 square miles or 1,920 acres or
9,292,800 square yards, and
Taking the upper bed of rock-salt at an average of 25 yds.
thick, we have 232,320,000 cubic yds. of rock-salt.
Taking the specific gravity of rock-salt at 2·125, a cubic yard
of rock-salt weighs 32 cwts., therefore weight of rock-salt in
upper bed
232,020,000 × 32 tons / 20 = 371,702,000 tons.
Taking the bottom bed as extending over the same area, but having a
thickness of 35 yds., we find in it--
9,292,800 × 35 × 32 / 20 = 520,396,800 tons,
or, in both beds together, 892,108,800 tons.
The Winsford district, taking the beds of rock-salt at an average
thickness of 65 yds., which is 5 yds. less than the figure given by
Dickinson, we have 1,932,902,400 tons.
As the whole of the white salt has been manufactured from brine derived
from the rock-salt, it represents so many tons of rock-salt pumped
up. Now, as the specific gravity of rock-salt is 2·125, a cubic yard
contains 32 cwts. This being the case, we find the cubic yards of
rock-salt pumped up annually in each district to be, viz.--
In WINSFORD DISTRICT--
687,000 × 20 / 32 = 429,375 cubic yds.
In NORTHWICH DISTRICT--
587,000 × 20 / 32 = 366,875 cubic yds.
In MIDDLEWICH DISTRICT--
14,000 × 20 / 32 = 8,750 cubic yds.
In SANDBACH DISTRICT--
78,000 × 20 / 32 = 48,750 cubic yds.
Making a total of 853,750 cubic yds. This represents 176·5 acres of 1
yd. thick.
This is entirely independent of the rock-salt, which, at a low
estimate, equals 120,000 tons per annum, or, say, 75,000 cubic yds., or
15·5 acres of 1 yd. thick.
In these calculations no allowance has been made for wastage, and this
is very large. During the year every pan requires picking from six to
twelve times, the stoved oftener than the common. This necessitates the
pan being swept out and an enormous quantity of brine wasted. Besides
this, the pan scale contains a large percentage of salt. Again, in
_drawing_ the salt out of the pans a large quantity of brine is wasted.
Add to this also the leakage in pipes, overflow of cisterns, leakage
through defective pans, etc., and the total of wastage will be very
large. It is scarcely possible to estimate this, but if we calculate 10
per cent. we shall be under the mark. Thus, for waste, we may set down
136,600 tons. This would represent 85,075 cubic yds., or 17·65 acres 1
yd. thick.
We thus see that 209·65 acres of rock-salt 1 yd. thick is every year
consumed in the Cheshire salt district.
CHAPTER VI
THE CHESHIRE SUBSIDENCES
The salt industry of Cheshire may be divided into three periods, viz.:
the natural brine period, the rock-salt period, and the prepared brine
period. From Saxon times up to the last quarter of the seventeenth
century the manufacture of white salt from brine had been continued
without interruption, but the output had never been large. In 1675 the
production of the three “Wiches” was returned at 20,000 tons, and all
the evidence shows that the total annual make had never exceeded 30,000
tons. In 1670, rock-salt was discovered in the county, and for the next
hundred years, although brine continued to be worked, rock-salt mining
was the chief producing industry. With the collapse of the mines, the
salt proprietors turned once more to the brine supply, upon which
Cheshire has since risen to its present commercial eminence as one of
the great salt-making centres of the world.
In 1670, a rock of natural salt was discovered on the Marbury Estate,
about one mile north of Northwich, by one John Jackson, of Halton, who
was engaged at the time in “searching for coals on behalf of the Lord
of the Soil (or Manor, I should say), William Marbury, of Marbury,
Esquire.” The event was communicated to the Royal Society by Mr. Adam
Martindale in a letter dated 12th December, 1670. He added that the
liquid issuing from the rock was “a vigorous sharp brine beyond any
of the springs made use of in our salt works,” and, being asked by
the Royal Society to visit the place and send a further report, he
subsequently wrote: “The rock of salt, by the relation of the workmen,
is between 33 and 34 yards distant from the surface of the earth,
about 30 whereof are already digged and they hope to be at the Flagg
which covers the salt rock about three weeks hence.... That piece of
natural salt which the instrument brought up (divers saw it, a pure
ore) was as hard as alum and as pure.”
The records of the rock-salt mining period are singularly incomplete,
inexact, and disappointing. It is not known for certain which was
the first mine sunk after the discovery of the salt-bed in 1670. It
may have been the one which is described as “very near to a small
brook which drains Marbury Mere and joins the Witton Brook, near the
Buttevant Bridge on the Marbury Estate.” Or it may have been another
early mine which was situated “close to a small runnel or gutter which
runs into this small brook near the Dairy House Farm but passes across
the land of Mr. Lyons and over the old Marston mine.” If the curious
inquirer is not yet satisfied with these conjectures, he is further
informed that there is yet another subsidence of an old mine, “close to
the Forge Lane or road leading to Budworth across the Fields, where the
road branches off at the cottages and salt-works of Mr. Lyons’ property
... and this mine is probably the earliest sunk.”
But if little is known about the beginning of the salt-mining industry
in Cheshire, there is not much more to be learnt about its development
and ultimate decay. To-day, only the Adelaide Marston Mine at Northwich
is working, and of the nineteen mines that were open in Cheshire in
1881, only nine were at work, while from an undated plan and key
showing the rock-salt mines in the Northwich district, which was
probably published a few years earlier, we learn that of the fifty
rock-salt mines that had been abandoned, twelve had been sunk to the
bottom bed and the rest had been worked as top-bed mines.
[Illustration: INTERIOR PENNY’S LANE MINE, NORTHWICH]
The story of the exploitation of the top and bottom beds is one that
is soon told. The top bed was worked until the mines began to fall
in and the subsequent breaking in of fresh water converted the old
workings into brine reservoirs. In 1779, the discovery of the lower
bed of rock-salt at Lawton prompted the owners of the Marston Mine at
Northwich to sink below the top bed in which they were working, and,
in 1781, a trial shaft which was sunk from the top mine by means of a
horse gin, demonstrated the existence of the bottom deposit in that
district. Other owners transferred their operations from the top to the
bottom bed, and for the next fifty years practically all the rock-salt
was excavated from that source. In 1830 the roofs in these workings
began to crack, and attention was directed to the insufficiency of the
pillars by which they were supported. A competent surveyor, who did not
hesitate to declare that the workings were in a dangerously insecure
condition, was regarded as an alarmist by the old salt proprietors, who
commissioned other “experts” to examine the pits, and were satisfied
with their assurance that they considered each pit to be entirely free
from any danger, and that they should not hesitate to work in any of
them. Three years later the roof of the first bottom-bed mine fell in,
others collapsed in rapid succession, and by 1840 some twenty mines had
collapsed, let in water, and become filled with brine. In 1881, only
nine rock-salt mines were at work, and eight of these had a combined
area of 123 acres.
Rock-salt mining in England is a dead industry, but it will be of
interest to outline very briefly the methods that were employed in
Cheshire during the comparatively short period of its existence. The
old top-bed mines were operated, in the first place, with one shaft
to each mine, and they were ventilated by means of an air-pipe and a
fan. A horse gin was used for winding, but the winding-shaft in which
the gin rope worked did not go into the rock-salt, but only to within a
short distance of it, and it was out of this shaft, at a distance of 2
or 3 yds. from the bottom, that a side drift was driven. From this side
drift a windlass pit was sunk into the rock-salt, and it was up this
windlass pit that the rock-salt was drawn to the drift and thence taken
to and up the gin shaft, the part of the gin shaft below the drift
being used as a sump or lodgment for water. These top-bed workings
did not usually extend more than 100 yds. from the shaft, but, as the
number of the mines increased, the workings from adjoining shafts
occasionally become connected. In this way one shaft became a downcast
and the other an upcast, and the air-pipe and fan at each were able
to be dispensed with. The thickness of rock-salt worked averaged from
30 to 36 ft., and pillars of natural rock-salt, usually about 5 yds.
square, were left to support the roof and superincumbent strata.
Although the bottom-bed mines were worked upon the same plan, the
inadequacy of the supports employed in the top-mines was rectified by
an increase in the size of the supporting pillars and in the thickness
of the rock-salt roof that was left between them. Steam engines with
direct shafts to the bottoms of the mines were substituted for the
horse-gins and windlasses, and improved methods were introduced for
preventing water from breaking into the shafts. Two winding-shafts
were sunk, placed about 10 to 15 yds. apart, and a pump-shaft was
sunk to the depth to which the surface water penetrated. One of the
earliest precautions taken in the rock-salt shafts, and afterwards
in brine shafts when they came to be sunk through rock-salt, was to
protect the sides from the ravages of fresh water. All the shafts were
roofed over to keep out rain or snow, and the wood casing, which was
originally used, was replaced, in 1845, by cast-iron tubings, similar
in construction to those used in colliery shafts.
As soon as the miners had sunk the shaft to the depth of the sole
or floor of the mine and had made an opening large enough for their
purpose, they proceeded to blast off enough rock to form a chamber
about 5 ft. high. This formed, they advanced by blasting off the
rock-salt from the face of the seam. The salt was loaded into waggons,
which ran along small railways to the mouth of the shaft. The men
engaged in blasting the rock and squaring the walls and pillars (for
these were left quite square and well hewn) were called _miners_; those
who loaded the trucks and conveyed them to the shaft were _ferriers_.
They were a fine set of men, and their occupation, compared with
coal-mining, was a very healthy one. The mines were of an equable
temperature, and were sufficiently warm for the men to dispense with
their shirts. Being lofty, the air was pure, except when excessive
blasting was undertaken. The greatest number of men employed in one
pair of shafts was about eighty, and the quantity of blasting powder
used by that number in the course of a day averaged 1 cwt. Safety fuses
were seldom used, the charge being fired by a straw filled with fine
powder, which was lighted from a candle.
Many of the mines were of considerable size, and some of them increased
at the rate of about an acre annually. The quantity of rock-salt mined
was small compared with coal. No mine in the district yielded above
40,000 tons per annum.
Rock-salt is more free from danger than most kinds of mining; no
explosions occur, for there are no deleterious gases, and accidents are
rare. In a general way the rock-salt strata are remarkably free from
carbonic acid gas, and in only one instance in Northwich, and twice at
Meadow Bank, Winsford, does fire-damp appear to have been met with, and
then only at pipe veins and in very small quantity. There are no falls
of earth, as in coal mines, for the rock-salt is extremely tenacious,
and the miners never undermine it but blast it, which is a much safer
operation. The two great dangers to which rock-salt mining is exposed,
though they rarely result in loss to human life, are the falling in
of the mine bodily, or of the shafts and neighbouring earths, and the
breaking in of brine either at the head of the top-rock shaft or from
old mines, long disused, and full of brine.
Neither the name of the first mine that fell in, nor the date of its
collapse, is recorded. We know that a mine in Witton fell in in 1750,
and another to the north of the Northwich Town Bridge followed in 1759,
and that many others collapsed before 1770. Lakes, or “flashes” as they
are called locally, have formed over the larger of these sinkings,
but the sites are more commonly marked by what are known as rock-pit
holes, and large tracts of country are scored with these funnel-shaped
indentations. There can be no doubt that a number of these old mines
were worked with pillars that were too few and slender for the purpose,
and these supports gradually weakened to their ultimate collapse under
the pressure of the superincumbent earths. As the sinking did not take
place evenly all over the mine, but most frequently occurred near the
shafts and at the greatest distance from the sides of the cavity, the
roof would curve down towards the sinking centre and the falling-in
formed the V-shaped apertures on the surface which are described as
rock-pit holes. But, while in a percentage of cases the collapse of the
mine could be traced to the crashing of the pillars, the destruction
of the majority of the mines was caused directly by the influx of
water, although this water, having become saturated with salt, would,
if undisturbed, cause no further havoc in the interior of the mine.
But the manufacture of white salt from brine, which was temporarily
surpassed in importance by the rock-salt industry, was not
discontinued, and a copious supply of brine flowing over the rock head
of the upper bed, was tapped by shafts and pumped to the surface.
When, about 1850, this supply showed signs of failing, attention was
directed to the enormous reservoirs of brine in the old inundated
mines, into which had drained a great quantity of the rock-head brine.
The attempt to pump brine out of the abandoned workings was successful,
and for some years an abundant supply was obtained. After 1870 the
pumping operations caused further collapses, the land overlying the
mines subsided, and lakes were formed which, at intervals, broke into
the partially exhausted reservoirs, and, pouring through the top-rock
workings into the mines in the bottom bed of salt, replenished the
supply of brine. A great collapse which occurred in the Dunkirk
district in 1880 let down the waters of Cranage Brook and the
Wadebrook, together with a huge quantity from the river Weaver. The
subsidence resulted in the formation of a large lake, which, following
upon a later subsidence in the same area, suddenly disappeared into the
earth and literally flooded all the underlying strata.
Surprise has frequently been expressed that in a salt country in which
brine has been manufactured for over twenty centuries, the existence
of the rock-salt deposits should only have been discovered in the last
two hundred and fifty years, but it must be borne in mind that not
only was the brine the best custodian of the secret of its own source,
but that, when the problem of the supply had been solved, the danger of
tapping and controlling it had still to be overcome. When the supply
of brine in many of the springs was cut into, it proved so copious
that the sinkers had to flee for their lives and to ascend the shaft
among the brine. The fact that the depth at which the brine would be
encountered was unknown, explained the inability to provide a safeguard
against the sudden inrush of brine, but subsequent observation showed
that when the workmen met with the “flag,” or bed of hard marlstone
that existed above the top of the rock-salt in many districts, the
brine might be expected to be found at high pressure. It was then
the practice to case the shaft sides down to the flag to prevent the
entrance of surface water, and either to blow through the flag with
powder or pierce it with boring rods. At a later period, the shaft was
sunk to the approximate point of encounter with the brine, and cased
with iron cylinders, the bottom cylinder being furnished with an iron
bottom pierced with two pipe holes. A column of pipes was erected in
the cylinder, and a set of boring rods was let down each pipe, so that
when the flag was bored through, the brine rose until it attained its
level in the pipes, while by means of a tap attached to each pipe it
was possible to stop the entry of the brine and to empty the shaft.
In the brine-shafts employed in the case of the old rock-salt mines,
in which the brine was met with at a much higher pressure than in
the rock-head brine-shafts, the tapping operation was attended with
extraordinary difficulties. The brine in the old workings rose to a
height corresponding with that attained by the brine found at the
rock-head, and as it had to be tapped through a pillar near the bottom
of the old workings, the pressure was proportionately higher. When
the holeing was first effected into the brine in the old bottom-bed
workings, the rush of the incoming brine was so strong that it passed
through the two 5 in. bore holes and rose up a 4½ ft. shaft to a height
of 67 yds. in eight minutes. The shaft for tapping this supply of brine
was sunk in a pillar of rock-salt, and a drift, fitted with two 5 in.
bore-holes, was worked through the intervening face and into the brine.
When these bore-holes were knocked through, the brine entered with the
report of a cannon, and the engineer and his assistant, leaving their
tools behind them, leapt into the bucket and were hastily drawn up the
shaft, closely pursued by the rising brine.
An improved process for tapping the brine, which entirely removed the
danger attending the operation, was subsequently introduced. This
was effected by boring the last part of the main bore-hole through a
stuffing-box at the other end--an innovation which prevented brine from
escaping during the boring. A drift, with the usual ⅝ in. bore-hole
in advance, was driven 61 yds. into the barrier, until the small
bore-hole showed that only 10 yds. remained between the face and the
brine that was known to be present in the old workings. Into this
remaining 10 yds. of barrier a hole 11 in. in diameter was bored until
nearly through, and a closely-fitted pipe was inserted into the hole
for a distance of 7 ft. The pipe was 10 ft. long, but at 7 ft. from the
inner end was a disc 3 ft. in diameter to rest against the face of the
drift, leaving the remaining 3 ft. of pipe in the drift. About midway
between the disc and the outer end of the pipe, were placed two strong
iron uprights, let into a trench cut 1 ft. deep in solid rock-salt in
the roof and floor to secure the pipe against the pressure. These two
uprights were placed close together at the top and bottom, but in the
middle they were curved so as to form a circle for the pipe to pass
between them. The face of the drift against which the disc had to rest,
having been carefully dressed, and a disc of india-rubber covered with
red lead having been placed between the iron disc and the dressed face
of rock-salt, the iron disc was secured up tight against the face by
means of six set screws. A stop-valve was then fitted to the outer end
of the pipe, and to this, for the temporary purpose only of completing
the bore-hole, was attached an end piece with a stuffing box and a hole
in it large enough for the bore rod to be worked through. The bore rock
was then withdrawn and, the valve being closed, the stuffing box and
the temporary end piece were removed. A range of pipes was attached to
the stop-valve and, in this range, the brine was taken through the old
workings and up one of the shafts to the surface.
Many geologists have subscribed to the theory that the Cheshire
meres were formed by subsidences which occurred in pre-historic
times, but the evidence based on the phenomena attending the modern
subsidences proves that the latter were the result of artificial and
readily-identified causes. Leland, in 1533, reports a sinking near
Combermere and the formation of a pit containing salt-water; in 1657 a
small sinking occurred at Bickley, near Malpas; and a third took place
in 1713 at Weaver Hall, to the south of Winsford. No traces of any of
these subsidences now remain, but, from the descriptions handed down
to us, these sinkings belonged to the class of funnel-shaped holes and
were of limited diameter and no great depth.
Of the modern subsidences, which are of three kinds, we have no
documentary evidence prior to 1777, and the earliest distinct record
belongs to the year 1790. From that time to the present day this class
of sinking has continued to increase in extent year by year. In 1790
the sinking portion along the Witton Brook was recorded as being 130
yds. long by 90 yds. wide. In 1837, the subsidence had obtained an area
of 1,230 yds. long by 130 yds. wide. In 1811, about 20 statute acres
in Witton commenced sinking, and in the ensuing thirty-three years
some portions of this area had sunk 24 ft. In 1880, the piece of water
called the Top of the Brook had subsided over an area of 4,370 ft. by
1,470 ft., and in the same year it was estimated that no less than
2,700 acres of land in Northwich and Winsford were inundated.
These modern subsidences usually consist of funnel-shaped holes caused
by the falling-in of top-rock mines, and of trough-shaped hollows
which cannot be connected with rock-salt mining, and are frequently
found in places far removed from the localities of the old workings.
Of two dozen subsidences, two are nearly four miles distant from the
nearest old workings or from the brine shafts, fifteen are upwards of
two miles, and only one is less than a mile from either a mine or a
pumping station. The subsidences could not be caused by volcanic action
or the shock of earthquakes, as nothing of the kind has occurred in
the districts, and it is impossible to explain them by the action of
natural brine springs running to waste in the brooks or rivers, because
it is known that no such springs now exist, while evidence accumulated
from all parts of the world confirms the conclusion that where brine
springs escape into the streams, no subsidence has ever occurred.
Yet it is evident in Cheshire that some subterranean denudation must
be taking place which is removing portions of the lower strata and
allowing the super-incumbent earths to sink into the excavations
thus made. Many theories have been advanced to explain the phenomena,
but even those people whose interests have caused them to seek for
alternative causes must realize that it can only be attributed to the
simple and most obvious agency.
When the number of brine pits was multiplied and the natural springs
of a weak solution of salt decreased in volume, it was necessary to
sink down to the rock-head brine, which was a highly-saturated solution
consisting of one part salt to three parts water. When this supply is
pumped up, its place is taken by fresh water, which, flowing over the
rock-beds, takes up its quota of salt on its way to the pumping shafts,
and is raised to the surface in the form of brine.
It is not the presence of water over the beds of salt or in the old
salt workings which causes the damage, because when such water has
taken up salt to the extent of a fourth of its bulk, it remains
inactive and makes no further ravages upon the mineral earths with
which it is in contact. But when the saturated brine is pumped up
and its place is taken with a new supply of water which collects its
tribute from the salt strata, and that water, in its turn, is raised,
to be replaced by more, and when it is known that each 100 tons of
water that traverses the salt-bed to the pumps carries away with it 25
tons of solid earth, the work of destruction that is continually going
on is explained.
It may be convenient to explain at this point that the subsidences
caused by this simple operation of removing rock-salt from the earth in
the form of brine are divided into three classes, viz.--
1. Shallow troughs, with sides not terraced or broken up.
2. Very shallow depressions extending over considerable areas.
3. Deep troughs, much broken up, and with stepped or terraced sides.
With these three classes in mind, it is easy to follow the results of
the action of the subterranean brine and associate the causes with the
effects produced. At first the water flowed over the salt in irregular
channels and reached the pumping centres by devious routes, but after a
time it made defined courses for itself exactly as the rainfall carves
out for itself channels on the surface of the earth. These underground
streams of brine all gravitate towards the pumps, widening and
deepening as the continually renewed water takes up its supply of salt.
Where the earths overlying these brine “runs” are not too tenacious,
they soon follow the hollow or trough formed on the surface of the salt
bed, and a corresponding hollow or trough is formed on the surface
of the ground. Where the hollow forms at an early stage, it rarely
attains any considerable depth, for the sinking earths impede the
course of the flowing brine stream and cause the fluid to spread and be
diffused over a wider area. These subsidences are the shallow troughs,
not stepped or terraced on the sides, and are best seen in streets
and roads where the weight of the houses and the constant passage of
traffic cause the earths to gradually follow the wasting surface of
the salt. Where, at a considerable distance from the shafts, the water
has not formed for itself a definite channel, it percolates over a
wide area. The denudation in such cases is more generally spread, and
a very extensive shallow trough or basin is formed. Again, where the
pumping stations are close together, or in the same line, the various
rivulets or streams of brine converge into one broad and deep channel,
in which the denudation proceeds with great rapidity. The magnitude of
these channels causes the super-incumbent ground to subside swiftly,
forming deep troughs with stepped or terraced sides, where the earths
have broken away in huge masses. Where the earth consists of strong
marls and a kind of flagstone they are very tenacious and remain
suspended for a considerable time over these deeper cavities. When
they will bear no longer, a sudden fall occurs in one spot, and tens
of thousands of tons of suspended earths fall into the trough below,
forcing out the stream of brine at the weaker places and leaving a
huge, crater-shaped hole on the surface, which fills with water.
[Illustration: REMARKABLE SUBSIDENCE IN NORTHWICH]
In addition to the three classes of subsidences already mentioned,
there is another which is the result of a combination of collapses of
the surface earth caused by the rock-salt mining operations, and the
denudation of subterranean strata caused by the pumping of brine. The
pumping from the reservoirs formed by the flooding of the old mines
does not empty these huge receptacles, as the place of the brine
is continuously retaken by fresh water, which naturally gravitates
to these centres and proceeds to dissolve and take up its quota of
rock-salt. When a subsidence occurs on the site of these old workings
it is of the most destructive nature, and as all the top-rock mines
were in the neighbourhood of streams and brooks, the surface waters
flow into the cavity until it is filled to the level of the earth
and allows the streams to pursue their proper course. But as fast as
the fresh water becomes saturated and is pumped to the surface, the
overlying stream or brook lets in further supplies of fresh water to
fill the vacuum, and the work of internal destruction is followed by
further subsidences of the suspended earths.
The immense bodies of water in the neighbourhood of Northwich and
Winsford, locally called “Flashes,” which cover a total area of many
hundreds of acres, are the work of subsidences. The Flashes are not
shallow swamps, but lakes varying in depth over many acres, from a few
yards to 50 ft. The largest Flash, known as the Top of the Brook and
resembling the letter =L= in shape, has a length in each arm of about
half a mile, an average breadth of a quarter of a mile, and attains a
depth of 150 ft. In an account of these subsidences, written in 1879,
we read: “The whole of the surrounding district still sinks rapidly,
and year by year the water covers more ground. The land subsides
gradually here; but when we go a quarter of a mile to the north-east
of the Top of the Brook, we come across a subsidence of a still more
alarming character. Here the ground sinks bodily in immense masses to
a great depth. A tiny brook or ditch that a child could skip across
passed over flat fields some five years ago. Gradually the land began
to sink, and cracks opened in the surface right across the course of
the brook. The water went down the crevices. The land immediately sank
more rapidly; huge cracks, wide enough for a man to slip down, formed,
and very soon a district extending fully one thousand feet in length
by as many in breadth, sank rapidly to a depth of forty or fifty feet
in the centre, and was filled up to a certain height with water, which
covered the hedges and trees. At times cracks opened in the bottom of
this lake, and the whole of the water rushing rapidly below, caused
still more extensive sinking.”
One of the most extraordinary subsidences, which was described in
_Chambers’s Journal_, occurred in Dunkirk, on the outskirts of
Northwich, in December, 1880. The earliest intimation of impending
disturbance on an unusual scale was a rumbling subterranean noise, the
violent bubbling of the water in all the surrounding pools, and the
uprushing of air and foul gas through rifts which its passage tore in
the ground. It was quickly discovered that Wincham Brook, a channel of
water nearly 20 ft. in width, had broken into the earth about 1,000
ft. from its entrance into the Top of the Brook, and the uprush of air
from the old mines, was caused by the force of the descending waters. A
series of alarming, but comparatively small, subterranean displacements
caused extensive rifts in the ground about Ashton Salt-works, and these
were followed by a sudden explosion in a neighbouring pool, which
ejected a geyser of mud and water some 30 ft. into the air. In the ruin
that ensued, stacks of timber, an engine and boiler, a salt pan, and
other material disappeared into the gaping earth, and a massive chimney
stack, some 90 ft. high and 9 ft. square at the base, tilted towards
the centre of subsidence and collapsed with a terrible crash. Scarcely
had this subsidence ceased, says the writer in _Chambers’s Journal_,
“when an enormous sinking of the whole of Ashton’s Old Rock Pit Hole
and the surrounding land, for an area of over five hundred feet in
diameter, took place, leaving two very deep holes. The land was riven
and cracked all round, and fell in steps of two feet. Over ten thousand
tons of water went down into the subterranean cavities. A huge brine
cistern was riven in two, and the brine all lost; and two large brick
kilns cut completely in halves, and the bricks scattered about. The
whole surface of the Weaver and the Top of the Brook was lowered fully
a foot over one hundred and sixty acres in about four hours; and if
we add to this the whole of the water of the Wincham Brook for twelve
hours, we shall find, on a careful computation, that not less than six
hundred thousand tons of water rushed below.”
From the time of the “Great Subsidence,” as this event is described,
the sinking has been continuous throughout the locality. In some places
meadows have been converted into swamps, roads have sunk fully 30 ft.
below their original level, and small brooks have become lakes of
many acres in extent; sunken and distorted fences, roads, and streams
are common objects of the country-side, the tenure of pastoral lands
is precarious, and property is valueless for building purposes; and
nothing but its inexhaustible reserves of brine saves the district from
abandonment as a place accursed.
The shallow, gradual, almost imperceptible subsidences which occurred
in the neighbourhood of the towns of Northwich and Winsford were at
first infrequent and of comparative unimportance, but as time went
on the damage to property increased so rapidly that, in 1860, the
house-owners of Northwich combined in an unsuccessful attempt to obtain
legal redress. By 1880, many parts of the towns were rendered unfit for
habitation. In Northwich alone, nearly 400 houses and other property
to the value of over £100,000 were more or less seriously affected,
while water-mains, sewers, and gas-pipes were being continually
repaired; houses were condemned, pulled down and rebuilt, and bridges
had to be raised. The rents of many lots of property were absorbed in
keeping them in repair, and in some districts property had been raised
and rebuilt three times in eleven years. “The area of the mischief
is extending yearly,” wrote Mr. Thomas Ward in 1881, “and a larger
proportion of property is becoming affected, and more and more land
is sinking beneath the water and increasing the area of the already
existing extensive lakes. Very few, except those conversant with the
district, have the slightest knowledge of the amount of suffering
caused to property owners by this subsiding of the land.”
For over half a century the appearance of Northwich, with its
undulating streets, its ramshackle, dilapidated houses, its fissured
walls, and its system of shoring and bolting-up of property to postpone
as long as possible its inevitable condemnation and demolition, has
presented a tragico-comic spectacle. “If a stranger were to be set down
some morning in the town of Northwich,” wrote a _Times_ correspondent,
“without any previous knowledge of its peculiarities, he would be
struck with a startling and novel spectacle. He would see buildings of
every sort, from the humble, two-storeyed cottage of the artisan to
the solidly built church or chapel, standing many degrees out of the
perpendicular, and suggestive, all of them, were it not for the props
and iron stays with which they are secured, of some recent convulsion
of nature. In main thoroughfares and back streets alike there are
houses whose sloping floors and cracked walls would lend considerable
colour to such an effort of the imagination. The inhabitants seem to
take this tumble-down state of their dwellings quite as a matter of
course. They have, in fact, to make the best of a condition of things
from which there is absolutely no escape. The effects described are
produced, not indeed by any sudden catastrophe, but by a slow, though
equally effective process of subsidence, which may be detected in
continuous operation over nearly the whole area of the Cheshire salt
field, and which will continue to operate so long as the earth yields
its vast stores of salt for human consumption.”
But although newspaper representatives could philosophize upon the
matter-of-fact spirit in which the inhabitants of the salt towns
faced existence in their tumble-down surroundings, and the salt
proprietors desired that they should make the best of a condition of
things from which they wished them to believe there was absolutely no
amelioration or escape, a feeling of resentment was rapidly growing
in the neighbourhood. The people of Northwich and Winsford were being
pumped out of their houses and out of their lands, and the future
held every promise of a continuation and extension of the damage.
Lord Delamere, who, as an owner and letter of salt lands, benefited
by the brine industry and suffered from the depredation it wrought,
admitted the damage and the cause thereof. Indeed, nobody but the salt
proprietors doubted that the pumpers were wholly responsible for the
destruction, and most people recognized that their wrong-doing was
twofold in character. Standing on the ancient assumption in law that
everything beneath a man’s property belongs to the owner, the owners
of property in the affected districts contended that they were not
only being deprived of the rock-salt which legally belonged to them,
but were further despoiled by having their land made worthless by the
abstraction of the salt for which they received no payment. The justice
of the protest was obvious, and it became a public question how far
these operations, useful in themselves, but involving consequences of a
disastrous nature, should be allowed to proceed. In December, 1880, the
_Daily News_ asked who was to compensate the sufferers, who had neither
caused nor contributed to the disaster.
Following the failure of the property owners to obtain compensation
from the salt proprietors for the damage attributable to the pumping
operations, an application was made to the Trustees of the River Weaver
to devote a portion of their surplus revenue for compensation purposes.
The application was refused, and an appeal to Quarter Sessions failed.
The evil was allowed to drag on until 1871, when the Board of Trade,
in response to representations made to them by the Northwich Salt
Chamber of Commerce, instructed Mr. Joseph Dickinson to report upon
the salt districts of Cheshire. Mr. Dickinson, one of the most eminent
Inspectors of Mines in the service of the Government, after a prolonged
investigation, reported his conclusions that the subsidences and the
resulting damages to property were caused by the pumping of brine,
which constituted a public danger and inflicted heavy losses upon
many persons totally unconnected with the salt industry. A further
report by Colonel Cox, corroborating the conclusions arrived at by Mr.
Dickinson, came before Parliament in 1879, and upon the recommendation
of the Local Government Board, the local Boards decided to promote
the Cheshire Salt Districts Compensation Bill, “to make provision for
the assessment, levy, and application for compensation for damage by
subsidence of land in the salt districts of the County of Cheshire, and
for other purposes.”
The salt proprietors exerted every effort to frustrate the plans of the
promoters of the Bill; they declared that a tax upon salt would cripple
the trade and ruin the entire neighbourhood; they endeavoured to create
local ill-feeling by insisting that the movement was an attempt of
the property-owners to saddle the ratepayers with the expense of the
proposed measure. Briefly stated, the case that the promoters were
asked to make required them to prove (_a_) the subsidence in the salt
district; (_b_) that the subsidence was caused by the pumping of brine
for the manufacture of salt; (_c_) that the subsidence was of a most
extensive and serious character, and affected the property of persons
deriving no benefit either from the manufacture of salt in the form of
compensation from the salt manufacturers for the salt extracted, or for
damage done to the property by such abstraction; (_d_) that there was
no legal remedy for the injury suffered; and, finally, (_e_) that the
moneys required to adequately compensate for the injury done, if levied
upon the manufacture of salt, would not injuriously affect the salt
industry.
[Illustration: A ROW OF OPEN PANS]
A copy of the Bill was lodged in December, 1880; it was read a first
and second time on 21st January and 4th February, 1881, and referred to
a Select Committee, which commenced sitting on 5th May, and on the 20th
of the same month announced their unanimous opinion that the preamble
of the Bill had not been proved. In the preamble of the Bill it was
estimated that a contribution not exceeding threepence for every ton of
salt in brine in the district covered by the Act would be sufficient to
provide the required compensation. The opponents of the Bill declared
that a compensation tax upon the salt trade would severely injure the
industry and act as a restraint upon trade; they put forward expert
witnesses to contend that if the brine--which they contended was
produced by rainfall percolating through the superincumbent strata and
reaching the salt--was not pumped out, it would run away to the sea,
and the consequent subsidence of land and injury to property would
not be arrested. The theory that brine, in quantity sufficient for
the manufacture of 1,600,000 tons of salt per annum would, without
pumping, have been carried away into the rivers by natural agency and
deposited in the sea, was supported by such ingenious misstatement
and misrepresentation, and the fictitious instances of brine springs
overflowing and causing damage in other parts of the world were quoted
with so much specious authority that they succeeded in wrecking the
Bill.
After a further ten years of continued subsidences and attendant damage
to public and private property, the Brine Pumping (Compensation for
Subsidence) Bill was introduced in 1891, to authorize the formation of
Compensation Districts and Boards, with power to levy a yearly rate not
exceeding threepence per 1,000 gallons of brine pumped. Shortly after
the passing of the Bill, the action of Northwich, which memorialized
for the formation of the whole of the County of Cheshire into one
district for purposes of compensation, led to an inquiry by the Local
Government Board, as the result of which Middlewich and Sandbach were
excluded. The Provisional Order uniting Northwich and Winsford in one
area was opposed by Winsford, and a Select Committee of the House, in
1893, quashed the Provisional Order and made Northwich an independent
compensation district.
The next great struggle in the salt district, known locally as the
Battle of the Brine, arose out of the action of the Salt Union, which,
in 1909, enlarged its works at Weston Point with the intention of
manufacturing salt at that place from brine pumped at Marston, near
Northwich, 11 miles distant. In pursuance of their policy of stalling
off competition and safeguarding their monopoly, the Salt Union, in
1890, had successfully petitioned against the Bill that was promoted
to obtain powers to convey brine from Cheshire to be made into salt
at Widnes, in Lancashire, and at Middlewich they had obtained an
injunction to restrain trade competitors from laying pipes under one
of the streets of the town for the conveyance of brine from their
own pumps to their own salt-pans. In 1766, 1833, and 1861, the Trent
and Mersey Canal, the Grand Junction Railway, and the West Cheshire
Railway, respectively, received authorizations from Parliament, but in
each instance a clause was inserted prohibiting the several companies
from conveying or permitting to be conveyed in or upon any part of
their properties, any brine for the making of salt to any district
beyond the district in which salt was then made. In 1884, when the
London and North-Western Railway sought to gain the repeal of the brine
clause in order to enable brine to be carried from one salt township to
another adjoining, Parliament refused to sanction even such a limited
modification of the prohibition. The logical objection which the salt
districts opposed to the removal from the several pumping centres of
the brine upon which the prosperity of the towns entirely depended, had
thus consistently been upheld by Parliament, but in the face of these
facts, and of their previous attitude on the subject, the Salt Union
insisted upon their right to carry brine from Marston to Weston Point,
and announced their intention to defend their position to the utmost of
their power.
It must be explained that the Marbury Pipe Line had been laid in 1882
by the Mersey Salt & Brine Company, who carried it, by agreement,
across lands belonging to private landowners and over a canal belonging
to the North Stafford Railway. The railway made a formal protest, but
an amicable settlement was ultimately reached by which the Mersey
Salt Company agreed to pay the North Stafford Company £5 a year and
to remove the pipe on receipt of a three months’ notice. The railway
company appear to have persisted with their opposition in order to
force an admission from the Mersey Company that they possessed no
permanent right to carry the pipe across their canal, but the concern
was of such trifling importance that it was practically ignored by the
people of the district, and for twenty years after the property of
the Mersey Salt Company and the Marbury Brine Pipe had been acquired
by the Salt Union, the question of the removal of brine from the
neighbourhood in which it was raised had found all classes of the
salt community united against such proposals. But with the completion
of the works at Weston Point, and the enlargement of the Marbury
Pipe and the installation of powerful engines, capable of driving
millions of gallons of brine from Marbury to be converted into salt
at the sea-board, a new menace was organized against which the Urban
Authorities and Local Councils made a long and spirited, if fruitless,
resistance.
In the autumn of 1910, the North Stafford Railway served the Salt Union
with a notice to remove their pipe line from the Trent and Mersey Canal
by the end of the following March, and the Salt Union proving obdurate,
the towns of Northwich, Winsford, and Middlewich promoted the Brine
Pumping (Cheshire) Bill, “to regulate the conveyance of brine pumped,
raised and gotten” in the county. The original draft, which proposed
to permit the removal of brine by pipe to a distance of three miles
within the county from the place at which it was raised, was amended
to permit manufacturers to carry brine by pipe from one set of works
to another in their own occupation, and they further attempted to meet
the alleged rights of the Salt Union by the insertion of a clause
allowing the Marbury Pipe to be used for the conveyance of brine to
the extent of 250 million gallons a year. But the Salt Union declined
all conciliatory overtures, and combated the Bill before the Select
Committee on the grounds that it was a proposal to alter the common
law of England and interfere with the sacred rights of property. The
injury that was sought to be done, not only to the Salt Union but to
the export trade of the country, was enlarged upon, and the Committee
may have been impressed by the assurance that the Union, so far from
intending to leave Winsford and Northwich, expected to do an even
greater trade in those districts in the future than had been done
there in the past. In the result, the Salt Union’s insistence upon the
legality of a course of action which they had previously denounced and
opposed as totally illegal, carried so much weight with the Select
Committee, that they made an unsavoury meal of the Parliamentary
decisions of 1766, 1833, 1861, 1890, 1891, and 1893, and announced that
the Bill could not proceed.
CHAPTER VII
LATEST METHODS OF SALT-MAKING
In tracing the development of the salt-making industry in this country,
it will be observed that, until the last quarter of a century, the old
open-pan system defied improvement, and the salt-makers from generation
to generation successfully resisted the endeavours of all who suggested
innovations or hinted that better methods could be introduced in the
manufacture. It is true that experiments were made with the sizes and
arrangement of the pans, that coal replaced wood and straw as fuel,
that the locomotive superseded the wain as a means of transporting salt
from the works to the markets, and that pumps were employed instead
of buckets to raise the brine and deposit it in the cisterns which
supplied the pans; but these several developments produced no change
in the system of manufacture, which consisted of lighting a fire
beneath a pan of brine, driving off the water in the form of vapour,
and collecting the salt crystals that form and sink to the bottom of
the pan. The salt-men were devoted to their primitive, rule-of-thumb
methods, and the most enterprising among them regarded the process as
unimprovable. In the construction of salt-works there was no attempt at
engineering exactness; the size of the pans was regulated roughly by
the dimensions of the plates of which they were made; and the heights
of the brickwork of the furnaces, etc., was usually reckoned by courses
of bricks.
The fireman, the real salt-maker, whose business it was to attend to
the fires and see that the proper degree of heat was maintained to
produce the variety of salt required, did his work almost entirely
by rule-of-thumb. It was only rarely that a thermometer was used. The
technical knowledge acquired by experience enabled a man to see at
a glance whether the pan was working properly, and the quantity and
quality of the salt showed whether his work had been well or ill done.
The late Thomas Ward was a greatly respected authority, one of the
most reliable experts of the Salt Union, and a voluminous writer and
indefatigable lecturer on every aspect of the subject of salt, but he
failed to persuade himself that it was even thinkable that the open-pan
system should ever be abandoned in favour of a more scientific, more
rapid, or more economical process.
Mr. Ward admitted that the process was archaic, but he was at pains to
demonstrate that the trade was justified in desiring it to remain so.
He argued that the price of salt was so low, and the product was so
bulky, that costly and elaborate apparatus was both inappropriate and
ineffective. He compared the life of an ordinary open salt-pan with
that of any of the innumerable patented pans that had been tried, and
found that the ancient article produced salt at less cost than the
patent contraptions, and was far easier to repair. “The chief business
of the salt manufacturer,” Mr. Ward wrote in 1894, “is to utilize to
the best purpose, for the production of salt, the heat obtained from
the fuel. To this end, innumerable patents have been taken out, but
few have been so successful as the simple application of direct heat
to open pans. The method seems a very primitive one, and most visitors
to salt-works think they can improve upon what they consider a rude,
antiquated system. I have had brought before me, and have seen working,
scores of patented plans. In all, or nearly all, the idea was to
economize heat; and if the whole of salt manufacturing consisted in
evaporating the greatest quantity of water with the least quantity of
fuel, doubtless many of the schemes would succeed instead of fail, as
they do now.”
Since the open-pan system of manufacturing salt from brine was in
general and uninterrupted use in this country from the time of
Julius Caesar to within a few years ago, we must study the interim
developments from direct-fire to vacuum pan evaporation in the industry
of the State of New York. The salt springs in New York State were
discovered by Jesuit missionaries about the middle of the seventeenth
century, but the manufacture of salt on a commercial scale was not
begun until 1788, when the industry was established in the vicinity
of Syracuse. Solar salt is still manufactured in large quantities
at Syracuse, where the evaporating surface covers an area of over
12,000,000 square feet, and the season’s output amounts to about
3,500,000 bushels of salt, but between the solar and the vacuum
processes the American salt-men have exploited the Pan and the Kettle
processes of direct-fire evaporation, and the Steam Kettle and the
Grainger processes of steam evaporation; all of which methods are
employed to-day in the State of New York.
In the Pan process, several pans, having a width of 20 to 24 ft., a
length of 100 ft. in two sections, and a depth of 12 in., are placed
under one roof. Adjoining this front row of pans at the back are
arranged a second row of pans, 20 to 24 ft. wide, 30 ft. long, and
12 in. deep, set from 12 to 16 in. higher than the front pans, to
enable the easy transfer of brine by syphon from the back to the front
pan. The grates are 3 to 4 ft. wide, by 5 to 6 ft. long, and the pan
bottoms, which are directly over the fires are protected from a too
intense heat by fire-brick arches, which decrease in width from the
front to the back of the pan, while the air spaces between the arches
increase in width in the same direction. Beyond 20 ft. from the front
of the first section of the pan they cease altogether. To convey the
heat as close to the pan bottom as possible, beyond the last arch,
the flues are usually filled in with earth or plaster, and thus the
distance between the pan and flue bottom is between 3 and 4 ft., or
even less, at the end of the first pan, where a perpendicular wall,
called a bridge wall, reduces the space to about 1½ to 2 ft., through
which the products of combustion pass under the back pan and finally
into a common chimney.
After the pans are properly cleansed they are white-washed with a thin
milk of lime to prevent their rusting before they become thoroughly
heated; the fires are started, and the pans are filled by syphons to a
depth of about 6 in. with brine from the back pans. The former are so
inserted that a constant flow of brine passes from the back pans into
the last section of the front pans, and from these under the partition
into the first section. Into the back pan flows a constant stream from
the outside cistern, until the front pans are sufficiently full, when
the flow is stopped. After a sufficient amount of salt has collected
in the first section of the front pan it is removed to the “drip” for
drainage. This is called drawing or raking the pans. The front pans are
refilled from the back pan in which the brine has become considerably
heated, and thus is prevented a too rapid cooling of the brine in the
front pan, which would seriously interfere with the formation of a
properly grained salt. For the same reason, the partition is placed in
the front pan, since it prevents any cold brine from coming suddenly
into the first section, but is compelled to enter at the bottom of the
pan, where the temperature is at the highest.
For the purpose of aiding the formation of fine grained salt, butter,
specially prepared soft soap, gelatine, or white glue are added, and
when this variety of salt is made the pans are drawn every 45 to 60
minutes. In the manufacture of coarser grained salt, the drawing of the
pans take place at intervals of from two to twelve hours, while the
temperature is reduced from 229° F. to as low as 148° F., according to
the size of the grain.
The Kettle process, which is exclusively employed on the Onondaga Salt
Reservation, consists of from 60 to 100 hemispherical cast-iron kettles
suspended or hung on “lugs” or pins in two parallel flues, called
arches, ending in one chimney, which has a height of 50 to 100 ft.,
according to the length of the flues. In front the arches are provided
with cast-iron, flat-topped grates, 3 ft. in width and 5 ft. long,
perforated with holes ⅜ in. in diameter and 1 in. apart. These are well
adapted for the burning of anthracite dust, which is now exclusively
used for the purpose. The necessary artificial draught is furnished by
a pressure blower. The kettles are from 23 to 26 in. in depth, and from
3 ft. 10 in. to 4 ft. 2 in. in diameter, with a capacity of 100 to 150
gallons. The distance from the bottom of the kettle to the top of the
grate is 3 ft. 6 in., with a solid fire-brick arch in each, extending
somewhat beyond the length of the grate. The distance from the bottom
of the kettle to the crown of this arch is 10 to 12 in. Beyond the
grate the fire-brick arches are constructed in sections, the air spaces
between the arches increasing in size with the advancing distance from
the grates. This construction allows the heated gases to pass through
these spaces without striking the kettle bottoms directly. While the
distance between the bottom of the front kettle and the top of the
grate is 3 ft. 6 in., these flues decrease in depth as they advance
towards the chimney, so that under the last kettle the distance is but
6 or 8 in. The kettles are hung as close as possible with their rims
against each other, and the space between the walls and kettles above
the lugs is properly covered by masonry, etc., for the purpose of
confining all the heat as much as possible within the two arches.
The system of kettles is fed by means of a conduit connected with large
wooden cisterns situated outside the building and sufficiently elevated
to supply the brine contained therein by gravity to the kettles in the
block.
The manufacture proper of salt is commenced by lighting the fires under
the kettles and filling them partly with brine as soon as they become
warm, and from within 3 to 4 in. of the top when evaporation has well
commenced. When salt commences to separate, the pan is withdrawn and
the evaporation is allowed to go on undisturbed till a sufficient
amount of salt has separated, when the contents of the kettle are
well stirred with the ladle and dipped into the basket resting on the
so-called basket-sticks laid across the rim of the kettle. While the
process of taking the salt from the kettle is going on, the workman
opens the faucet for a few minutes to add some fresh brine to the
concentrated pickle of the kettle, and washes the salt, so to speak,
with this mixture, thereby freeing it as much as possible from the
adhering calcium sulphate and the calcium and magnesium chlorides.
[Illustration: ILLUSTRATION OF FOUR SCOTT PATENT DOUBLE EFFECT SALT
EVAPORATORS, WITH AUTOMATIC SALT DISCHARGERS, SALT CONVEYERS, AND
HYDRO-EXTRACTORS]
The panning process, though carried out in the best possible manner,
will not completely remove from the kettle all the separated calcium
sulphate, but some of it, together with separated salt, will bake on
the bottom and sides, forming an incrustation constantly increasing
in thickness, though at every refilling of the kettle with fresh
brine much of this adhering salt re-dissolves. This incrustation
increases much more rapidly in the front kettles than in those nearer
to the chimney, since, a front kettle is usually drawn every 4 or 5
hours, while a back kettle often requires from 24 to 36 hours before a
sufficient amount of salt has separated. Moreover, a front kettle holds
150 gallons of brine, while those nearest the chimney contain but 100
gallons. Usually, in 5 or 6 days the incrustation becomes so thick that
it interferes very materially with the evaporation, causing a great
loss of fuel, as gypsum is one of the poorest conductors of heat. The
workman therefore draws the salt from the kettle, removes the remaining
brine to within a few gallons, and refills the kettle with fresh water.
After a continuous boiling of about half an hour, the greater part of
the adhering salt has dissolved and the rest of the incrustation can
easily be removed.
The time a salt block is in operation is between 10 and 15 days, and
the manufactured salt, according to the State laws, remains undisturbed
for 14 days for drainage. A salt block usually cools sufficiently in 24
hours for the kettles, grates, arches, etc., to be properly cleaned and
made ready for the next run, so that about two runs can be accomplished
per month. The quantity of salt produced in 24 hours in a good salt
block, with average good coal dust and brine, is from 500 to 600
bushels of 56 lbs. each, and the amount obtainable by the burning of 1
ton of 2,000 lb. of this fuel varies from 45 to 50 bushels.
There are two salt blocks at the Wyoming Valley, at Warsaw, in which
the Onondaga kettles are heated by steam instead of direct fire. Here,
in place of the brick arches in which the kettles are hung at Syracuse,
they are supported by a framework, and each kettle is surrounded by
a steam jacket covered with a non-conductor. Moreover, the kettle is
made much thinner for the better transmission of the heat. The steam
enters the jacket at the upper end of the kettle at one side, and the
condensed water escapes by a valve below it, to be returned to the
steam boiler. The method of manufacture of the salt does not differ in
any particular from the Onondaga method.
The grainer or Michigan process is, like the “kettle method,” a purely
American invention, and consists in passing live or exhaust steam
through a set of iron pipes immersed in long, shallow wooden or iron
vats. These vats rest on a strong wooden frame. They are from 100 to
150 ft. long, usually 12 ft. wide, and from 20 to 24 in. deep; provided
with four or six steam pipes having a diameter of 4 to 5 in., and hung
on pendants 4 to 6 in. above the bottom of the vats. These pipes are
within a few feet of the same length as the grainer, and so arranged
that the salt can be conveniently removed towards the outer side of the
grainer.
To obtain the best effect in a grainer system, the temperature
of the heated brine is kept at or near the boiling-point when no
lifting or removal of salt is in progress. To do this an abundance
of high-pressure steam must first be supplied to the grainers, and,
secondly, the constant supply of brine required for the grainers while
evaporation is going on, must enter at a temperature but little lower
than that of the brine in the grainer. For this purpose two large
tanks, called settlers, are employed, which are usually as long and
wide as the grainers, but 6 ft. deep, and provided with four rows of
steam pipes about 1 ft. above the floor to heat the cold brine drawn
into them from the outside cisterns as required. Although the six rows
of steam pipes in the grainer have an entire length of from 550 to 750
ft. (suspended in the brine 4 to 6 in. above the bottom of the grainer
and with 8 to 10 in. of brine above them) and a heating surface of from
700 to 1,000 square feet, a great deal of the steam supplied to them is
not condensed, and, therefore, passes from the grainer pipes into the
settler pipes (sometimes passing through a steam trap to separate the
condensed water) to heat the brine of the settlers.
The main difficulty with which the manufacturers of New York State have
to contend is the calcium sulphate. In fact, it is this impurity which
causes the interruption of the process, and the laborious cleaning out,
whether the kettle, the pan, the grainer, or the vacuum pan is used.
It not only entails a great loss of heat in consequence of its slow
conductivity, but it also causes the overheating of the metal exposed
to direct fire, wherever this is employed. Suggestions and experiments
have been made to overcome this difficulty, involving the expenditure
of great sums of money, but without any practical results as far as
mechanical means are concerned.
From the time of the introduction of the open-pan system in Cheshire,
until the beginning of the present century it was found impossible,
owing to the nature of the furnaces employed in the process, to
maintain a sufficiently high and uniform temperature to produce salt
which, without grinding, is marketed as finest table salt, or to
make more than 2 tons of salt from the consumption of 1 ton of coal.
Experiments for the purpose of economizing fuel appeared destined to
perpetual failure, and the hand-stoking of the furnaces entailed so
many variations of temperature that the production of salt crystals
of uniform size was impossible. Then, within the same decade, two
processes were invented which, between them, solved the problems that
had hitherto eluded all the efforts of the scientist, the engineer, and
the practical salt-man.
In order to understand the advantages secured by the operation of
the Vacuum System, which comes to us from the United States, it must
be remembered that, under atmospheric pressure, brine boils at a
temperature of 226° F., whereas in a vacuum of 28 in. mercury, the
boiling temperature is reduced to about 100° F. It will thus be seen
that evaporation _in vacuo_ renders it possible to use multiple effect
apparatus without causing unduly high pressure in the first vessel, and
it has this further advantage, that the low-pressure steam, in passing
through the evaporation gives up its latent heat, whereas if the steam
went to the condenser direct from the engine, the heat employed in the
steam engine would be only the difference between the heat contained
in steam at 170 lb. and the steam at 5 lb. pressure. By multiple
effect evaporation, a great economy in the amount of steam required is
effected. Between the evaporation of brine and that of other liquors,
the chief difference to be noted is that in the multiple effect system,
each pan or unit is supplied with its brine independently of the
others, and graining goes on in the pans, whereas in concentrating
other liquors the pans are fed from the first to the second and from
the second to the third. The removal of the salt from each pan has,
therefore, to be arranged for. The method of working a triple-effect
plant may be briefly described as follows--
Each of the three pans having been charged with brine to the proper
level, exhaust steam from the engines is admitted to the calandria
of the first pan in which the highest temperature is maintained. The
brine in this pan becomes quickly heated, and the steam given off
enters the calandria of the second pan, where it serves to raise the
temperature of the brine. After doing its work in the second stage,
the steam is condensed, and thus creates a partial vacuum in the first
pan. The atmospheric pressure being thus reduced, violent ebullition
of the brine in the first pan results. The same process takes place in
the second pan, owing to the calandria of the third pan acting as a
condenser of the vapour and producing a vacuum. The vapour given off by
the brine in the third pan is condensed by means of a jet condenser.
It will, therefore, be seen that the highest vacuum and the lowest
temperature exist in the third pan, while the highest temperature and
lowest vacuum are found in the first pan. As the salt is precipitated
it falls to the bottom of the pans. The bottom of each vacuum pan is
connected with the boot of a continuous bucket elevator, which is
carried in a cast-iron, water-tight casing to a level sufficiently
above that of the brine in the pans to ensure that they shall be
brine-sealed. The salt is delivered into waggons and the brine drainage
returns to the pans. The further treatment of the salt crystals varies
with the purpose for which they are required. For table salt they are
subjected to grinding, but for export they are simply allowed to drain.
The general aim of the Vacuum apparatus is to divide the boiling
process into two stages, in order to prepare the brine beforehand by
purification, and out of the purified brine to produce the purest salt
possible--chiefly by boiling under atmospheric pressure--and to acquire
another liquor of the highest content in medium salt. Balzberg, in his
_Die Erdesalz Erzeugung_, has to admit that the process results in the
most complete purification of the common salt, but in the conclusion of
his critical summary of the vacuum plant, he says: “At the same time
it must be admitted that a complicated machine, which only gains, at
a high cost, advantages that can be achieved by more economical and
simpler means is of no use in practical business. The question then
arises as to whether it is necessary, for the production of domestic or
table salt, to have pure chloride of sodium, and whether it pays to use
complicated machinery to attain this end.”
[Illustration: THE HODGKINSON PATENT SALT-MAKING PLANT]
While the largest size triple-effect vacuum plants are capable of
turning out 1,000 tons of salt per diem, with brine at or near
saturation, and produce about 6 tons of salt for the combustion of 1
ton of coal, it is a very expensive process to operate as well as to
install. The cost of the plant ranges from £26,000 to £100,000, and a
large percentage of skilled labour is required in its manipulation.
But, despite the high initial cost, and the fact that it only makes one
grade of salt, it is extremely complicated, and has to be stopped for
4 hours in each 24 for the purpose of boiling out and cleaning up the
pans, the vacuum plant is a highly efficient piece of mechanism, and
for a while it remained the best and most economic system on the market.
But the Vacuum process was not destined to remain long without a rival.
In point of fact, the merits of the American invention had scarcely
obtained recognition when a new furnace was designed which, when
applied to the open-pan system and subjected to practical tests, proved
an entire success. The late James Hodgkinson, the patentee, was not a
salt-man, but the head of a Manchester firm of engineers and machinery
manufacturers, and it was a professional visit to a salt-works which
revealed to him the crudity of the brine-boiling operation and gave
him the idea of adapting to the salt furnaces a mechanical stoker
of his own invention, which was already being operated for other
manufacturing purposes. In the development of his idea, and with his
mechanical stoker as its foundation, he perfected the Hodgkinson Patent
Salt-Making Process, the advantages of which over all other processes
for the manufacture of salt from brine have been summarized by Sir
Thomas H. Holland, D.Sc., F.R.S., under the following six heads--
1. Complete utilization of the heat derived from the fuel employed.
2. The absolute maintenance uniformly of this heat.
3. The fact that finely-divided first-quality table salt can be
produced in the dry form fit for dispatch to the market without
grinding or other preparation.
4. The fact that coarsely crystallized salt can be produced at the same
time as the finest table salt.
5. That the proportion of the different grades of salt can be varied
at will, as well as maintained constantly, to suit the varying
requirements of the market.
6. The automatic and continuous removal of the salt as fast as it is
precipitated from the brine.
The essential features of the Hodgkinson plant consist of (_a_) a
mechanically-stoked furnace for the production of heat; (_b_) a primary
closed evaporating pan, 30 ft. in diameter; (_c_) two secondary
circular pans, 25 ft. in diameter; (_d_) four open rectangular pans,
60 ft. by 25 ft.; (_e_) a series of folded steam-jacketed pipes for
heating the inflowing brine by the waste steam; and (_f_) a condensing
arrangement to produce a partial vacuum in the closed pans.
The Hodgkinson furnace is not placed under the pan, as in the old
system, but in front of the plant, and the heated gases pass under
the primary pan, where the temperature ranges between 1,800 and
2,000°F. In this primary pan is made a finer and better salt than
can be manufactured by any other system in the world. Moreover, by
means of the mechanically-stoked furnace, and the consequent uniform
high temperature, it is possible, for the first time, to control the
character of the salt produced. Where the temperature varies, as in the
open-pan system, crystals of varying shapes and sizes are produced,
and this mixed salt must be ground to make it suitable for table
purposes. Where steam heat is employed, as in the vacuum process, the
temperature is not high enough to make crystals of the smallest size.
By the Hodgkinson system the primary pan produces a precipitation which
requires no grinding, which flows in a cascade of salt from the pan,
and can be delivered to the consumer without having come into contact
with the hand of man in the whole course of the operation.
The heated gases, having passed under the primary pan, are then divided
and sent under the two secondary pans, and from thence they pass
under the open rectangular pans, the gases being distributed by the
broken columns of brickwork on which the pans stand. The temperature
of the gases passing under the open pans commences at about 600° F.,
and gradually decreases to about 200° F. under the farthest pans.
By the automatic regulation of the temperature, the waste gases
are utilized to produce salts of the various degrees of coarseness
required for the dairy, the stock-yard, and fishery purposes. In the
two secondary closed pans, finely divided table salt is also produced,
but it is possible, by opening the manhole traps in the covers, to
increase the size of the crystal and make dairy salt in these pans.
The coarser crystals and flake salts are made in the open pans in
which the crystallization is at the lowest rate. The grain of the salt
can be altered at will. In order to meet any change in the market
requirements, coarser salt can be produced at a moment’s notice in the
secondary pans. One very marked superiority of the whole system over
all other processes is seen in the fact that a change in the type of
salt produced can be immediately effected, and a constant and uniform
output of any combination of products can be absolutely guaranteed.
The improvements which the Hodgkinson plant has effected in the
open-pan system are: the increased production of from 2 to 7 tons
of salt from the combustion of 1 ton of coal, the production of the
finest table salt without grinding, and of every grade of salt from
the flour-fine table to the coarsest fishery salt, in one and the
same operation, and the saving of time that is required in all other
processes for scraping and cleaning the pans. Its superiority over the
Vacuum system lies in the facts that its initial cost is about £4,000,
as against anything from £26,000 to £100,000; that the majority of the
work being automatic, the expense of specially trained, skilled labour
is dispensed with; that it is operated for 24 hours a day as against
20; requires no grinding process in the manufacture of table salt;
and produces every grade of salt simultaneously. Sir Thomas Holland,
while studying the Hodgkinson process in operation, is said to have
exclaimed: “This is not an improvement, it is a revolution”; and in his
subsequent report upon the process, he has declared that it “has an
enormous advantage over any known process for the production of salt.”
CHAPTER VIII
THE SALT MARKET
Although no purpose would be served by dealing in detail with other of
the many schemes that have been elaborated in the past three hundred
years for the improvement of brine salt manufacture, the complete
list of patents that have been taken out for the purpose constitutes
a record of almost unrelieved failure which would occupy many pages.
It has always been obvious to every intelligent investigator outside
the little circle of salt proprietors, that the open-pan process
was a survival of the dark ages, but the principle governing the
precipitation of salt from brine is so simple that the equal difficulty
presented itself to the practical salt-men, of either effecting further
simplification or of securing further economies by the elaboration
of the process. Individuals in every generation recognized that the
methods of mediaevalism cried aloud for revision, but the salt trade
resolutely and consistently set their faces, and their hands, against
every suggested innovation. The salt-men were the avowed enemies of
Thomas Lowndes, they drove Chrysel back to Saxony, they loaded Furnival
with misfortune and landed him in gaol. In 1890, an official of the
Salt Union reflected with grim complaisance that, although no trade had
had more patents applied to it than the salt trade, no trade could show
so large a percentage of failures in the matter of reformed methods,
and since all the companies that had brought forward new plants and
processes in competition with the Salt Union had come short of success,
he piously concluded that the system which had survived the trial of
generations must be the fittest.
The opposition of the salt trade to the introduction of new methods of
manufacture is explained by the fact that the profits accruing from
the old, clumsy, crude, and wasteful process were so large that the
proprietors could see no possible reason for welcoming innovations.
Moreover, the manufacture under established conditions was in the
hands of a comparatively small number of makers, who could not adopt
new measures without letting in more men, and the long tenure of
their monopoly made the salt-men intolerant of a competitive system.
Opposition was so abominable to them that, while they would combine as
one man to keep out the daring intruder, or to crush such an one if he
succeeded in getting in, they were not at all averse from employing
similar tactics for the purpose of exterminating one another. Although
it had cost them over a quarter of a million sterling to dispose of
William Furnival, the game of price-cutting was not discontinued after
1833. In order to safeguard themselves against the periodical falls in
prices, which, if persisted in, would mean wholesale ruin, all sorts of
associations, syndicates, trusts, committees, and pools were formed for
the regulation of stocks and prices, but each successive combination
was successively abandoned, and was followed by another period of
bitter jealousy and trading loss. Between 1846 and 1880, the trade was
being continually reorganized for offensive and defensive commercial
purposes, but, in 1881, it was admitted that, in spite of all attempts
to encourage a better feeling among the leading manufacturers, “the
spirit of envy, hate, malice, and all uncharitableness, which has
so long been the bane of the salt trade, has again become rampant,”
with the result that the price of common salt--4s., less the brokers’
discount of 5 per cent.--was the lowest that it had touched since the
American Civil War. Two years later it was declared that the trade,
instead of being ruled by common sense and business experience, was
being ruined by personal animosities and trade jealousies.
The files of the _Northwich Guardian_ at this period chronicle the
development of a state of affairs which must be almost without parallel
in any other trade. During 1883 the violent competition continued,
resulting in heavy loss, the closing of many works, and a large
increase in bankruptcies. In 1884, the _Guardian_ declared that “the
battle is fast becoming a war of giants.... Capital is showing itself,
almost everywhere, a remorseless Juggernaut, crushing thousands of
victims beneath its ponderous wheels.” In that year a proposal to form
the trade into one huge company was frustrated by the bitterness of
internal jealousies. Further attempts to bring all the salt proprietors
into a combination for mutual protection and profit were made and
abandoned from the same cause. “It is easy to make laws and regulations
and to carry them out successfully when men are governed by the
ordinary laws of business and common sense,” commented the _Guardian_
in 1886, “but when sentiment or passion is allowed to interfere, it is
impossible either to make sensible laws or carry them out successfully
when made.”
In March, 1888, we read that “the great struggle for mastery still goes
on”; in April, “the process of exhaustion is not yet complete,” and the
deplorable state of the salt trade was attributed to “a few men who
seem to have made more money than they know what to do with, and are
spending it in seeing what amount of injury they can do to each other,
and as a necessary consequence to numbers of others who are innocent
of offence.” In May, a correspondent of the same journal deplored the
material damage the trade was suffering through the perversity and
selfishness of the salt proprietors, and he came to the conclusion that
their object was “not really to do business but to kill one another
out.” “Is there more morality,” he asked, “in the man of means starving
out the man without means by selling, below cost of make, than there
would be in stopping him on the highway and picking his pocket?... When
the intention in the two cases is the same--the plunder or ruin of the
opponent--how can the morality differ? It does seem a most grievous
thing that when the greater number in the trade are anxious to do
business at a profit to themselves ... they should be prevented because
a few--a very few--should think only of themselves, and care nothing
for the sufferings of others, and carry on the fight to the bitter end,
causing enormous suffering and distress....” “We can see very clearly,”
he concluded, “that if something is not done shortly to bring about a
better state of affairs, some defensive action must be taken by those
firms outside the present strife which will result in no good to the
parties now responsible for the mischief.”
The “defensive action” referred to was already being formulated,
and in October, 1888, was issued the prospectus of the Salt Union
Limited, which was formed with a capital of £4,000,000 for the purpose
of consolidating the undertakings of the Salt Proprietors in the
United Kingdom, “with a view to ending reckless competition which
injuriously affects the salt industry without conferring any adequate
advantage on the public.” By virtue of the sixty-four agreements,
covering the purchase of properties involving the inclusive payment
of £3,704,519, the Union became the greatest salt proprietors in the
world, and the success of the flotation was described as “almost
unprecedented.” Apparently the only two newspapers that had the least
dubiety concerning the success of the venture were _The Times_ and the
_Northwich Guardian_. _The Times_, while recognizing that the primary
object of the movement, viz., that of “curtailing supply and creating
an artificial scarcity”--would be gained if an effective monopoly could
be secured, pointed out that: “The Syndicate has not acquired the
control of all the mines or works at which salt is produced, and unless
they do this they will not have an absolute monopoly.” The _Guardian_
admitted that with careful management the company would prosper, but,
speaking from its intimate knowledge of the spirit which animated
the salt-trade, it cautiously predicted that the first few months’
operations would show whether the enterprise could go on successfully.
“The scheme is a gigantic one, and may prove either a great blessing or
a great curse, according to the principles on which it is conducted.
Let us hope that a spirit of justice and fairness towards shareholders,
servants, and the public at large will make the scheme a blessing.”
The warning voiced by _The Times_ with regard to the Salt Union’s
inefficient monopoly was justified almost immediately by the issue of
prospectuses of rival salt schemes, and although opposition of this
kind was treated by the Union with affected contempt, and the public
was assured that the insignificant salt lands secured by rash outsiders
were “such as to break the hearts of all investors who might visit
them,” the fact remained, as was noted in November, 1889, that “the
most remarkable thing in connection with salt has been the continuous
fall in the price of Salt Union shares.” The principle on which the
valuation of the Union’s acquisitions was made did not transpire,
but _The Times_ understood that “the selling price has been quite
satisfactory to the vendors,” and the Chairman of the Union, in 1896,
was feign to confess that “never were covenants so ingeniously framed
as to cause lawsuits.” It is not overstating the case to say that the
terms upon which the Salt Union purchased their properties provides
one of the most amazing instances of reckless optimism in the history
of comparatively modern finance, and the subsequent administration of
the Company’s affairs was as unfortunate as the preliminary settlements
had been disastrous. In one law case with a vendor from whom they
had purchased for £600,000 a property which their own representative
valued at £400,000, they had to pay a further £60,000, and they
settled another action by selling for £125,000 a tract of land which
they had originally acquired for £372,000. In 1895, they increased
their capital to £4,200,000 by issue of further debentures to the
amount of £200,000; and, in 1901, the capitalization of the Union was
reduced to £2,600,000. Up to 1913, they had paid away £117,451 for
directors’ fees, travelling expenses, etc., £99,236 for preliminary
and Parliamentary expenses, law charges, etc., and £723,985 for
administration charges, and from 1896 to 1914 they had only paid (in
1907) one dividend of ½ per cent. on the ordinary shares.
INDEX
Agricola (Georgius) on salt-making, 15, 18, 56
America, salt-making in, 127–135
--, vacuum system in, 135
Brine, battle of the, 121
--, composition of, 7
--, economy in production of, by Furnival, 78
--, evaporation of, 3
--, Dr. Jackson on the process, 56–60
--, old reservoirs of, 104
--, output at Northwich, 53
--, treatment of, in early days, 40
Brine-making, methods of Dr. Jackson, Rastel, Lowndes, Brownrigg,
Chrysel, Furnival, Holland, 56–73
Brine-tapping, improved process described, 106, 107
Camden’s _Britannia_, derivation of suffix “wich,” 32
--, supply and treatment of brine described, 40, 42
_Chambers’s Journal_, a subsidence described, 113, 114
Cheshire, the “wiches” of, 32, 34
--, extent of deposits in, 83–96
Chrysel, persecution of, 71
Domesday Book, references to salt works in Cheshire, rules governing
the trade, 34–37
Droitwich, salt-making there, A.D. 816, 33
Furnival, Wm., introduces steam heat, 76
--, economy in production by; alarm of salt proprietors, 78
--, persecution of, a victim to Cheshire salt proprietors, 76–82
--, his patents, 77;
--, his end, 82
Hodgkinson (Jas.), his system, 76, 138–141
Holland (Philemon), 32
Holland (Sir Thos.), his eulogy of the Hodgkinson process, 141
Jackson, (Dr. W.), 56
Johnson (Geo.), account of treatment of brine by, 42, 43
King’s Vale Royal, particulars relating to Cheshire salt districts,
43, 44
Lakes, or “Flashes,” 103, 104, 112, 113
Lowndes (Thos.), improved method of brine-making by, 62, 65
--, persecution of, 71
Marbury, discovery of salt at, in 1670, 97
Marbury Pipe, 54, 122, 123
Martindale (Adam), Communication to Royal Soc., 97
Mendeléeff, on crystallization, 5
Middlewich owners and number of salt-houses at, 51
--, output at, 54
Nantwich owners and number of salt-houses at; decline of industry at,
51, 53
Nevada, rock-salt at, 3
New York, salt-springs in; methods employed there, 127
Northwich, Adelaide Marston mine, 98
--, earliest manufacture in England, 32
--, output of brine at, 53
--, the “Walling Booke” of, 48
Ormerod, on the origin of the salt field of Cheshire, 84, 85
Rainfalls, cycles of, affecting salt deposits, 91
Rastel (Dr. Thos.), method of evaporation of brine at Droitwich, 60–62
Rock-salt, purest in Hungary, 1;
rarely found pure, _ib._
Rock-salt Mining--a dead industry; method of working, 101–103
Royal Society, _Phil. Trans._, 56, 60
Rumania, deposits in, 20, 26
--, estimated reserves and annual output, 28
Salt, Adelaide Marston mine, 98
--, ancient orders concerning, 44–48
--, beginnings of the industry, 8, 9, 10
--, chemistry and properties of, 1
--, Chinese methods of making, 11
--, colour of, 2
--, convict labour, 20
--, crystals in, 4
--, decline of industry at Nantwich, 52, 53
--, depth and thickness of deposit at Northwich, 90
--, discovery of, at Marbury in 1670, 97
--, Domesday Book--reference to salt in A.D. 1084, 33
--, earliest manufacture in England, 32
--, effect upon sea-water, 2
--, experiments for removal of impurities in, 30, 31
--, formation and extent of Cheshire deposits, 83–96
--, importation of, 38
--, Italian method of making, 12
--, Japanese methods of making, 12
--, lectures on, by Ward (Thos.), 126
--, Mendeléeff on, 6
--, method of working top and bottom beds, 100
--, name first given, 1
--, Portuguese and Spanish method of making, 14
--, preservative property of, 6, 9
--, Rastel’s account of clarifying, 61, 62
--, solubility of, 2
--, symbol of sanctity, 9
--, theories respecting deposits, 85–90
--, Prof. Thompson’s calculations, 92–96
--, value in agriculture, 6
Salt-beds, area of Cheshire, 92
“Salt-licks,” 8
Salt-makers, conservatism of, 18
Salt-making, methods of, 125–129
--, methods employed in America, 127, 135
--, processes of, 127
--, vacuum system, 135, _et seqq._
Salt-Market, the, 142–147
--, mines, collapse of, various dates, 103, 107, 108
Salt-pans, recovery of old, 39
Salt-trade, competition in, 144, 145
Salt Union, 54
-- --, alleged rights of, 123, 124
-- --, “Battle of the Brine,” 121
-- --, brine carrying by, 122, 123
-- --, large capital of, 145
-- --, newspaper comments, 146–147
-- --, opposition to new processes by, 142
-- --, Wharton Works, 79–81
Subsidences, 97–123
--, causes of, 108–112
--, described 113
--, damage to property, 115, 116
--, Compensation Bill, 120, 121
--, legal aspects of, 117–121
--, resentment of townspeople, 117
--, pumpers responsible for, 117
Thompson (Prof. Jas.), his calculations, 92–96
“Wallers,” derivation of name, 40
“Walling Booke of Northwich” (Harleian MS. in British Museum
containing earliest list of “wich-houses” and their owners),
48, 50, 51
Ward (Thos.), lecturer on salt, 126
“Wich,” derivation of the name, 33
Wieliezka rock-salt at, 1
--, works at, 20–26
Winsford, output at, 53, 55
THE END
_Printed by Sir Isaac Pitman & Sons, Ltd., Bath, England_
Transcriber’s Notes
Punctuation, hyphenation, and spelling were made consistent when a
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