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.”
THE GREAT CANAL-BURST AND LANDSLIP, OWING TO SUBSIDENCE NEAR NORTHWICH, 21ST JULY, 1907