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.