In giving a historical sketch of the produce of the tin-mines in England, we shall not go farther back than the commencement of the 18th century. At this period, the mines which had been neglected during the civil wars, were again wrought with effect and success, pro ducing, one year with another, rather more than 1600 tons: From i720 to 1740, the annual average produce was 2100 tons; from 1740 to 1750, 2500 ; from 1750 to 1760, 2658; from 1760 to 1770, 2728; from 1770 to 1780, 2750; from 1780 to1790, 2958; from 1790 to 1800, 3245 tons. From the last period the mines seem to have been on the decline.
There is undoubted proof that the lead-mines of this country, at least those in Derbyshire, were wrought in the time of the Romans, this metal having been export ed A. D. 14 ; and at the time of the Conquest it was used to roof churches. In 1189, the exportation of it was carried to a considerable extent. During all this period, however, it would seem that no mines of this metal were known, or at least wrought, except those in Derbyshire. In the year 1289, lead-mines were disco vered and wrought in Wales; and the circumstance be ing ascertained, that the ore of these mines produced some silver, increased attention and alacrity were given to the working of the mines of this metal. The pro duce of the lead-mines at present wrought in England cannot accurately be ascertained ; those of Derbyshire are supposed to produce annually an average of between 5000 and 6000 tons, but to be on the decline; those on the borders of Cumberlqnd and Northumberland are calculated to produce 150,000 pigs of 1 f cwt. or 11,250 tons annually : The Cumberland employ upwards of 1000 men. The other metals which are found in Eng land do not require any particular notice, except the black lead of Cumberland ; the manganese of the Men dip Hills, and the zinc of Derbyshire. The first is of excellent quality, and in great demand for pencils, cru cibles, Sec. No more is wrought than is absolutely ne cessary to supply the demand, without lowering the price. The manganese of the Mendip Hills is become much more valuable than it formerly was, in consequence of the mode of bleaching by the oxymuriatic acid, in which it is largely employed. The quantity of ore of zinc produced in Derbyshire, is about 500 tons annually. It is inferior in value to the calamine of Mendip. Be sides calamine, blend, or black jack, another ore of zinc, but less valuable than calamine, is got in Derbyshire.
The salt pits of Cheshire and Worcestershire appear to have been wrought at a very early period : those of the former county are supposed by Mr Pennant to have been known to the ancient Britons ; and the salt pits in Worcestershire were certainly wrought before the Con quest. In 1389, a licence was given for making salt at Middlewich; but nearly 150 years after this, salt appears to have been so rare an article in England, that it was stipulated, that a quantity of it should be delivered an nually by the king of France to this country. It is ra ther a singular circumstance, that though the brine pits were known so early, the pits of rock salt were not dis covered in Cheshire prior to the year 1670. The quan tity of rock salt made in Cheshire seems rather to have declined within these few years. The annual from the pits is between 50,000 or 60,000 tons, while the brine pits supply about 45,000 tons. At Droitwich, in
Worcestershire, the salt made and sold in one year ave rages upwards of 600.000 bushels ; of which, about one sixth is sent abroad. The duty paid by the pits near this place into the salt-office in London, in the year 1771, was 61,4571. ; at that time nearly one third of the whole revenue from salt in England. The revenue from the salt made in Cheshire, however, is of so much more consequence, that a particular board is appointed for its collection and management, independent of the boards of customs and excise. It is estimated, that the home consumption of Cheshire salt is 16,000 tons, and the quantity exported about 140,000 tons. The following particulars will still farther illustrate the nature and ex tent of the produce of the salt pits in Cheshire and Worcestershire. In the year 1798, 816,731 bushels of rock salt were exported ; of which, 651,820 were sent to Ireland, 54.800 to Germany, 49,800 to Russia, and 37,542 to Denmark. In the same year, 4,138,417 bu shels of white salt were exported ; of which, 910,272 were sent to Prussia, 892,430 to the United States of America, 676,624 to Russia, 407,152 to Denmark, 401,464 to Ireland, 366,103 to Germany, and 298,871 to British America. In 1799, the exportation of rock salt had considerably increased, the quantity being 1,336,625 bushels; of which, 894,975 were sent to Ireland, 167,600 to Denmark, and 163,317 to Prussia. This year the ex portation of white salt had rather declined, the total ex portation amounting to 4,132,182 bushels ; of which, 1,254,027 were sent to Prussia, 1,026,617 to the United States. 349,360 to Russia, and 368,565 to Ireland. In the year 1800, the exportation of rock salt had again rather increased, the total qte,ntity amounting-to 1,397,571 bu shels ; of which were exported to Ireland, 340,652 to Prussia, and 173,098 to Russia. The expor tation of white salt in 1800, was greater than it had been in either of the two former years, the total quantity be ing 4.338,542 ,w•.1.( Is; of wnieh, the United St rtes took 1,436 085, Prussia 9S0,250. British America 551 958, and Russia 481,501. About 70,000 bushels arc usually sent to Africa. It must be remarked, however, that the white salt includes what is made at the salt-pans, the Princi pal of which are at Lymington in EI impshire, S indwich in Kent, and on the coasts of Essex, Durham, and Nor thumberland. These we have mentioned here, from their connection with the subject of the salt mines, though not strictly in .their place. The total number of salt works in the kingdom is between 180 and 190 ; and there are upwards of twenty refineries for rock salt. The salt sent coastwise during the year above specified, was as follows : British white, 5,631,562 bushels ; of which, 3,827.510 were sent from Liverpool, 953,664 from the port of Gloucester, 229,312 from Bristol, 149,839 from Lymington, 145,983 from Hull, 116,948 from Sun derland, and 95,563 from Newcastle. During these years, 165,985 bushels of rock salt were sent coastwise, all from Liverpool. During the same years, 61,793 bu shels of foreign white, and 3250 of foreign rock salt were sent coastwise. The total consumption of salt by the inhabitants of England and Wales, is supposed to be 60,000 tons annually, besides what is used in the fisheries, for curing meat, &c.