Tin forms the principal ingredient in various kinds of pewter and other white metallic alloys, which are manufactured into domestic utensils by casting, stamping, and other processes in which much in. genuity Is displayed. The Britannia metal manufacture was commenced on a largo scale at Sheffield, where it is still carried on, about the year 1770; and the brilliancy, lightness, and cheapness of the wares, which. when well made, greatly resemble silver, have secured for them a very extensive sale in this and other countries. The tin is first melted and raised to a red heat in A cast-iron pot, and then antimony, copper, and brass are successively peered Into it from the crucibles in which they have been melted ; the mass being stirred during the operation, tc complete the mixture. The fusion being completed by the continued application of fire under the pot, the metal is removed by ladles to cast-iron boxes or moulds, in which it is cast into slabs fifteen inches long, six inches wide, and one inch thick ; or if for casting small articles, into smaller moulds to form it into convenient ingots. The thick slabs of metal are then extended by passing them betweer polished steel rollers until they are reduced to the required degree of tenuity. The principal consumption in for candlesticks, tea-pots, coffee. and other vessels for containing liquids. The feet of candle. sticks, the bodies of tea-pots, and other articles having embossed work, are stamped between dice; and when the shape of the artich will not allow it to be stamped in one piece, it is stamped in lathes which aro subsequently fitted and soldered together. Articles ap preaching the globular form may in like manner be stamped in three or more pieces. Plaster casts are produced of the required pattern cithsr from ork;inal models or designs, or from manufactured article d silver ; and from these are made moulds or diem of fine hard pig-iron, which, with a very little finishing, form dies fit for stamping so tract sble metal. NN hen very thin, it may even he stamped in dies of maas or of spoon-metaL The great facility with which this alloy may e moulded to any required form is Illustrated by the operation termed pinning, by which the bodies of tea-pots with concentric circular swells are usually formed. [SetxatNo.) Many small vessels, spoons, and Aber articles are cast in an alloy somewhat harder than that which is rolled into sheets. The facility with which Britannia metal may be run into any shape and cut in the lathe, as for turning inea.ftures and small vessels previously formed by casting, is a great recommendation to the manufacturer. Articles of this metal are cleaned from the oil, resin, and other impurities acquired during their formation, by boiling in water containing soap; after which they are polished, either by hand, or more commonly by the buff and brush set in motion by a steam-engine. After butting and brushing, the articles are boiled in a solution of pearlash, and finally hand-brushed and band-polished by an application of soft soap, a little oil, and powdered rotten-atone. This operation is usually performed by females ; as it is found that no in strument can supply an effectual substitute for a soft hand, which is one of the first requisites inquired for when persons apply for work in this department.
Produce and Trade.—The history of the trade in tin commences with the very earliest records of commercial intercourse with the British islands. We shall only notice it, however, as it has existed within the last two centuries. Daveuant gives some interesting information concerning it soon after the middle of the 17th century. ]n 1663 our
exports of tin to all foreign countries amounted to 153 tons; • in 1669 to 240 tons; in the three years of peace, from 1698 to 1700, on All average to 1297 tons ; and in the ten years of war, from '1700 to 1710, on an average to 1094 tons. La these last ten years the annual pur chases of the Dutch amounted to 300 tons, of the estimated value of 21,374/. But the produce of the mines more than kept pace with the increased demand ; and when Davenant wrote, Queen Anne had between 4000 and 5000 tons of tin on band, a quantity equal to four or five years' consumption. The produce of the mines went on increas ing, and the accumulation to which. Daveuant alludes is only half a year's produce of the mines at present. From 1750 to 1785 the produce of the mines varied from 2273 tons to 3005 tons ; the average price being 64s. 6d. per cwt. From 1789 to 1816 the annual average quantity was 2875 tons at 79ft. Pd. per cwt. From 1817 to 1887 inclusive, the annual average was 4211 and the average price paid to the tinner was 73s. the cwt. In 1787 Banst tin was imported into this country for the first time, and the price of Cornish tin soon fell to 58s. the cwt., and would have declined still further if a new market had not been opened. The purser of an lndiarnau, who took some tin from the Molucca islands to China in 1787, found the speculation so profitable that the East India Company were induced to direct their attention to the trade, and the Company entered into arrangements with the Cornish tinners for an annual supply. The purchases of the company were made at low prices, but the tinners were indemnified by the artificial scarcity which raised prices in the home market. At first the Company paid only 08/. 1 Ss. 4d. the ton, delivered on board in London ; this gradually rose to SOL The connection 'finally ceased in 1817, as the supply of the home market hail become more profitable.
On account of the increasing consumption at home, the portion exported gradually lessened from 7-10ths to 1-5th of the whole. Most of the foreign tin imported is for re-exportation; for it can be supplied to the continent cheaper than English tin. A duty was formerly paid upon all tin raised in Cornwall, to the duchy ; but as the mode of stamping the blocks, for the estimation of duty, was very inconvenient, the duty was commuted in 1838 for a perpetual annuity ; the duty amounted to about 5s. per 120 lbs. Under the tariff of 1842, foreign tin-ore was rendered admissible on payment of a customs' duty of 50s. per ton. At present the duty is very light—free if unmanufactured, and 10s. per cent. if manufactured. The produce of the liritish tin mines from 1848 to 1855 varied from 6000 to 7000 tons a year. In 1857 it reached the large amount of 10,000 tons. So varying is the quality, that the price in the last-named year ranged from 1S1. to Int ; the total value was 750,000L, giving an average of about 75l. per ton. This was the value of the ore itself. The metallic tin, after smelting and refining, ranged from 108/. to 146/. per ton. The English mines which were moat productive in that year were the Great Huel Vor, Doleoath, Cam Brea, Par Consols, and Providence; the produce ranged from 54,000/. down to 23,0001., from these five mines.
In the last financial year (1860), there was imported 58,000 carts. of tin, in blocks, ingots, 'bars, and slabs; and the exports in the same year amounted to 55,000 cwts. of unwrought tin, besides 1,500,000/. in value of tin-plates, in which the greater part of the weight is of iron.