Silver, which was formerly, concurrently with gold, a legal tender to any amount, has, by 56 George III. c. 68, ceased to be so. There is a seignorage on both silver and copper money, amounting in silver to 10 per cent, when the price of silver is 5s. per ounce, which, however, from the tear and wear of the coin, brings small profit to the crown. On the copper coinage the seignorage is no less than 100 per cent on the average price of copper. The profits of the seignorage, formerly retained by the master of the mint to defray the expense of eoinage, have, since 1837, been paid into the bank to the credit of the consolidated fund.
A new mint was erected on Towerhul in 1810. In 1815 some alterations were made in its constitution; and in 1851 a complete change was introduced in the whole system of administration. The control of the mint was vested in a master and a deputy master, and comptroller. The mastership, which had in the early part of the present century become a political appointment held by an adherent of the government, was restored to the position of a permanent office, the master being the ostensible executive head of the establishment. The operative depl•tment was intrusted to the assayer, the inciter, and the refiner. The moneyers, who had from early times enjoyed extensive privileges and exemptions, and were contractors with the crown for the execution of the coinage, were abolished, and the contracts with the crown were entered into by the master of the mint, who also made subordinate contracts for the actual manufacture of the coin. Farther changes were made on the administration of the mint in 1869. The mastership was added to the duties of the chancellor of the exchequer, without any addition of salary, and the offices of deputy master and comptroller were amalgamated. A yearly saving of £10,000 is believed to have been effected by the changes of 1851, and a further £8,000 by those of 1869, with an increase of efficiency. It is at present in contemplation to remove the mint from Towerbill to the rear of the Thames embankment at White friars, with new and improved Mints have lately been established at Sydney and Melbourne to coin the gold so largely found in Australia.
Processes of Coining. —Down to the middle of the 16th c. little or no improvement seems to have been made in the art of coining from the time of its invention. The metal was simply hammered into slips, which were afterwards cut up into squares of one size, and then forged round. The required inipmision was given to these by placing them in turn between two dies and striking them with a hammer. As it was not easy by this method to place the dies exactly above each other, or to apply proper force, coins sp made were always faulty, and had the edges unfinished, which rendered them liable to be clipped. The first great step was the application of the screw, invented in 1553 by
a French engraver of the name of Brusher. The plan was found expensive at first, and it was not till 1662 that it altogether superseded the hammer in the English mint The chief steps in coining as now practiced are as follows: The gold or silver to be coined is sent to the mint in the form of ingots (Ger. einyiessen, Du. ingieten, to pour in, to cast), or castings; those of gold weighing each about 180 oz.,while the silver ingots are much larger. Before melting, each ingot is tested as to its purity by assaying (q.v.), and then weighed, and the results carefully recorded. For melting the gold, pots or crucibles of plmnbago are used, made to contain each about 1200 oz. The pots being heated white in furnaces, the charge of gold is introduced along with the proper amount of copper (depending upOn the state of purity of the gold as ascertained by the assay). to bring it to the standard, which is 22 parts of pure gold to 2 of copper (see ALLOY). The metal when melted is poured into iron molds, which form it into bars 21 in. long, 11 in, broad, and 1 in. thick, if for sovereigns; and somewhat narrower if for half-sovereigns. For melting silver (the alloy of which is adjusted to the standard of 222 parts of silver to 18 of copper), malleable iron pots are used, and the metal is east into bars similar to those of gold.
The new copper, or rather bronze coinage, issued in 1860, is an alloy consisting of 95 parts of copper, 4 of tin, and 1 of zinc. The coins are only about half the weight of their old copper representatives. The processes of casting and coining the bronze are essentially the same its in" the case Of gold and The operation of rolling follows that of casting. It consists in repeatedly passing the bars between pairs of rollers with hardened steel surfaces, driven by the rollers being brought closer and closer as the thickness becomes reduced. At a certain stage, as the bars become longer, they are cut into several lengths; and to remove the hardness induced by the pressure they are annealed. The finishing rollers are so exquisitely adjusted that the fillets (as the thinned bars are called) do not vary in thick ness in any part more than the ten-thousandth part of an inch. The slips are still further reduced in the British taint at what is called the "draw bench," where they are drawn between steel dies, as in wire-drawing, and are then exactly of the necessary thickness for the coin intended.