in 1788, and a colonial bronze coinage was executed at this establishment as recently as the year 1875. There is another mint in Birmingham worked by a private company (“The Mint, Birmingham, Limited”), where coinages for foreign governments are executed and in addition silver and bronze colonial coins are occasionally manufactured under the supervision of the London Mint. The existing London Mint was erected on Tower Hill in 1810. Minting in Scotland began in the reign of David I. (1124–1153) and ceased in 1709, two years after the Act of Union, in which it had been expressly stipulated that a mint should be continued in Scotland.[1] Coinage in Dublin began in Anglo-Saxon times and came to an end in the reign of William III.[2] The other Irish mints were of little importance.
British Dominions.—Turning to mints in British Dominions beyond the Seas, Ruding enumerates twenty-six mints in France and Flanders used by British monarchs between 1186 and 1513, and Anglo-Hanoverian coins were struck at Clausthal, Zellerfeld and Hanover in the period 1714–1837. In India[3] the earliest English mint was that at Madras which was bought by the East India Company in 1620, reorganized more than once and finally closed in 1869. The Calcutta mint was established by the East India Company in 1757, but other mints in Bengal continued to be used till about 1835, when the Calcutta mint was rebuilt. The Bombay mint was set up about the year 1671, but the coins were made by hammer and anvil until 1800. The Calcutta and Bombay mints are still in operation. A mint was opened in Hong-Kong in 1866 but was closed in 1868 and the machinery sold to Japan. In Australia there are three mints, Sydney, opened in 1855, Melbourne, opened in 1872, and Perth, opened in 1899. Up to 1909 only sovereigns and half-sovereigns were struck at these establishments, but in 1910 arrangements were made for a Commonwealth silver coinage. A mint at Ottawa was opened in 1908 for the manufacture of all Canadian coins as well as English sovereigns.
Other Countries.—In the United States the Philadelphia mint was opened in 1792, but only manual or horse power was used until 1836, when steam was introduced. Other mints are now in operation at New Orleans, San Francisco and Denver. In most European countries a single mint situated at the capital is found to be sufficient, but there are six mints in the German Empire and two in Austria-Hungary. In China 26 mints were at work in 1906. There are also mints at Osaka, Bangkok and Teheran, and the Seoul mint was at work in 1904. In Mexico 11 mints formerly existed, but one only, in the city of Mexico, remained open in 1907. In South America there are mints at Lima, Santiago, Buenos Ayres and Tegucigalpa. No mints are in operation in Africa. In all there are nearly 70 mints in the world.
The Supply of Bullion to Mints.—In England, in the middle ages, the king was accustomed to send in to the mint the produce of his own silver mines, and claimed the exclusive privilege of purchasing the precious metals. The right of levying seigniorage, however, was sometimes waived by the king to encourage his subjects to bring gold and silver to the mint, and several instances are recorded in which the aid of alchemists was called in to effect the transmutation of baser metals into gold. Seigniorage was abolished for both gold and silver in 1666, when it was provided that no charge should be made at the Mint for coining and assaying. Finally in 1816 the free coinage of silver was brought to an end. At present all gold bullion brought to the Mint is weighed and portions are cut off for assay. The amount of gold in standard ounces (916·6. fine) corresponding to the “imported” bullion is thus ascertained, and on the application of the importer the gold is coined and delivered to him in the form of sovereigns and half-sovereigns at the rate of £3, 17s. 1012d. per standard ounce troy, no deduction being made for wastage, seigniorage, the purchase of alloy metal, or the expense of manufacture. As a considerable time elapses between the receipt of bullion by the Mint and the delivery of the coin, it is generally more profitable for the holder of gold bullion to sell it to the Bank of England or dispose of it in some other way. The result is that the gold presented for coinage is almost always sent from the Bank of England, which suffers no loss of interest during the coinage of the bullion, because bank-notes have already been issued against it. Silver bullion, and the copper, tin and zinc required to make up bronze, are bought by the Mint and manufactured into coin, which is kept in stock and issued as it may be required. One ounce of standard silver, which contains 925 parts of silver and 75 of copper per 1000, is converted into 5s. 6d. in silver coin, whatever may be the market price of silver bullion. This seldom exceeded 30d. per ounce in the years 1893–1907. Coinage bronze consists of copper 95 parts, tin 4 parts and zinc 1 part, and a ton yields £448 in pence or £373, 6s. 8d. in halfpence or farthings. The difference between the nominal value of silver and bronze coin and its intrinsic value is retained by the state to cover the expenses of manufacture and as a source of profit. It corresponds to the seigniorage levied by the king on all coinages down to the reign of Charles II. In return the Mint receives at its nominal value for recoinage the worn gold and silver coin which is withdrawn from circulation by the Bank of England and some other banks. In spite of the cost of this recoinage, however the profit on the issue of new silver and bronze usually exceeds in each year the total expenditure of the Mint. Gold and silver are delivered in a refined state suitable for immediate conversion into coin. In general, only old coin, ingots resulting from the melting of coin, and “fine” ingots are received. Fine gold ingots (the “bar gold” of commerce) are usually about 400 oz. troy in weight, and contain from 990 to 999·5 parts of gold per 1000, the remainder being chiefly silver. Fine silver ingots usually weigh from 1000 to 1200 oz. troy and contain from 995 to 999 parts of silver per 1000. The ingots are valued by weighing and assaying, and a calculation is made as to the amount of copper required for melting with them to produce the standard alloy. The two standard alloys consist respectively of gold 916·6. copper 83·3. and of silver 925, copper 75. All gold coins received at the Bank are weighed on automatic balances (see below) and those below the lowest legal current weight are separated. The lowest current weight is 122·5 grains for sovereigns and 61·125 grains for half-sovereigns corresponding to losses by wear of about 0·6% and 0·8% respectively. The average age on withdrawal is about 24 years for sovereigns and 15 years for half-sovereigns. Silver coins are not weighed but are selected for withdrawal when they present a worn appearance. The average deficiency in weight of worn silver coin received at the Mint is from 8 to 10%, and the mean age somewhat less than 50 years. In European mints generally little difficulty is experienced in procuring refined gold and silver for coinage. In Australia, the United States, Japan and some other countries, the Mints receive unrefined gold from the mines and refine it before it is coined. A charge for refining is made in all cases. A refinery was attached to the London Mint from 1816 to 1851, but was then let on lease and left to private enterprise. The operations employed in the manufacture of gold and silver coin are as follow:—
(1) Melting the metal and casting it into bars. (2) Rolling the bars into strips or “fillets”. (3) Cutting out disks or blanks from the fillets. (4) Adjusting the weight of the blanks (this is omitted in some mints). (5) “Marking” or edge-rolling the blanks to produce a raised rim or to impress a design on the edge. (6) Annealing the blanks and (in some mints) cleaning them in acid. (7) Striking the blanks between dies surrounded by a collar. (8) Weighing each coin. Among the incidental operations are (а) the valuation of the bullion by weighing and assaying it; (b) “rating” the bullion, or calculating the amount of copper to be added to make up the standard alloy; (c) recovering the values from ground-up crucibles, ashes and floor sweepings (the Mint “sweep”); (d) assaying the melted bars; (e) “pyxing” the finished coin or selecting specimens to be weighed and assayed; (f ) “telling” or counting the coin.
Melting.—Formerly bullion was melted in crucibles made of refractory
clay, but they are liable to crack and require careful handling.