COIN, a piece of metal, circulating as money with an official certified impression as to weight, fineness and value. United States coin as described further on is nine-tenths fine; that of Great Britain 'eleven-twelfths fine. The place where coin is manufactured is called a mint and it is always a monopoly exercised by an established government. The mint of the United States was author ized by Act of Congress 1792, and its general operations began in 1793. At that time the appliances of coinage were few and crude, the striking of coin being by the old screw hand-press and the annual out put confined to narrow limits. It was not until 1836, when the mint was removed from Seventh street, Philadelphia, to more commodious quar ters at Chestnut and Juniper streets, that im proved appliances were introduced. At that time the steam-operated coining-press invent ed by M. Thonnelier, a Frenchman, was intro duced, and greatly facilitated the process of minting. Twenty years later this press was re modeled and much 'improved, continuing in use for 14 years, when it was superseded by the perfected machines now in use. The introduc tion of the steam coining-press inaugurated the improvements which have made the mint of the United States one of the finest equipped mints in the world. From 1836 to the present time the progress of the mint has been largely ex perimental. New and improved machinery has been added from time to time and improved scientific processes have been adopted. The humid assay process for determining the fine ness of gold and silver was introduced in the year 1836. The platinum apparatus for the as say of gold was introduced in 1867. This was an English invention and a great improvement upon the method formerly in UST. Automatic machines for the separation of coin blanks into "standard," °heavy," and condemned "light" pieces were introduced in 1877. Im proved rolls for converting ingots into coin strips, as well as gas annealing furnaces, may be said to have completed the equipment of the mint.
The organization of the mint, under the original and subsequent Acts of Congress, and until 1873, provided for a director, located at the parent mint at Philadelphia, an assayer, melter and refiner, coiner and engraver of dies, with a necessary subordinate clerical force, the assayer, melter and refiner, coiner and en graver, being designated as "operative officers." The director was subject to the orders of the Secretary of the Treasury. After the creation
of branch mints and assay offices the heads of such institutions reported to the director at Philadelphia. By the Act of 1873 the mint was reorganized, with a bureau at Washington, where the director was located. The resident chief officer at the mint was by that Act desig nated as superintendent, ranking with the chief officers of the mints at San Francisco and at New Orleans and the chief of the assay office at New York. The chief officers of the branch mints and minor assay offices were designated as "assayers-in-charge," reporting to the di rector at Washington. The mint service is now under this reorganized form. The super intendents and the operative officers are ap pointed by the President and hold their offi cial positions at his pleasure.
The processes of the mint can best be con sidered under the head of routine. The mint purchases at its counter all gold presented in value not less than $100, providing the deposit is not too base for commercial conversion into coin or fine bars. All deposits are made with the weigh clerk at the weigh room, who care fully weighs the same on the delicate balances, which are adjusted to show variations of one hundredth of a troy ounce. The weight is care fully recorded in the books of the weigh clerk and registrar of deposits, together with the de scription of the bullion and the name of the depositor, both officers being present and care fully noting the same. The deposit is then locked in a copper box and sent to the deposit melting room, where it is melted and cast in the form of a bar. From this bar the assayer cuts clips, weighing from 18 to 20 one-hundredths of an ounce, two clips being taken, one from the upper side at one end, the other from the under side at the other end. These clips are assayed separately to determine the homoge neity of the metal. This assay determines the proportions of fine metal in the bar, and upon this assay the money value is determined and the depositor is paid. The loss of weight by melting is carefully noted and recorded. A slight allowance is made after melting to the melter and refiner and the weight so estab lished becomes the true weight. As soon as the fineness of a day's deposits is reported by the assayer, they are delivered to the melter and refiner, and by that officer sent to the refinery, where the silver is separated from the gold and the base metals eliminated wholly, only the precious meals being accounted for.