Illustrated history of the United States mint / with a complete description of American coinage, from the earliest period to the present time

by Unknown

The Melting Rooms

are on the first floor, in the west side of the building. Here all the metal used in coining is alloyed, melted and poured into narrow moulds. These castings are called ingots; they are about twelve inches long, a half-inch thick, and vary from one to two a half-inches in breadth, according to the coin for which they are used, one end being wedge-shaped to allow its being passed through the rollers. The value of gold ingots is from $600 to $1,400; those of silver, about $60. The fine gold and silver bars used in the arts and for commercial purposes, are also cast in this department.

CASTING INGOTS.

INGOTS.

These are stamped with their weight and value in the deposit room. The floors that cover the melting rooms are made of iron in honey-comb pattern, divided into small sections, so that they can be readily taken up to save the dust; their roughness acting as a scraper, preventing any metallic particles from clinging to the soles of the shoes of those who pass through the department, the sweepings of which, and including the entire building, averages $23,000 per annum, for the last five years.

The copper and nickel melting rooms, wherein all the base metals used are melted and mixed, is on the same side and adjoining to the gold and silver department. Up to the year 1856, the base coin of the United States was exclusively copper. In this year the coinage of what was called the nickel cents was commenced. These pieces, although called nickel, were composed of one-eighth nickel; the balance was copper.

The composition of the five and three cent pieces is one-fourth nickel; the balance copper. The bronze pieces were changed in 1859, and are a mixture of copper, zinc and tin, about equal parts of each of the two last; the former contributing about 95 per cent. There are seven furnaces in this room, each capable of melting five hundred pounds of metal per day. When the metal is heated and sufficiently mixed, it is poured into iron moulds, and when cool, and the rough ends clipped off, is ready to be conveyed to the rolling room.