DIES.
The dies for coining are prepared by engravers, especially employed at the Mint for that purpose. The process of engraving them consists in cutting the devices and legends in soft steel, those parts being depressed which, in the coin, appear in relief. This, having been finished and hardened, constitutes an “original die,” which, being the result of a tedious and difficult task, is deemed too precious to be directly employed in striking coins; but it is used for multiplying dies. It is first used to impress another piece of soft steel, which then presents the appearance of a coin, and is called a hub. This hub, being hardened, is used to impress other pieces of steel in like manner which, being like the original die, are hardened and used for striking the coins. A pair of these will, on an average, perform two weeks’ work.
Transfer Lathe.
The transfer lathe, a very complicated piece of machinery, is used in making dies, for coins and medals. By it, from a large cast, the design can be transferred and engraved in smaller size, in perfect proportion to the original.
The Coining and Milling Rooms.
This department, the most interesting to the general visitor, occupies the larger portion of the first floor on the east side of the building. The rooms are divided by an iron railing, which separates the visitors, on either side, from the machinery, etc., but allows everything to be seen.
