Eastern Corridor.
Opening into the eastern corridor are the rooms of the Superintendent, the Chief Clerk, and the library of Historical and Scientific Works, including many valuable books upon the art of coinage. Passing out upon the gallery, we enter the Machinists’ and Engravers’ rooms. Here are engraved and finished the dies used in this Mint and in all the branch mints. Visitors are not ordinarily allowed access to these rooms, or to the assay office, or to the cellar. (In the latter are a number of immense vaults, and in the main cellar are engines, which supply the power and light used throughout the building.) Here are also blacksmith, carpenter, and paint shops; and in the rear, west side, is the medal-striking room, where medals are struck by a screw press, worked by hand. The cellar also contains the “sweep” grinding rooms. Near this room are the wells, which are receptacles for the water used in washing the precious metals. These wells are cleaned out every few years and the deposit is then treated in the same way as the sweepings.
The little wooden building in the court was formerly the cent-room, where copper cents were exchanged for nickels;[10] it is now the office of the agent of the Adams Express Company, who brings to the Philadelphia Mint millions of dollars worth of precious metals in the shape of bullion from the far west, to be converted into American Coin, when it is again transported by the same company to various points to be put into circulation.