and is capped with dressed stone to receive the bed-plates.

_The Power-Hammer_ (Figs. A and B).--The power-hammer, properly
so-called, consists, in addition to the hammer-head, of two standards to
whose inner sides are bolted guides upon which slides the moving mass.
The bed-plates of cast iron are 28 inches thick, and are independent of
the anvil-stock. They are set into the bed of dressed stone capping the
foundation, and are connected together by bars of iron and affixed to
the masonry by foundation bolts. To these bedplates are affixed the
standards by means of bolts and keys. The two standards are connected
together by iron plates four inches in thickness, which are set into the
metal and bolted to it so as to secure the utmost strength and solidity.
The platform which connects the upper extremities of the standards
supports the steam cylinder and the apparatus for distributing the
steam. The latter consists of a throttle valve, twelve inches in
diameter, and an eduction valve eighteen inches in diameter, the
maneuvering of which is done by means of rods extending down to a
platform upon which the engineman stands. This platform is so situated
that all orders can be distinctly heard by the engineman, and so that
he shall be protected from the heat radiated by the steel that is
being forged. All the maneuvers of the hammers are effected with most
wonderful facility and with the greatest precision.

The piston is of cast-steel, and the rod is of iron, 12 inches in
diameter. The waste steam is carried out of the mill by a pipe, and,
before being allowed to escape into the atmosphere, is directed into an
expansion pipe which it penetrates from bottom to top. Here a portion of
the water condenses and flows off, and the steam then escapes into
the open air with a greatly diminished pressure. The object of this
arrangement is to diminish to a considerable extent the shocks and