as
it were, one extended apartment. In this are placed hundreds of forges,
furnaces, trip-hammers, rolling-mills, dropping-machines, and
trimming-machines,--besides scores of sledge-hammers, wielded by
stalwart arms. The noise here is so great that no effort of the voice
avails to make itself heard, and I doubt if even the loudest thunder
would make any appreciable addition to the general clangor. Small iron
carts, filled with hot iron, are incessantly whirling around you;
red-hot sparks, or melting drops of iron, are flying about the room in
all directions; the air is hot to suffocation, and sulphurous from the
burning of bituminous coal; while hundreds of swarthy faces, begrimed
with grease and dirt, are dripping with sweat: so that you can scarce
avoid the suspicion that you have at last stumbled into the infernal
regions, and are constantly wondering why some of Pluto's imps do not
seize you and plunge you into some horrible furnace, or chop you up
under a trip-hammer.

Having survived the examination of this department, you follow your
guide from the forging-room down a winding flight of iron steps to the
water-wheels, which are situated forty feet under ground. These wheels
are so arranged that they can be run together or separately; they are
generally run together, and in connection with the immense low-pressure
engine.

After the barrels are bored, turned, milled, and straightened, they are
next to be polished. For this purpose they are placed in upright frames,
each frame containing five barrels. The polishing is done by means of
hard, wooden rubbers, provided with a plentiful supply of lard-oil and
emery. The rubbers are placed horizontally, with their grooved ends
pressing by means of springs against the barrels, which are drawn
between them by a very regular and rapid vertical motion. The barrels
are also turned around slowly and continuously by a lateral movement,
which insures a uniform polish. They are allowed to remain in the first
polishing-machines fifteen minutes, and are then placed in a similar
machine and go through a second polishing, differing from the first
simply in the absence of the pulverized emery,--oil only being used upon
the rubbers during this finishing operation. The musket is now
completed, with the exception of the rifling, and some slight polishing
to be done by hand at the muzzle and breech.

Two polishing-machines are used for ramrods, similar in construction to
those above d