including breech mechanism, 271 inches; length of bore in front of gas
check, 30 calibers; powder space in chamber, 3,109 cubic inches;
charge, 100 pounds. The tube extends back to breech recess from
muzzle, in one solid piece. The breech block is carried in the jacket,
the thread cut in the rear portion of the jacket. The jacket extends
forward and is shrunk over the tube about 87½ inches. The re-enforce
is strengthened by two rows of steel hoops; the trunnion hoops form
one of the outer layers. In front of the jacket a single row of hoops
is shrunk on the tube and extends toward the muzzle, leaving 91 inches
of the muzzle end of the tube unhooped. The second row of hoops is
shrunk on forward of the trunnion hoops for a length of 38 inches to
strengthen the gun, and the hoop portion forms three conical frustums.
The elastic resistance of the gun to tangential rupture over the
powder chamber is computed by Claverino and kindred formulas to be
54,000 lb. per square inch.

[Illustration: THE ARMY 8 INCH STEEL GUN WITH CARRIAGE.]

The breech mechanism is modeled after the De Bange system. The block
has three smooth and three threaded sectors, and is locked in place by
one-sixth of a turn of a block, and secured by the eccentric end of a
heavy lever, which revolves into a cut made in the rear breech of the
gun. The gas check consists of a pad made of two steel plates or cups,
between which is a pad of asbestos and mutton suet formed under heavy
pressure. The rifling consists of narrow grooves and bands, 45 of
each. The depth of the groove is six one-hundredths of an inch.

Although the gun is designed for a charge of 100 pounds, it is
believed that it can be increased to 105 pounds without giving
dangerous pressure, and the intention is to increase the charge to