Democratic Sentinel, Volume 7, Number 21, Rensselaer, Jasper County, 22 June 1883 — Making Steel Cannon. [ARTICLE]

Making Steel Cannon.

The manufacture of steel six-inch cannon at the Washington Navy Yard ordnance shops is thus described: The steel is first “turned” by a steam lathe working slowly, *but with tremendous power, until tiie heavy mass of “steel in the rough,” so to speak, becomes a long cylindrico-conoidal column. In this* condition it is placed in proper position, and a hole drilled clear through it by means of what is called a “hog bit.” This hog bit is a small rectangle of very hard steel, turned up at one end in such a manner as to form a rude vertical section of a spherical-tri-angle. The whole rectangular piece is then clamped down upon a flat shaft of chilled iron in such a manner as to fit in and form one piece with the shaft. The latter has at the opposite end a cylindrycal shape, which end is held in a frame and worked by appropriate machinery moved by steam upon one end of the steel column to be perforated. The end of the column' is first “dug into” a little, and then the “hog bit” does its work. It revolves on its axis and the “bit” describes a circle, tearing out the hard steel slowly but surely. As the guns have a bore of six inches diameter, and the bit describes a cirole of only two and three-quarters inches radius, the enlargement of the perforation is accomplished by other bits. Once perforated, the now hollow tubes of steel require to be “jacketed,* “collared” and “breeched” before it is allowed to graduate into the society of a cannon. The jacket is an outside wrap Of steel, hollowed in the same way, heated until it expands sufficiently to be slipped over the tube it is intended to jacket. Upon cooling this outside wrap contracts and presses upon the now inside tube with almost the same degree of cohesion as the molecules of the steel themselves. The object of the “jacket” is to strengthen the gun and prevent accident. Collars of steel, great blocks of carbonized iron, having been turned into shape and perforated, and next expanded by heat, are slipped over the breech part of the gun. When contracting they grow into and become a part of it. The breech head of the gun is next lathed and fashioned, different workmen being employed on different parts of this. The rifling of the gun is another step. A different kind of “bit” from the “hog;” a spur of steel tempered to great hardness is clamped to the center of a semicircular piece of copper and iron, and this last device is slowly worked through the gun on a spiral turn, giving the “rifle twist.” The breech head is then grooved and adjusted, and the breech cap formally adjusted. This, as is known to All who have examined breech-loaders, Swings back on ai hinge or spring, and when .closed is securely locked by a lever clamp, f