p. 12 | HOW CANNONS ARE MADE

International Tract and Missionary Society · Oakland, California · Nov 18, 1889

FromSigns of the Times, Vol. 15, No. 44.

HOW CANNONS ARE MADE.

At last the cannon is turned down, and is ready to be bored inside. In this operation it must be bored so straight and true that the boring tool, entering at the exact center of the small end of the cannon, will come out precisely at the center of the large end, seventeen feet away. Those of you who have tried to bore a straight hole lengthwise through even a short bit of wood will know that this work requires not a little skill and care.

When any of you boys have a job of boring to do at your work-bench, you make fast the article to be bored and turn the boring-tool. It is just the other way in boring a cannon. The boring-tool, or "bit," is held firm and motionless, while the great mass of steel to be bored turns around. This plan is found to insure steadiness of the bit. It would be almost impossible to make this bit firm and solid enough to do its difficult work, and yet free to turn around in the cannon. So if you had been at the side of this gun lathe when the work was begun, you would have seen that the bit was motionless—except for a slow advance into the gun.

The bit attends strictly to business, and steadily bores its way through the steel. Most of you have been to the country and have seen a pig "rooting" in the ground. Imagine, then, the pig to be standing still and the ground to be slowly passing under the pig's snout and being "rooted," and you will have a case much like that of the bit and the cannon. In fact, the boring-tool is called a "hog-nosed" bit, and it roots up that cannon as if it enjoyed the operation. No long, graceful curls come from this boring, but small, crisp shavings that are removed as fast as they accumulate, in order that the boring-tool's work shall not be interfered with. The bit is going into the steel at the rate of three-eighths of an inch for every turn of the cannon, and it is making a round hole almost large enough for a boy to put his head in—five and three-quarters inches in diameter. As the round hole grows deeper, the heavy bar, on which the bit is fastened, advances into the cannon steadily, moved by a number of wheels and screws that form part of the lathe.

I must not lose sight of the shavings, the little ones that come from the inside, and the long, spirally-twisted ones that are turned from the outside of the cannon. A military-looking man, standing near the lathe, does not lose sight of these shavings or trimmings, either. This man's business is to carefully inspect the borings and trimmings. That is what he is paid to do. Uncle Sam pays him, and expects him to earn his salary. The cannon is being made for Uncle Sam, and he intends to find out all its qualities, whether good or bad. So the man eyes the borings carefully. Now, if with a plane, or your knife-blade, you will cut a thin shaving from a bit of wood, it will show any little flaw existing in the wood from which it was sliced. The tiniest knot-hole or crack will show in the shaving much more plainly than in the wood itself. So it is with a cannon's shaving. It is a dreadful tell-tale, and the fault-finding man beside the gun knows this perfectly well. He examines the spiral turning, or the little piece of boring, and finds no evidence of a flaw or crack. The long, spiral strip is as smooth as glass, and as glossy as your sister's curls.

Into the solid steel the hog-nosed bit roots its way, until it is in so far that a little electric light must bear it company, to show the workmen how matters are progressing in the heart of the cannon. After eighteen days of steady boring, the bit lets daylight into the bore of the cannon by emerging at the other (or larger) end, seventeen feet away.—St. Nicholas.