BIGGEST GUN IN THE WORLD.
The operation of shrinking a jacket on the sixteen-inch gun at the Watervliet Arsenal having been successfully performed, the great gun is being completed. The first attempt to jacket the tube was unsuccessful, the outer piece having stuck fast a few inches away from the point for which it was intended. The second attempt was successful in every particular. The gun when completed will be the most powerful piece of ordnance in the world, and will weigh, without the carriage, 126 tons. Its length will be forty-nine feet, six inches: the diameter of the breech, six feet, two inches; the size of the bore, sixteen inches. The theoretical range of the piece will be 20.76 miles: weight of projectile, 2,370 pounds. The projectile intended for the big gun is sixty-four inches long, and the powder charge consists of 1,060 pounds. The powder will cost $265, and the projectile $600, so that the cost of every discharge, exclusive of wear and tear on the gun and pay of people employed in its manipulation, will be $865. The projectile, with its initial velocity of 2,600 feet a second, will penetrate wrought iron to the depth of 41.6 inches. To attain its maximum range the projectile will reach an elevation of five miles, and the pressure on the gun at the time of its discharge will be thirty-six thousand pounds to the square inch. Although the gun is of monstrous proportions, it is put together with the nicety of a delicate instrument and the difference between the outside radius of the gun itself and the inside radius of the jacket which was shrunk on last week was only six one-hundredths of an inch after the jacket had been heated. The jacket weighing thirty tons, must be lifted while hot from the furnace and swung up over the gun and then lowered into place. “The slightest inequality in the heating,” said Colonel Farley, the ordnance officer in charge of the work, “an error of the smallest fraction of an inch in the measurements, and all these months of preparation will have been wasted, for once that jacket sticks,—that ends the effort. It can not be heated again and taken off. It must be cut off. Then the work must be done all over again.” It was necessary to construct new machinery to make this gun, a notable piece being a lathe 135 feet long, with a swing of nine feet.