Page:Popular Science Monthly Volume 51.djvu/165

Rh as development in ordnance was concerned. Our coast defenses continued to be provided with, nothing better than the Parrott rifles and smooth-bore Rodman guns which had been in use during the war. Meanwhile there had been great progress in Europe, particularly in France and Germany. In 1885 a commission appointed by Congress reported the necessity for heavy expenditure of money in order that this country be put into a condition of reasonable readiness to repel foreign invasion. During the last ten years appropriations to the amount of twenty million dollars have been made to meet these needs, and the work of rehabilitation is now well started.

The rifled gun of to-day, as finished at the Watervliet Arsenal, is constructed almost wholly of steel. This is of the best quality that can be produced on a large scale in American foundries. It is made by the "open-hearth" process, for the most part at Mid-vale and Bethlehem in Pennsylvania. The forgings, after undergoing thorough official inspection and careful testing, are sent to the great gun shops at Watervliet. Here the various parts composing a gun are worked up, assembled together, and finished. Before assignment for government service each gun is subjected to a searching test, more severe than should reasonably be expected in actual use.

The largest gun thus far designed at Watervliet is a rifle of twelve-inch bore, forty feet in length, and fifty-seven tons in weight. From such a gun an elongated steel-pointed projectile, weighing one thousand pounds, or as much as an ordinary horse, is shot with a charge of five hundred and twenty pounds of powder. It receives an initial velocity of two thousand feet per second, and would penetrate through rather more than two feet of steel armor plate put in front of the muzzle. If shot into the air at the proper elevation it would pass over a range of nearly nine miles. Such a missile, thus fired from the lower end of New York city, would pass over Central Park into the district beyond Harlem River. This range would be covered so quickly that the shot would reach its destination several seconds before the sound of the explosion is heard at the same point. The initial energy of the projectile would be sufficient to lift a weight of twenty-seven thousand tons through a height of one foot. If this weight were that of a spherical mass of gold, the heaviest popularly known metal, its diameter would be nearly forty-six feet, and its value eighteen billion dollars. This is more than a dozen times the value of the total gold production of the world during the last twenty years.

The cost of such a gun is about sixty thousand dollars; that of the charge of powder, one hundred and seventy-five dollars; of the armor-piercing projectile, three hundred and fifty dollars.