Page:Popular Science Monthly Volume 51.djvu/169

Rh of five and a half miles, and it pierces through armor a yard thick at a distance of a mile and a quarter. Another rifle, twenty-eight centimetres (eleven inches) in caliber and forty calibers (thirty-seven feet) in length, when elevated forty degrees sends a seven hundred and sixty pound projectile over twelve and a half miles. This is the distance from the Battery to Fordham in New York city. The shot reaches an extreme height of a trifle over four miles. It could thus be easily made to clear the highest mountain peak in North America.

The power of endurance of a gun diminishes rapidly with increase of projectile power. The life of the American twelve-inch rifle has been given as only five hundred or six hundred rounds, while a field gun of modern make may be fired thousands of times if used with reasonable care. Within the next two years a new rifle of sixteen-inch caliber will be constructed at Watervliet. This is nearly equal in size to the monster Krupp gun at Chicago. Such immense guns can be employed only for seacoast defense. In handling them complex machinery is necessary, not only for moving and adjusting the gun but for loading it. No group of soldiers could without machinery lift and put into place a projectile weighing a ton. It seems doubtful whether any real advantage can be gained by going beyond the limits of size already



reached. The difficulty at present is not confined to that of manipulation, but extends to the quality of the forgings made on so large a scale. Krupp makes his guns entirely of "crucible" steel, such as is employed for cutlery. Made by this method, steel is indeed the most uniform in composition, but nowhere outside of the Krupp works has it been manufactured on a scale large enough for great gun forgings. In France, in England, and in America, the "open-hearth" process is depended