158 POPULAR SCIENCE MONTHLY. 



experiments were made before a successful breech-loading mech- 

 anism was perfected. An explanation of either of the two modern 

 systems would be beyond the scope of the present discussion. It 



i 



TWELVE-INCH RIFLE, WITH BREECH-LOADING MECHANISM CLOSED. 



may be sufficient to say that the system in use in America is sub- 

 stantially that of tne French, an interrupted screw which fits into 

 the breech and is provided with an efficient gas check. This is so 

 constructed that the mere fact of explosion tightens the gas check 

 and effectually prevents the escape of hot gas between the threads 

 of the screw. 



The largest and most celebrated gun factory in the world is 

 that of Krupp, at Essen in Germany, near the Belgian border. 

 Besides monopolizing the construction of guns for the German 

 Government, this factory has supplied a great number to most of 

 the leading powers of Europe. It was established in 1818, and 

 from the very outset attention was concentrated upon the making 

 of steel. The first finished piece of artillery in cast steel was made 

 in 1847. This was a small field gun capable of projecting a ball 

 of only three pounds. The manufacture of steel at these works 

 has since been so perfected that Krupp can now be scarcely said 

 to have an acknowledged rival in the world. His magnificent 

 display at the Chicago Exposition was seen and admired by many 

 thousands of visitors. Among these exhibits was a steel rifle 

 forty-two centimetres (16*54 inches) in caliber, and thirty-three 

 calibers (forty-six feet) in length. Its weight is one hundred and 

 twenty tons, or a little more than double that of the twelve-inch 

 rifle at Watervliet. With a charge of nine hundred pounds of 

 powder it gives an initial velocity of two thousand feet per second 

 to a projectile weighing twenty- two hundred pounds, whose ini- 

 tial energy is thus sixty thousand foot tons. When fired at an 

 elevation of about eleven degrees it sends this projectile to a dis- 



