426 



TRANSACTIONS OF THE AMERICAN INSTITUTE. 



rest upon the lands of the gnn, and which 

 compel the forward part of the projectile, 

 though smaller than the bore, to maintain a 

 central position therein. The next figures 

 are a front view and a side view of another 

 form of projectile, intended to operate 

 against iron armor, at short ranges. It is 

 solid throughout, and diflers but little from 

 the long range projectile described, except 

 that it has not the hollow rear — it is cored 

 and filled with a screw bolt C, in the center, 

 as already described. 



The next four figures are an elevation, and to secure uniformity in the 

 casting, a section of a hollow shell with a rounded front, and a cross 

 ^ section of the same on the line 



SE. This shell is provided with 

 thirteen plungers aa, etc., adapted to 

 }W explode by concussion. These radiate 

 in so many directions, that some one 

 may explode if the shell strikes in anj'- 

 position. A time primer is added, when 

 it is required that the shell shall pene- 

 trate before explosion. This shell is 

 adapted to be thrown inside of forts on 

 elevated positions, or into cities, where 

 from the height of the trajectory, it has 

 been heretofore difficult ta insure the 

 explosion of percussion shells. It will 

 usually explode upon striking, if it 

 is tumbling end over end, and on 

 striking in any position, except- 

 that of a fair blow with its rear end. Another kind of shell is 

 shown, and the figures are a side view and a front view of 

 a projectile intended to act as a time shell, and which is 

 adapted to receive an ordinary or any improved form of 

 time fuse. This shell is constructed according to the theory 

 hereinbefore stated, and the greater weight 

 in the forward part of this projectile, when 

 the cavity M is filled with powder alone, is 

 very marked, while the greater displace- 

 ment of the rear portion of the shell, and 

 the boutons to steady the small front portion 

 in the gun, are like the projectiles previously described. 



AN ACCELERATING GUN. 



The attainment of a very long range, or the penetration of iron armor, 

 requires the highest velocity possible to be attained. To meet this neces- 

 sity I have provided a gun, in which the length of the gun is proportioned 

 to the size of an enlarged chamber that contains the powder, from which 

 is evolved a sufficient quantity of gas to keep a high expansive force 



