110 ANNUAL OF SCIENTIFIC DISCOVERY. 



ounces ; recoil, 6 feet 4 inches ; flight, 3 seconds ; range, 879 

 yards; deflection, 1.6 yards; velocity, 1,037 feet per second. 



"Round No. 9 : Charge, 35 pounds; shot, 452 pounds 8 

 ounces; recoil, 6 feet 7 inches; flight, 2.8 seconds; range. 880 

 yards; in line, true ; velocity, 1,044 feet per second. 



"Round No. 10: Charge 35 pounds; shot, 450 pounds; re- 

 coil, 6 feet 5 inches ; flight, 2.9 seconds ; range, 873 yards ; deflec- 

 tion, 1 yard, left; velocity, 1,010 feet per second.. 



"Round No. 11: Charge, 50 pounds; shot, 453 pounds; re- 

 coil, 9 feet 4 inches; flight, 3.1 seconds; range, 1,023 yards; m 

 line, hit the target near the centre; velocity, 1,191 feet per 

 second. 



"Round No. 12 : Charge, 50 pounds; shot, 451 pounds 8 

 ounces ; recoil, 9 feet 9 inches ; flight, 3.2 seconds ; range, 1,073 

 yards; deflection, 2.2 left; velocity, 1,211 feet per second. 



"Round No. 13 : Charge, 50 pounds; shot, 451 pounds 8 

 ounces; recoil, 9 feet 10 inches ;' flight, 3.2 seconds; range, 1,140 

 yards ; deflection, 2.4 j-ards left ; velocity, 1,214 feet per second. 



" The two concluding rounds were fired with American mam- 

 moth powder. 



"Round No. 14: Charge, 60 pounds; shot, 451 pounds 8 

 ounces; recoil, 9 feet 10 inches ; flight, 3.1 seconds; range, 1,012 

 yards ; in line, true ; velocity, 1,194 feet per second. 



"Round No. 15: Charge, 60 pounds; shot, 452 pounds 8 

 ounces; recoil, 9 feet 9 inches; flight, 3.1 seconds; range, 1,032 

 yards; deflection, 2.6 left; velocity, 1,210 feet per second. 



" The alteration from right to left deflection was possibly caused 

 by a change in the direction of the wind. 



" We cannot in this notice enter into detailed comparisons be- 

 tween the performances of our own heavy rifled guns and this 

 American cannon; but we may briefly add that the battering 

 charge of our 9-inch Woolwich muzzle-loader is 43 pounds L.G.R. 

 powder, and the ordinai-y service charge, 35 pounds. The weight 

 of the 9-inch rifle shot, 250 pounds. 



"The American Rodman has thrown its shot very true and a 

 very long distance." 



AMERICAN VS. ENGLISH GUNS. 



It is much to be wished that the real power of the heavy 15-inch 

 and 20-inch guns were understood in this country, instead of our 

 believing so generally in their "low velocities." In the large 

 chambers of these guns the powder gas has additional room for 

 expansion, and, as would be the case with steam cut off at a small 

 portion of the length of a large steam cylinder, it thus does more 

 work. In reality, while the dynamic value of our cannon powder, 

 for each pound weight, is but about 170,000 foot pounds, that of 

 no better powder, fired in the large-bore American guns, is 200,- 

 000 foot pounds. Thus, the 15-inch gun, fired with 60 pounds of 

 powder and a 440 pound shot, has an initial velocity of 1,320 feet 

 per second, a rate which would certainly not be considered slow 

 by our own ordnance engineers. Our system of small bores and 



