1871.] Modem British Ordnance and Ammunition. 525 



gained ; the 25 -ton and other similar guns are therefore 

 relatively far less powerful than guns of twenty years back, 

 possessing neither the relative range nor relative penetrating 

 power of the old 32-pounder of 56 cwts." 



Now, according to Captain Noble and Captain Stoney, 

 gun-power is* properly estimated by calculating the dyna- 

 mical force (vis-viva, or energy) of the projectile at various 

 ranges, in foot-tons ; whilst the comparative penetrative 

 effect by dividing the vis-viva by the diameter of the shot ; 

 from this it is found that the 12 -inch gun can deliver a blow 

 at 1000 yards range twelve times as severe as the 68-pounder 

 smooth-bore (95 cwts.), whilst as regards their relative 

 power of perforation, the 12-inch gun is eight times as 

 powerful as the 68-pounder. 



By recent experiments it was found that our 10-inch guns of 

 18 tons penetrated 15 inches of iron (in three 5-inch plates), 

 upon which the 15-inch Rodman smooth-bore American 

 gun of 20 tons only made a shallow indent. 



Captain Sharpe's expanding carriage is ingenious, but not 

 to be compared with Captain Moncrieff's, whilst it seems 

 doubtful if his proposed winged-shot are theoretically or 

 practically possessed of the advantages claimed for them ; 

 indeed, the inventor would appear to be desirous of giving 

 up the rifling principle and returning to the old smooth- 

 bores, when he says, p. 23, " Striking the wings obliquely 

 gives a rotary motion to the shot (should such motion be 

 required)." 



Our present service Palliser-shells at present meet nearly 

 all practical requirements, and when fired with full battery 

 charges at 200 yards range, are calculated to perforate iron 

 plates of a thickness of 1 inch greater than their diameter.t 

 A few facts about these shell may not be uninteresting ; 

 first, as to their shape, which is cylindro-conoidal. It has 

 been found that for accurate shooting a length of at least 

 two calibres is necessary, but of course this varies im- 

 mensely; thus the double shell of a 7-inch gun is 27*2 inches, 

 i.e., all but four calibres ; after many experiments as to the 

 best form for the head of the projectile, it has been decided 

 nearly conclusively that an ogival head struck with a 

 radius of ij diameters is the best adapted both for flight 

 and penetration. It has also been found that shot fly better 

 when hollow than when solid, the weight when distributed 

 further from the axis giving a longer radius of gyration. 



* Royal Artillery Institution Paper, vol. vi., p. 116 et seq. 

 f See Captain Orde Browne's Treatise on Ammunition for Rifled 

 Ordnance, p. 215. 



