116 ANNXTAL OP SCIENTIFIC DISCOVERY. 



ner. Out of twenty-four shots, twelve were of this character. Not 

 one of them passed throuirli th(^ t:ir_2;et, and every one was either 

 broken into fragments or bul;i^ed out of shape. 



The Palliser chilled shots in every case penetrated the ii'on plate, 

 and in one instance, on the square face of the target, went en- 

 tirely through plate, backing, and hning, and lodged in a pile of 

 iron plating, brick, and stone masonry, twelve feet in the rear of 

 the target. In no instance was the form of the shot changed. The 

 Palliser shots and shells have heads formed on a radius of one and 

 a half diamet(>rs of th(! cylindrieal jiortion. AVhenever the Palliser 

 shots struck the inclined face of the target they penetrated, while 

 the cast-steel shots sometimes glanced off. 



One circumstance in this trial is remarkable. The steel shots 

 "wei-e so hot after striking the target that tliey could not be handled, 

 while the eliilled shots were barely warm. This, witli the fact of 

 the change of form in the steel projectiles, proves that much of the 

 energy of the shot had been expended in this direction, instead of 

 in iienetration. 



While the velocity of the shots fired in our Fortress Monroe 

 experiments exceeded in no instance 1,155 feet per second, that 

 of those in this Shoeburyness trial ranged from 1,2G0 to i,340 feet 

 per second. At such an initial velocity, with a distance of only 

 two hundred yards l)etween the gun and target, it ceases to be 

 very surprising that it was possible to throw shot thi'ough such a 

 barrier. — Scientific American. 



FENETRATIOX OF SHOT, AND RESISTANCE OF IRONCLAD 



DEFENCES. 



Captain Noble has lately caiTied out a series of experiments 

 under the direction of the Ordnance Select Committee, for the 

 purpose of determining various i)c)ints connected with the i*esist- 

 ance of iron plates, and his paper forms part of a report which 

 he has submitted to the committee. 



The above series of experiments were instituted for the purpose 

 of determining the foliowing points : 1st, To determine the rela- 

 tive penetrating effects of two steel shots on an iron plate, pro- 

 vided they strike with the same "work" or mechanical effect, 

 notwithstanding the one may be heavy, with a low velocity, and 

 the other light, with a high velocity. 2d, To determine the rela- 

 tive resistances of a jjlate to penetration, by two steel shot of 

 similar form of head, and striking with " work " proportional to 

 their respective diameters. In order to determine the first point, 

 the committee fired a number of hemispherical-headed steel shot 

 from a muzzle-loading gun of 6.3-inch calibre, at 4^ and 5i-inch 

 unbacked plates, the weights of the shot being different, viz., 

 35 lbs., 70 lbs., 106 l])s., and the diameters the same, viz., 6.22 

 inches. The charges with which these projectiles Avere fired 

 were arranged so that the " work" was the same in each case, — 

 that is to say, the velocity on impact of the light shot was much 

 gi'eater than that of the heavy shot, while the expression W v^, 

 weigiit of shot multii)lied by the square of its velocity, was con- 



