ARTILLERY 243 



Mr. Wliitworth and his admirers have constantly. nssertod that his small-bore gives 

 a flatter trajectory than the larger bores chosen by Armstrong, Britten, and others; 

 This is, however^ not the case under all circumstances, and arose partly from the fact 

 of the Wliitworth guns first tried being fired with charges of ith of the weight of the 

 projectile, whereas the greater number of other rifled guns used charges of only ith of 

 i'jjth. Mr. Whitworth is quite right to use as large a charge, as he. can, but it must be 

 taken into account in drawing comparisons. In practice from two rifled guns of different 

 calibres, but firing projectiles of the same weight with equal charges, the large bore 

 will give a lower trajectory'; but as the projectile with the smaller diameter is less 

 retarded, its trajectory will gradually become lower, as compared with the other, 

 until beyond a certain range th'e small bore will give the lower trajectory. Small 

 bores have found little favour on ]the Continent, and it is for the authorities to demand 

 either a largo or a small bore as circumstances may require. 



The following conditions are requisite in any rifled gun to ensure accuracy of 

 fire: a rotatory motion must be given to the projectile round an axis parallel to, : 

 or coincident with, that of the bore ; and the velocity of rotation imparted to tho 

 projectile must bo sufficient to counteract tho pressure of air tending to turn tho shot' 

 over or render it unsteady in flight. 



Great numbers of rifled guns with projectiles to correspond have been proposed,' 

 but most of tho systems of rifling that have been adopted by any service, or tried on 

 the practice-ground, may be divided into the following classes : 



(1.) Muzzle- or breech-loading guns, having projectiles of iron fitting the peculiar 

 form of the bore mechanically. ' 



(2.) Muzzle-loading guns, with projectiles having soft-metal studs or ribs to fit thff 

 grooves.. , . ..- ...--, ..; 



(3.) Muzzle-loading guns, with projectiles having a soft-metal envelope, coating, or 

 cup, which is expanded by the gas in tho bore. 



(4.) Breech-loading guns, with projectiles having a soft-metal coating larger in 

 diameter than the bore, but which is compressed by the gas to the form of the bore. 



The effects of those guns, and consequently their relative values, will bo best shown 

 by extracting from the ' Proceedings of the Royal Artillery Institution ' some of the 

 results ag officially stated by the officers in charge of the experiments. The more 

 important of the targets have been selected, as representing the actual conditions of 

 qiir ships at th,e time (1868), and of the power which. can be brought to bear upon 

 the armour-clad ships of an enemy. 



:; ' A . .- 



'Warrior' Target. 



This target was 10. feet by 12 feet, consisted of three plates, made at the Park Head 

 forge, all 4 inches thick, and varying from 12 feet by 3 feet to 12 feet by 3 feet 

 4 inches. 



The Horsfall gun used weighed 24 tons 3 qrs. 2 Ibs., diameter of bore 13-014 inches, 

 diameter of shot 12-8 inches. It was first fired at 200 yards' range, with a solid 

 cast-iron shot, weighing 279 Ibs. and a charge of powder 74'40 Ibs., which gave an 

 initial velocity of 1,630 feet, reduced at 40 yards to about 1,610 feet per second. 



The shot completely pierced the target through and through, making an irregular 

 hole in the armour 2 feet square, and cracking but not buckling it. 



From this and other .similar experiments it appeared that the ' Warrior ' ship at 

 200 yards would be completely pierced by the Horsfall shot. A solid shot of an- 

 nealed cast-iron weighing 285 Ibs. was fired at tho same target with the same charge 

 as before, from a range of 800 yards. This grazed the ground 17 yards short, and 

 struck the target in the junction of two . plates, breaking a large hole about 2 feet 

 square through the armour, and burying itself in the timber backing. This provea 

 that at 800 yards the real ' Warrior ' would bo severely injured, but the skin would 

 not be penetrated by an individual shot. 



Mr. Whitworth made a series of experiments to prove the penetration of his pro- 

 jectiles. The shot and shell were fired from a 12-pounder breech-loader, a 70-pounder 

 muzzle-loader, and a 120-poundor muzzle-loader. Most of the shot and shell pierced 

 the target ; the following were the more remarkable results. A target was made in the 

 form of a box, with the object of putting to the test Mr. Whitworth's boast that -he 

 could drive a shell through tho side of. an armour-clad ship, and make it burst 

 between decks. The shell fired on this occasion, with an initial velocity of 1,275 

 feet, passed completely through- the 4-inch armour-plate and its oak backing, and ex- 

 ploded on the rear side of tho box, the plate of which was indented 2 inches, bursting 

 the box and -blowing -all six sides outwards. 



A shell of homogeneous metal, weighing 127 Ibs,, with a bursting charge of 3 Ibs. 

 8 oz. and without a fuse, was fired at the same range with a- -charge of 25 Ibs. of 



