254 REPORT — 1861. 



form, and unsuitableness for shells. Sir William Armstrong uses a compound 

 projectile, formed of an iron case surrounded with a leaden coating — the rifling 

 being eftected by the force of the explosion in the barrel, which is thus partly ex- 

 pended in forcing the lead through the grooves. Mr. Whitworth uses a simple 

 hard-metal projectile, made of the requisite shape to fit the rifled bore by machine 

 labour in the manufactory ; so that the whole force of the explosion is employed to 

 propel the projectile. After gi'ving a description of the two projectiles, and point- 

 ing out that the Annstrong projectile necessarily required a breech-loading cannon, 

 and that the Whitworth is used at pleasure for muzzle-loading or breech-loading 

 cannon, Mr. Aston proceeded to notice the external shape of the projectiles. The 

 importance of giving to ships intended for high speed the shape best suited to 

 facilitate their progress though water is now universally acknowledged ; and Mr. 

 Whitworth considered that it was necessary to ascertain, by reasoning upon similar 

 grounds, and by experimental research, what was the proper shape to give to his 

 projectile, so that it might be propelled through the air under conditions most 

 favourable to precision and range. He, after numerous corroborating experiments, 

 decided that the projectile of the form exhibited to the Meeting was the best. It 

 has a taper front, having nearly the external section of what mathematicians term 

 the solid of least resistance, the curve being somewhat rounded ; the rear is made 

 to taper in such proportion that the air displaced by the front is allowed readily 

 to close in behind upon the inclined surfaces of the rear part. The middle part is 

 left parallel to the required distance, to provide rifling surfaces and obviate windage. 

 The results of long and repeated trials show that this form of projectile gives much 

 greater precision and a superiority of range, varying from 15 to 25 and 30 per cent, 

 (according to the elevation and consequent length of range), as compared with a 

 projectile of the common rounded front and parallel rear end. At low elevations, 

 where the range is comparatively short and the velocities great, the difference in 

 the result of the taper and non-taper rear is not so marked as at the higher eleva- 

 tions, where the mean velocities of the projectiles are reduced. But at all ranges 

 the superiority exists both in precision and velocity, as the elongated projectile at 

 no practical range has a mean velocity so great as to prevent the atmosphere 

 closmg in behind it. One of the most important advantages attending the use of 

 the taper rear is, that it gives a lower trajectoiy, which renders errors in judging 

 distance of minor importance, as the projectile which skims along near to the 

 ground is more likely to hit a mark, especially a moving one, than a projectile 

 which, moving in a more curved path, has to drop, as it were, upon the object 

 aimed at, whose distance therefore must be accurately guessed. The taper shape 

 of the rear is pecidiarly well adapted for the proper lubrication of the gun, which 

 is most essential for good shooting. W^ith the Whitworth gun a wad made wholly 

 of lubricating material was introduced; it obviates the necessity of washing out 

 the piece, — and the subsequent adoption of a similar wad for the Armstrong gun 

 enabled that piece also to be used ^uthout washing out, which was at first necessaiy 

 and foimd to oe a very inconvenient operation for a service gun. Various forms 

 of elongated Whitworth projectiles suited for special pui-poses were described : 

 tubidar projectiles for cutting cores out of soft materials, as the sides of timber 

 ships ; flat-fronted hardened projectiles, first used by Whitworth and afterwards by 

 Armstrong, for penetrating iron plates. It is found that these projectiles penetrate, 

 when fired point blank, through iron plates inclined at an angle of 57^° to the 

 perpendicular. The edge of the flat front, though slightly rounded, takes a hold, 

 as it were, as soon as it touches the plate, and the resistance met is merely that due 

 to the thickness of plate measured diagonally. Official experimental trials made 

 on board the ' Excellent,' at Portsmouth showed that these projectiles penetrate 

 readily through water, and would go through a ship's side below water-mark. 

 The new American floating battery, which is submerged to protect her sides during 

 action, would find no defence in that plan against these projectiles. Shell and 

 shrapnel hav-ing the elongated form and taper rear were also described ; and to 

 show the suitableness of that form for ricochet firing, tables were read, from which 

 it appears that the mean results of a series of six shots, making many ricochets 

 within a range of 2400 yards, gave the greatest mean deviation of about 75 j-ards 

 from the straight line. In considering the probable result of the contest now going 

 on between armour-plates and projectiles, it should be borne in mind that the limit 



