THE ROYAL ARTILLERY INSTITUTION. 
199 
68-Pounder. 
At 100 yds. range. Penetrated the plate and from 17 to 22 in. of timber, 
At 20 yds. Striking on a weak spot. Penetrated the side of the ship, pieces of shot and plate being 
found scattered on the deck. A second shot penetrated the plate and to a depth of about 10" into 
the timber. 
The Beport on this experiment states, “ It was found that there was no 
comparison between the effect of the two descriptions of shot, one 68 lb. 
shot doing as much damage to the plate, and more injury to the woodwork 
and frame of the ship, than five 32-pr. shot that had struck close together.” 
The space in which these shot struck was 2' 9" x 2' 8", and the report goes 
on to state, that, whilst the framework of the side under where the 32-pr. 
shot struck was “scarcely injured,” it was “much injured” under where 
the 68-pr. shot struck. 
The result of this experiment clearly shows the necessity for an alteration 
in the present armament of our coast batteries, which consists, mainly, of 
68-prs., 32-prs., and shell guns. 
With regard to the thickness of iron plate required to break up cast-iron 
shot, Captain Chads arrived at the following conclusions, from numerous 
experiments made at Portsmouth in 1854, at a range of 450 yds. 
(1) That both solid and hollow shot w r ould, under ordinary circumstances, 
pass through J and ftlis inch iron without breaking. 
(2) That under ordinary circumstances, solid shot will pass through f in. 
iron without breaking; that hollow shot, under similar circumstances, wall 
generally break up. 
(3) That under ordinary circumstances all shot (cast-iron) solid or hollow, 
wall break up in passing through ftlis inch iron. 
Captain Hewlett reported as follows on this subject, after carrying on 
experiments in 1862 with a 68-pr. S. B. gun. 
(1) That the shot breaks up when it strikes the fth plate with high 
velocity, and generally with medium velocities, but not when fired with the 
lowest charges. Those fired with 5 lbs. charges passed through the plate 
whole. 
(2) The shot that struck the -fgth. plate did not on any occasion break 
up, whether fired with a high or medium charge. 
(3) Plates intended to break up cast shot on impact, should never be less 
than fth" in thickness;. 
(4) The lowest charges break up shell on the latter striking either the 
fth or xgtli plates. 
The plan of using heavy shot at low velocities for attacking armour plates, 
had some advocates in this country a few years since. Sir W. Armstrong 
stated in his evidence before the Special Committee on Iron, that he thought 
“ a heavy shot at a low velocity would be most effectivethe late Captain 
Lyons, E.A. w r as also of this opinion. 
Shot of 200 lbs. weight were therefore manufactured for the 7" Arm¬ 
strong B. L. rifled gun, and were fired with a 10 lbs. charge at the original 
[vol. iv.] 26 
