214 
MINUTES OF PROCEEDINGS OF 
perforating an iron plate than a f " and a 1" punching surface, in the ratio 
of 1*6 to 1; and similarly, that a punch graduated from J" to 1" and 
diameter is less effective for perforating a plate than a plain flat-ended 
punch, in the ratio of 1* to 1*16. 
This agrees with the result obtained at Shoeburyness from the impact of 
stepped shot, as they were found to have less penetrative power than plain 
flat-ended shot; the flat-ended shot from a wall-piece penetrated a plate 
at 25 yds. range, whilst the shot with one step only made a mean indent of 
0‘46", and the shot with two steps an indent of Q'Qh". 
The following is an extract from the report on an experiment which was 
made in December 1862 :— 
“ It seems to the Committee that the conical-ended shot did more injury to the plate, 
and suffered less, than any of the other forms submitted to them by Mr Makin. The 
cylinder with the front end slightly concave, was crushed out so much as to offer a 
much greater bearing surface on striking, and thus to hinder penetration on impact.” 
In an experiment made with experimental shot in March 1862, the report 
states: 
“ As regards the form of the shot, the remarkable effect of the shot in the 8th 
round, which had a conical end, as compared with those produced by flat-ends, leads 
the Committee to a preference of the former.” 
This shot, which weighed 99J lbs., and was fired from an Armstrong 7*" 
B. L. rifled gun with 14 lbs. of powder, broke a hole through the armour 
plate of a tc Warrior ” target, and the record of the experiment states :— 
“The shot ‘set up 5 T2", and the shoulder was broken off round the entire 
circumference, but it was otherwise uninjured.” 
Bigs. 10 and 11 will give an idea of the greater distortion of the flat- 
ended shot, and Big. 11 shows how slight was the alteration of form in 
Fig. 10. Fig. 11. 
the case of the conical-ended shot. This experiment clearly indicated the 
proper form for penetration; the shoulder, which originally existed, and 
which only impeded penetration, was sheared off on impact, and the shot was 
thus reduced to a plain cylinder with a conical end. 
In the experiment with 12-pr. experimental projectiles, which took place in 
November 1863, a comparison of flat-ended with round-ended shot was 
obtained. The mean “■ set up ” of the shot was as follows, after they had 
performed an equal amount of work :—- „ 
Bound-ended . O’3 9. 
Blat-ended.. 0T4. 
And as the report says,— 
" The round-ended thus showed the least alteration in form.” 
