THE ROYAL ARTILLERY INSTITUTION. 
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but also difficult of rapid production on a large scale, and besides there 
is no promise of superiority to justify any special efforts in this direction 
at present. Beautiful chilled projectiles have been supplied from 
Finspon in Sweden. The processes of manufacture are not fully 
known to us probably. The iron is softer than ours, the shot bear the 
marks of a cutting tool all over them. I believe that projectiles quite as 
good or even better can now be manufactured in the Royal Laboratory 
at about half the price charged for the Swedish shot as delivered. I 
do not say that all our service projectiles have been so good. As perhaps 
most officers present are aware, there have been manufacturing diffi¬ 
culties which have led to the condemnation of considerable numbers of 
projectiles; but I believe these are now overcome, and I feel sure that 
we may place great confidence in the mechanical talent and ability of 
all the hands to whom the work of our manufacture is entrusted. As 
to our future issues, the Ridsdale iron supplied from Elswick seems to 
promise even better results than the iron we have employed up to this 
time. 
I should like for a few moments to consider the action of shot on 
impact against armour. The powers of a projectile are generally 
estimated— 
1st. By the actual penetration in the plate. 
2nd. By its own behaviour; that is whether it stands up well to its 
work or breaks away. 
The first mentioned test is plain and fair where calibres and charges 
are the same. The second indication is less distinct; the supposition 
is that when a shot shivers, the fragments commonly carry away in them 
a certain part of the work stored up in the projectile, which part clearly 
becomes unprofitable, except in the case of complete penetration. It is 
to be noticed however that the target is the agent by which the shot is 
broken, and the actual work of fracture is bond fide reaction of ivorlc 
impressed on the target as truly as the setting up a shot; in fact a shot 
may be so fractured that before the fragments separate from the head, 
they have lent nearly all their striking power to the work : only while 
in this case we may say that we cannot quite estimate how little work 
was carried off in an unprofitable form, in the case of a shot which 
remains entire we are sure that none at all has been so wasted. May 
I call your attention to the 9-inch Finspon Palliser shot before you, 
which penetrated 14 ins. into solid iron plate and bounded back several 
feet, slightly set up and cracked but intact. In the case of complete 
penetration, when of course the penetrative powers are not taxed to the 
full, it is rather an advantage for a shot to break as it comes through. 
Perhaps while on the subject of penetration of armour, it may not be 
wasting our time to consider a few statements concerning flight and 
penetration which have been made by those who have specially studied 
these questions. 
Lieut. Sladen on Resistance of the Air. 
Lieut. Sladen, after taking part in Professor Bashforth's investigations 
as to the resistance of the air, by means of the professor's chronograph, 
remarks that, in addition to the pressure on the head there is a powerful 
