THE ROYAL ARTILLERY INSTITUTION. 
71 
The charge of 53 lbs. of prismatic powder was now substituted for the 
46J lbs. of Prussian powder 1 2 —conditions vastly different, we need hardly 
observe, from those which the guns had been originally designed and proved 
to meet. 3 
The next point was the reduction of the lead jacket of the shot. Captain 
von Doppelmair argues at great length, and Mr. Krupp in his pamphlets 
is very emphatic in the same direction, to prove that the lead jacket of the 
shot is unfavourable to penetration. 3 We are disposed to admit the sound¬ 
ness of this reasoning, with this qualification—that as the lead coating adds 
to the weight of the projectile, it increases the vis viva of the shot, and must 
not therefore be altogether thrown out of the account. 4 5 But that a thick 
lead coating is to a very large extent unproductive in penetration trials, and 
actually obstructive of the passage of the shot—an absorbent, so to speak, 
of the shot's energy, and a bar to its progress through the plate—is indis¬ 
putable. It was shown conclusively to be so in the Tegel trials, 6 and theory 
would of course point to the same conclusion. But when we have admitted 
this, is the admission favourable or unfavourable to the Krupp system of 
ordnance, with which a lead coating of some sort is indispensable ? Is it 
not an admission of the necessity on Krupp's part to produce a large margin 
of ballistic powder in order to accomplish the same penetrative results as a 
gun which is not saddled with this dead weight of projectile ? Is it not an 
admission of an inherent defect in the system, to say that it entails the use 
of a projectile of which from one-fifth to one-fifteenth (according to the 
thickness of the lead jacket) is declared by its supporters to be useless for 
penetrative purposes ? Have we not here, indeed, some explanation of the 
fact which will appear more clearly as we proceed, that with a large 
theoretical excess of penetrative power, Krupp's gun produced penetrative 
effects not greater, if so great, as those produced by the English gun? 
Then, again, there is the question of accuracy, and Captain von Doppelmair 
is driven to admit that the inferior accuracy of projectiles with a thin 
coating may have been due to the reduced quantity of lead. 0 Finally, have 
we any assurance that the thin lead coating, upon which Captain von 
Doppelmair shows conclusively so much depends, can be applied to the 
Gruson chilled projectiles at all ? On the contrary, it appears that each 
attempt to apply the new jacket to these projectiles without detriment to 
the casting was, if not actually a failure, far short of a successful result. 7 
And while the importance of this point is fully admitted, and indee d 
insisted upon with great emphasis by Captain von Doppelmair, he can gi ve 
1 Doppelmair, p. 27. 
2 It should also be observed that 53 lbs. of prismatic is admitted by Krupp to be more than 
equivalent to 43 lbs. English, which charge is stated to be equal to 46 lbs. prismatic.—Krupp, p. 5, 
and Table VI. It is also worth while noting that, although prismatic powder is used in Russia 
with the Krupp guns, the maximum charge for a 9-inch Krupp, heavier by 4cwt. than the Tegel 
gun, and firing a light shot, is only 46 lbs.—Krupp, Table VI. 
3 Doppelmair, pp. 17-19, 25. Krupp, pp. 9, 10. 
4 See Doppelmair, p. 18, where the lead coating is altogether thrown out of the calculation. 
5 Doppelmair, pp. 32, 43. 
6 “ Perhaps also the absence of the heavier lead jacket lessens the stability of the axis of rotation 
of the shell, and so influences the accuracy of fire.”—Doppelmair, p. 33, 
7 Doppelmair, pp. 29, 36, 40, 49, 
