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to prove that the practice with these shells as regards accuracy of flight 
was at least up to the average of practice with spherical projectiles of the 
same weights. 
As regards the negative evidence available for the same object, the 
following appears to me sufficiently conclusive: I can discover only two 
unfavourable opinions professing to be based upon practice or experiment 1 2 
respecting the accuracy of flight of these projectiles. 
The two unfavourable reports are as follows 
(a) A report made in 1857, which says : “ The weight of the bullets being 
all on one side of the shell causes an irregular motion, and consequently 
great inaccuracy in the flight of the projectile.” 3 And (6) a report made 
by another officer in 1858, to the same effect: “ With the same charge and 
elevation, and only a few ounces different in the weight of the shells, the 
range of one would exceed that of the other by 200 or 300 yds., while also, 
owing to their eccentricity, the lateral deviation was very great.” 3 
These, then, are the two, and, as far as I can discover, the only two, 
instances in which officers speaking from practice and experience , and not 
merely on theoretical grounds , 4 have reported unfavourable of the accuracy 
of flight of the Diaphragm shell; and the case against the projectile in this 
respect rests therefore, solely upon these two reports. 5 
This not a very strong case, and when we take into consideration the mass 
of evidence pointing to a different conclusion, hardly strong enough to make 
it necessary to do more than prove that supposing great inaccuracy of flight 
did occur with these projectiles, the effect could not possibly have proceeded 
from the cause so confidently assigned. I prefer, however, before I proceed 
to the theoretical aspect of the question, and with a view to rendering my 
vindication of the Diaphragm shell more complete, to endeavour to account 
for the only two exceptions to the generally favourable testimony borne to 
the accuracy of flight of these projectiles, by officers who have actually 
experimented with them. The following explanation suggests itself:— 
In speaking of the accuracy of these shells it is necessary carefully to 
distinguish between Accuracy of Eire, and Accuracy of Flight. By Accuracy 
of Fire is meant the accuracy, with respect to the object fired at, at which the 
shells burst; and this will depend upon a variety of conditions, chief among 
which may be named an accurate estimate of the range, correctness of line 
and elevation, accuracy of direction of the projectile, and correct adjustment 
and action of the fuze; by Accuracy of Flight is meant only accuracy of 
direction up to the bursting point; Accuracy of Flight is, in fact, only one of 
many elements necessary to secure Accuracy of Fire. Now it is evidently 
1 The opinion of the Inspector General of Ordnance, at Calcutta, was entirely theoretical, for the 
Select Committee says: “ It does not appear from the coiTespondence that any experiments were 
made at Dum Dum to prove the correctness of the opinions entertained by the Inspector-General 
of Ordnance.”— Committee’s Memo . on Diaphragm Shrapnel Shell , p. 4. 
2 Synopsis, &c., p. 295. 
3 Supplement to Deport of Ordnance Select Committee on Shrapnel Shell, p. 18. 
4 I have already pointed out ( see note 1) that the opinion expressed by the Inspector of Ordnance 
at Calcutta, was a purely theoretical one. 
3 See P.S. appended to this paper, respecting Reports made in 1863 from 30 Artillery stations, 
in none of which the shells are stated to be inaccurate in fight. 
