156 
MINUTES OF PBOCEEDINGS OF 
The two principal features of the Diaphragm shell are,—- 
(1) The complete separation of the bullets from the bursting charge by 
means of a thin cup-shaped iron partition, or “ Diaphragmand 
(2) The peculiar arrangement of the metal of the shell adopted to ensure 
the shell being opened without the flight of the bullets being affected by the 
bursting charge. 
Upon the first of these features it is unnecessary for my present purpose 
to dwell, though I may remind the reader that the Diaphragm is supported 
by four small projections or flanges on its circumference, equidistant from 
one another, which are cast into the metal of the shell, and is presented with 
its convex side towards the fuze hole, thus dividing the shell into two unequal 
parts,—the powder and bullet chambers. 
But the second feature is more directly connected with the objections 
which have been urged against the shell, and the validity of which I propose 
to consider in another paper, and must therefore be noticed a little more in 
detail. The importance of adopting an arrangement to ensure the bursting 
charge opening the shell without affecting the flight of the bullets, will be 
appreciated when we consider that otherwise not only would General 
Shrapnel's “ fundamental principle ” be violated, but the efficiency of the shell 
would be injuriously affected in the highest degree, by the bullets being liable 
to be blown up or down, or forward or backwards, according as the fuze 
happened to be below or above or behind or before at the moment of 
explosion, 1 and the effect of the shell would thus depend in a great 
degree (1) upon the accidental relative position of the powder and bullet 
chambers at the moment of explosion, and (2) (as any great dispersion of 
the bullets by the bursting charge, would produce great divergence from 
the trajectory of the shell) upon its bursting at some exact known distance 
from the object fired at,—conditions which, from the difficulty of exactly 
judging the distance of an object, and the still greater difficulty of exactly 
judging the distance of the shell from that object at the moment of fracture, 
it would be impossible to impose. For these reasons, therefore, an arrange¬ 
ment of the nature that I have indicated is absolutely essential to the success 
of the system. 
The plan adopted by Colonel Boxer is as follows: The shell is weakened 
in the interior by four grooves equidistant from one another, which taper 
proposed I had no opportunity of making the necessary experiments, to determine various details 
in regard to the arrangement of the wrought-iron partition, the depth of the grooves, &c., &c., 
which although in appearance but trifling, are nevertheless points upon which the success of the 
system depends. However, as the results of the first trials at Shoeburyness in 1852 and 1853 were 
reported as highly satisfactory, and there was neither time nor opportunity to prosecute the 
enquiries in relation to the most efficient arrangement at a period when the shells were required for 
immediate service—the original designs were adhered to. The shells in question were supplied by 
contractors, the majority of whom were totally inexperienced; and owing to the peculiarity of 
construction, it was impossible when the shells were delivered, to test or examine them in a way, to 
determine whether or not the design had been correctly carried out.owing to the above 
causes, the Diaphragm shells which has been issued for service are defective,— both in design and 
workmanship.—Remarks on Diaphragm Shrapnel Shell. Appendix. 
1 Memo, on Diaphragm Shrapnel Shell, p. 4. 
