GOLD MEDAL PRIZE ESSAY; 1879 . 
523 
same time capable of being detonated to a certainty by a moderate (say 
15-grain) detonator. This cam, we think; be produced. We must 
guard against prematures in the gun by careful manufacture and 
increased strength in the walls of our common shell. This latter step 
is also required to prevent that breaking up on impact so common at 
present; and which is a fatal defect. Prematures from defective fuzes 
do not appear to be so dangerous; as they generally take place outside 
the gun. They appear to be very rare with our present field guns; and 
we hope will be still more so in future. This question of prematures 
is one of great importance; as a burst in the bore of a gun-cotton 
shell would probably disable, even if it did not burst, the gun. 
The effect of detonated gun-cotton is certainly equal to four times 
that of the same quantity of gunpowder, and we should think that the 
bursting of charges of 2 lbs. of cotton, which could easily be put into a 
strong 24-lb. shell moving with the high velocity of the proposed gun, 
would rapidly destroy ordinary field parapets, say from 12 to 15 ft. 
thick at the top. In all probability these shells would be broken up 
too small to be effective man-killing weapons when burst on graze in 
the open. 
In order to estimate roughly the comparative effects of common shells 
when fired at earthworks or masonry, we may lay down the following 
rules, viz.:— 
(1) Effect varies directly as the energy. 
w . r 2 
2 ~"x 2240 ^ ons 3 w -^ ere W = weight of shell in lbs., and V 
The energy, of course, 
the 
striking velocity. 
(2) The effect varies in a higher ratio than the bursting charge; 
but as we cannot express exactly what this ratio is, and to be sure of 
not over-estimating our power, we shall say effect varies as bursting 
charge. 
(3) If gun-cotton be employed, the effect is from three to four times 
that of an equal weight of gunpowder. 
What, then, would be the comparative effect of the present 16-pr. 
common shells and those of the proposed 24-pr. at a range of 1300 yds. ? 
The striking energy in foot tons is 96 in case of the 16-pr., and i6- pr . and 
216 in case of 24-pr., or as 4 is to 9. The bursting charge would be con1 ' 
about J more, or as 3 is to 4. The total effect, then, supposing gun¬ 
powder used, would be as 12 is to 36, or the 24-pr. would be three 
times as powerful. Supposing gun-cotton to be three times as des¬ 
tructive as powder, we should have the new gun nine times as effective. 
Let us remember, too, that supposing the 24-pr. only to shoot as well 
as the 16-pr., the chances of hitting what we are firing at would at 
this range be more than 8 to 5 in favour of the former, on account of 
its flatter trajectory. 
These considerations certainly open up the prospect of a vast and 
welcome increase of power, even in the immediate future; which, 
however, if we obtain, will be none too soon, if future artillery is to take 
