78 
MINUTES OF PROCEEDINGS OF 
; the relative flatness of trajectory AD'B' varies as . Thus the 
trajectory ALB is the flatter of the two, although having the same 
absolute height. 
The relative shooting powers of different guns have been compared 
at Shoeburyness on this principle— i.e., firing them at equal elevations; 
and so long as the muzzle velocities of both the guns are the same, and 
the times of flight observed are approximately the same , the difference in 
range affords a fair criterion of their respective shooting powers. But 
there is another point which should not be forgotten, which, if lost 
sight of) may give rise to an error in judgment. If the muzzle 
velocities of the guns are not the same for equal elevations, the upward 
velocities of the shells are not the same; they are proportional to the 
muzzle velocities. For instance, suppose two guns laid at 2° of eleva¬ 
tion, their muzzle velocities being respectively 1100 and 1200 f.s.; the 
upward velocities of their shells will be in the same proportion—viz., 
as 11 to 12; and since this upward velocity really forms the time allow¬ 
ance for the shell to travel in, one has less lime to travel in than the 
other, in about the same proportion, and consequently does not range 
so far as it otherwise would. It would not be supposed that one train 
travelled faster than another if one went 12 miles in 12 minutes and 
the other 11 miles in 11 minutes. The question of time comes in; and 
it is to this point that attention should be especially drawn, as it is .so 
easily overlooked. For this reason it is not correct, in the comparison 
of two different guns, when the muzzle velocities' also differ, to judge 
exclusively by their respective ranges at the same elevation. The shell 
with the lower muzzle velocity is unfairly handicapped in point of time, 
and if its velocity is diminished less rapidly than that of the shell starting 
with the higher muzzle velocity, the gun which may be the hardest 
hitter at ordinary artillery ranges appears to be inferior to the other, 
because, at low angles of elevation, it does not range so far. This 
seems to have been the case at the comparative trial of two 16-pr. guns 
at Shoeburyness last year, one having a calibre of 3’3 ins., the other a 
calibre of 3*6 ins. The Committee recommended the trial of the 3‘3-in. 
gun for the following reasons :— 
(1) They believe that a 3*3-in. calibre is theoretically the best for a 
16-pr. gun, as giving a greater velocity at 1000 yds., and at all follow¬ 
ing ranges, over a gun of 3'6-in. calibre. 
(2) A shrapnel shell adapted to a 3*3-in. calibre takes an equal 
number of bullets, and is lighter than that for 3‘6-in. calibre. 
(3) A common shell for the 3*3-in, calibre, and of the same weight 
as that for a 3*6-in. calibre, holds Joz. more bursting charge.* 
The experiment was conducted in this way :—Each gun was fired at 
2°, 5°, and 10° elevation respectively, and the range and deflection 
observed. Table I. gives an abstract of the practice. 
Proceedings of Department of Director of Artillery,” Vol. IX. Part 2, p. 116. 
