256 
CLASSIFICATION OF BATTERIES 
or with certain intervals between them, at a long range—say 1800 yds.—- 
and the holes carefully counted afterwards. All we have to remember 
is, that the range must be the same for all batteries, and that it must 
be a long one; for if a short range be used, the targets will be so 
riddled that it will be impossible to count the holes fairly. By 
counting the holes instead of the hits , we include penetration as well 
as accuracy . 
Common /Shell . 
From the nature of the case, practice with common shell is more 
difficult to estimate than that with shrapnel. One battery may drop 
all its common shell close round the target without hitting it, and 
count nothing; while another may send a few shell through, for which 
it counts, and drive the rest far and wide. In such a case, the practice 
of the first battery is obviously better than that of the second; how is 
the comparative value of the practice, then, to be estimated ? 
All we have to do is to lay down a standard range of, say, 1800 yds. 
for all batteries, and mark, by means of eight pegs, a circle of given 
radius—say 20 yds. round a target of the ordinary dimensions. The prac¬ 
tice with the common shell can be then carried out in the usual way, and 
with the present Battery and Range Reports, with the exception of two 
small particulars. The guns should be laid on the centre of the bottom 
of the target, not on the bulks eye; and the officer on range duty 
should note in the column of remarks the number of shell which fall 
within the circle. From this simple datum —the number of shell, out 
of a given number of rounds, which fall within the radius of a given 
circle—may be calculated in five minutes the radius of the u probable 
circle,” which I propose as the standard of merit of each battery. 
The “ probable circle,” I need hardly explain, is that circle, at a given 
range, within which it is even betting that half the shell will fall.* The 
smaller this radius, of course, the better the shooting. I must point 
out that there is no connection whatever between the “ probable 
circle” of a battery and the “probable rectangle” of a gun, except 
in so far that both are calculated according to the principles of the 
theory of Probability. The “ probable circle ” is a standard for com¬ 
paring the efficiency of shooting of the collective personnel of different 
batteries, the gun being eliminated from the question as far as pos¬ 
sible ; while the “ probable rectangle ” is a standard of comparison 
between different puns, the personnel being eliminated as far as possible. 
It may be asked, Why take the trouble of calculating the radius of 
the probable circle at all ? Why not rest satisfied with the number of 
shell which fall within the circumference of the circle pegged out 
round the target, just as in the case of shrapnel we were contented 
with the number of holes in the target ? The reason is this :—With 
shrapnel considerable expense would be incurred in providing proper 
targets, &c., and the measurements and calculations requisite to deter¬ 
mine any “ probable ” figure would involve a vast amount of trouble 
and time. There would be little or no return, too, for all this trouble, 
time, and expense ; for the result would be practically almost useless. 
* See “ La Dispersion Naturelle des Projectiles,” par A. van Muyden, Capitaine d’Artilleries 
Lausanne, 1876, p. 12, note 1. 
