THE SMALL-ARMS OP EUROPE. 
9 
point), and CC' a covering mass, before the mark, of a known height 
and at a known distance CD. 
The figure shows that CC' and CD are the co-ordinates, with 
reference to the mark, of a point C' of a certain trajectory, which is 
consequently easy to find in the tables. If this trajectory happen to 
be that which gives the desired range AD , all one has to do is to take 
the sight for this distance, which corresponds to the angle of elevation 
<j> o; the point to aim at C being chosen on the line AD. 
Equally, the sight for the distance AC answering to the angle of 
elevation <f>i may he taken, and the point C' — i.e ., the top of the 
obstacle—aimed at. 
For example, we will suppose the mark to be at a distance 
AD = 1000 paces, and to be hidden by a mask 3-| metres high, placed 
about 100 paces on our side of it. These data are sufficiently near 
those found in the table for the range of 1000 paces; one should 
therefore take, either the sight for 1000 paces and aim at the base, or 
that for 900 paces and aim at the top of the covering mass. 
When, on the contrary, the co-ordinates CC' and CD are not con¬ 
tained in the trajectory which gives the range, the only case that need 
be considered is that in which the distance of the covering mass from 
the mark is too short to allow the shots to strike the latter; all the 
shots that pass over the mask pass equally over the mark. In such 
case the trajectory containing these points is that of a longer range, 
and in order to strike the mark we must go back for a suitable 
distance, which can easily be found from the table. 
For example, if the mark remain at 1000 paces, and the mask, 
100 yds. short of it, be 5 metres high, the former cannot be hit; but 
the table shows that, at 1200 paces, the ordinate at 100 paces short 
is about 5 metres high. In order, therefore, to produce an effect, the 
shooting party must be retired 200 paces, and must shoot with the 
sight for 1200 paces at the foot, or with that for 1100 paces at the top 
of the mask. 
The drop of musketry is such that, when exposed to an intelligent 
use of indirect fire, no troops could long retain a close formation ; and 
even in open formation cover will no longer furnish them with efficient 
protection, unless it is very close and of sufficient height. 
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