SHRAPNEL EIRE. 
185 
following table of the best heights above plane for the 9-pr. and 16-pr. 
M.L, at different ranges will be of use-■ 
16-pr. 
9-pr. 
Burst 
short. 
Range. 
Angle of 
descent. 
Height. 
Burst 
short. 
Angle of 
descent. 
Height. 
yds. 
yds. 
o 
/ 
ft. 
yds. 
o 
/ 
ft. 
100 
1000 
2 
20 
12-0 
80 
2 
29 
10-4 
80 
1200 
3 
0 
12-6 
60 
3 
10 
9-9 
a 
1400 
3 
40 
15*3 
a 
3 
54 
12-2 
a 
1600 
4 
25 
18-5 
a 
4 
43 
14-8 
a 
1800 
5 
12 
21-9 
a 
5 
38 
17-9 
n 
2000 
6 
0 
25-0 
a 
6 
37 
21-0 
60 
2200 
6 
57 
21-6 
40 
7 
39 
16-0 
n 
2400 
7 
47 
24-5 
a 
8 
46 
18-5 
a 
2600 
8 
45 
27-7 
ii 
9 
54 
20-9 
n 
2800 
9 
45 
30-8 
n 
11 
10 
23-6 
II 
3000 
10 
46 
34-2 
,i 
12 
34 
26 5 
50 
3200 
11 
47 
31*2 
30 
13 
53 
22-2 
n 
3400 
12 
46 
33-9 
ii 
15 
22 
24-6 
a 
3600 
13 
51 
36-7 
a 
17 
6 
27*6 
H 
3800 
14 
52 
39-7 
ii 
18 
50 
30-7 
The loss due to errors in height above plane may be seen from the 
following cases. 
Suppose the targets shown in Fig. VIII. to be a front elevation of 
the section in Fig. II. The circle whose centre is at A will represent a 
section of the cone of dispersion of the shell burst 100 yds. short, and 
those portions which give direct hits, or pass over or under; the 
circle having its centre at B will represent a shell burst at the same 
distance, but 10ft. higher; that at C, one 10ft. lower. In Fig. IX. 
the same is shown in the case of a shell 50 yds. short, burst (A) in the 
proper trajectory, ( B ) 10ft. higher than it, and (C) on plane. 
Though these losses are considerable, they are by no means so great 
as to make any of the shells inefficient, and they are quite the outside of 
the amount that should be due to ordinary errors of laying. As may 
be seen from the Shoeburyness practice, small errors in this direction 
do not entail much loss, although, of course, to obtain maximum effects 
they must be carefully avoided. 
When a shell bursts too high or too low, it must not be at once 
decided that the gun is badly laid; it may be due simply to the 
faulty boring or incorrect burning of the fuze. If any doubt should 
arise as to where the fault lies, a shell with percussion fuze will 
soon set the matter at rest; it will show at once whether the estimated 
range is correct, or—what is the same thing in practice—whether the 
gun is throwing under or over the object. If either is the case, the 
laying must be corrected; if neither, the fault is evidently due to the 
fuze. If the burst is too high, the shell is bursting short and the fuze 
must be lengthened; if too low, it requires shortening. 
5. The question of the power of the bullets at decreasing velocities 
is one of vital importance to the elucidation of the subject. What is 
the lowest velocity at which they are effective ? In some French 
