THE VALUE OF A HIGH SITE FOR COAST ARTILLERY. 
217 
TABLE IV. 12-5" R M. L. Gun. Mark II. 
Value of the 50 p.c. Length Zone. 
Height of Site in Feet. 
Range 
in yds. 
0 
25 
50 
75 
100 
125 
150 
175 
200 
225 
250 
275 
300 
1000 
22 
17-5 
12-5 
10-2 
8*7 
7*5 
6-6 
5-9 
5-4 
4-8 
4-5 
4-2 
3-9 
1500 
22 
19 
16-8 
15 
13-5 
12-4 
11-4 
10-6 
9-8 
9-2 
8-6 
8 
7*7 
2000 
22 
20-3 
18-9 
17-7 
16-7 
15-6 
14-8 
14 
13-4 
12-8 
12-2 
11-7 
11*2 
2500 
22 
21 
20 
19-1 
18-3 
17-7 
17 
16-6 
15*8 
15-3 
14-8 
14-3 
13-9 
3000 
23 
22-2 
21*6 
21 
20-3 
19-8 
19-3 
18*7 
18-3 
17*8 
17-4 
17 
16-7 
3500 
23 
22-4 
21-9 
21*6 
21 
20-6 
20-2 
19-8 
19-4 
19-1 
18*7 
18-3 
18-1 
4000 
24 
23*6 
23-2 
22-8 
22-5 
22-1 
21-8 
21-4 
21-2 
20-8 
20-6 
20*3 
20 
4500 
25 
24-8 
24-4 
24*1 
23*7 
23-6 
23-3 
23 
22’8 
22-5 
22*3 
22 
21-8 
5000 
26 
25-6 
25-4 
25*2 
24-9 
24-7 
24-5 
24-2 
24 
23-8 
23-6 
23-5 
23-2 
II. The Virtual Target. 
M 
Let A BCD be an objective, whose dimensions in the plane of the 
trajectory are AD = BG = a, and AB = DC = b, and let 8 be the angle of 
arrival; then any shots between MR' and ND will hit A BCD. 
Through D , draw DV at right angles to JVD or MH', meeting the 
latter in V. Then DV is the virtual target presented by the objective, 
when 8 is the angle of arrival. 
