ARTILLERY FIRE. 
59 
during the interval of firing (where k may be negative) the diminishing 
corrections of range for the 1 st 2 nd , 3 rd ,. n th shots should be 
k+p i 
fe + h Pi 
h + iPs 
Tc + -p„_i yards 
when r p n _ 1 is the over error of the (n ~ l) th shot. In some cases it is 
considered preferable to secure over rather than under errors. The 
effect of this is merely to advance the desired centre of impact beyond 
the target a small distance e, thus making the corrections successively 
i (p<i - e) 
h {Ps ~ e) 
n 1 
(Pn-l ‘ 
Guns in the service cannot in general be corrected for smaller dis¬ 
tances than 25 yards of range, so that the above perfect system is 
impossible of perfect execution. However, a knowledge of the prin¬ 
ciples applicable to a weapon with which it is possible to carry out the 
theoretically perfect corrections cannot fail to be of advantage in the 
study of an imperfect weapon. 
For example, p n _ } being the actual error of the (n — 1 th ) shot, the 
correction for the n iXl shot is theoretically — 
1 
n — 1 
Pn-V 
TABLE FOR CORRECTION OF FIRE. 
Correction for 
0 
25 
50 
75 
100 
125 
150 
yds. 
Error of— 
1st shot 
<12* 
<12!>37! 
>37! <62! 
>62! <87! 
>87!<112! 
>112! <137! 
>137! <1621 
yds. 
2nd „ 
<25 
<25 >75 
>75 <125 
>125<175 
- 
— 
- 
- 
3rd „ 
<37* 
<37!>112! 
>112! <187! 
- • 
— 
- 
- 
4th „ 
<50 
<50 >150 
- 
- 
- 
- 
- 
- 
5th „ 
<62* 
<62! >187! 
- 
- 
- 
- 
- 
- 
6th „ 
<75 
<76 >225 
- 
- 
- 
- 
- 
- 
7th „ 
<87! 
- 
- 
- 
~ 
- 
- 
- 
