THE EOYAL AETILLEEY INSTITUTION. 
385 
of the different bores, and of the ammunition, and more especially by atmo¬ 
spheric influence; thus, in many cases, the elevation and length of fuze do 
not correspond: hence, the first round should always be considered as a 
trial shot, and it should be carefully observed; by this means the necessary 
corrections in elevation, deflection, and in length of fuze can be ascertained. 
The figures on the tangent scale and on the time scale of the fuze should 
not be looked upon as invariable rules for laying the gun and timing the 
fuze, but merely as starting points for the first round from a gun in a 
certain position. 
In firing common shells the spot where the projectile first strikes the 
ground, and in firing shrapnel shells the bursting interval and height of burst 
should be watched. With the former projectile, the observation will be 
much facilitated by adopting the old artillery rule, of giving less elevation 
for the first round than appears necessary for the estimated distance, so 
that the first graze should be in front of the object. The position of the 
first graze as regards range is best judged from one side of the piece; and 
as regards deflection, from a point immediately behind the gun in the line 
of fire: the former position should be taken up by the commander of the 
detachment of guns; the latter by one of the numbers serving the piece. 
The explosion of the common shell on first graze clearly indicates the 
spot where the shell strikes. Under favourable conditions of atmosphere 
and with a somewhat practised eye, a shell fired at a high-angle can be seen 
during almost the whole of its flight. 
The height and interval of burst of shrapnel shells are best judged of 
from the side of the piece; for this purpose the elevation for the first round 
should be somewhat greater and the timing of the fuze somewhat less than 
is applicable to the estimated distance. 
Correction of the laying of the gun , and of the timing of the fuze . 
32. Agreeably to the above directions on opening fire, the first two or 
three rounds should be fired with the elevation and timing decided on; a 
pause should be allowed between each round, so that the first graze and 
burst of the projectile may be observed leisurely. The elevation and 
deflection in firing common shells is then corrected according to the position 
of the first graze. If the projectile goes obviously too short or too far, 
the correction may be applied at once; if however the range is not con¬ 
siderably greater or less than the distance of the object, it is advisable to 
make no correction until after the second round. If the projectile at the 
first round strikes short of the object, and at the second at or beyond it, 
no correction is necessary, because such errors are not to be corrected by 
alterations in laying the gun. 
If the shrapnel shell bursts after grazing either far before or beyond the 
object, the distance of the object has been considerably under or over 
estimated; the elevation and timing are in the first case to be increased 
according to the observation, and in the second decreased. 
When the suitable elevation has been ascertained so closely, that it might 
be presumed that the shrapnel shell, if it did not burst, must strike in the 
immediate neighbourhood of the object, the height and interval of burst, 
if found too little or too great, can be corrected by the timing. In this 
