466 
ARTILLERY IN COAST DEFENCE. 
whether it was well short or close up. We cannot estimate the amount 
by which it was short, or at least any such estimate is likely to be very 
misleading, but we can almost always tell that it was certainly a good 
deal short or not very much short. If not short or close up, we should 
have to take off another 200 yards elevation and try again; but if 
well short, the greater part of the guns, which have been told off as 
“ salvo guns,” are loaded and laid at an elevation somewhat shorter 
than that of the first shot, in this case at 1750 yards, the fuze (for 
time shrapnel) being bored accordingly. The whole of the guns are 
kept-laid on the object, the “ ranging guns ” with an elevation of 1800 
yards, and the “ salvo guns ” with 1750 yards; and at intervals a shot 
is fired from one of the ranging guns. As long as these shots are 
observed to fall short, we know that the object has not yet arrived at 
the 1800 yards range ; but as soon as one is observed to hit, or to fall 
over, we know that it has arrived at or passed that range, and, making 
a short pause, a salvo is fired from the salvo guns ; the ranging guns 
are again loaded and laid at 1600 yards elevation, and the salvo guns 
at 1550 yards, and the process repeated. If the object had been 
retiring instead of advancing, the process would have been reversed; 
the first shot would then have been fired at a range greater than the 
estimated range, and if that fell well over, the salvo guns w r ould be 
laid with an elevation 50 yards more than that of the ranging guns. 
Now what was done in the above example was, that a range of 1750 
yards was predicted as the range at which to fire the salvo guns; and 
by using a portion of the guns (in practice usually two guns are told 
off for this purpose) as a range-finder, we were able to tell when the 
object had advanced to within 50 yards of the predicted range. The 
difference of 50 yards is to allow for time to observe the result of the 
last ranging shot, to communicate to the salvo guns the order to fire, 
and for the time of flight of the projectiles. If the speed of the object 
is increased, a larger difference must be made between the elevations of 
the ranging and salvo guns; and also a larger difference between two 
successive predicted ranges. 
Where several groups are beiug fought together under this system, 
the leeward group would usually be told off as the ranging group, the 
remaining groups as salvo groups, and the fire control would be in the 
hands of a Sub-Commander; where one group is acting alone the 
Group Officer would have to control the fire, and would tell off his two 
leeward guns as range-finding guns. 
This system would usually be employed with guns of the movable 
armament, or those of the secondary armament not supplied with the 
depression range-finders, but even guns of the primary armament must 
be fought by this method, if their position or range-finding instruments 
are for any reason unavailable. 
The ammunition to be used depends on considerations already treated 
of under “ Fire Tacticsif boats are to be attacked, time shrapnel 
will be used with the salvo guns, and percussion shrapnel or common 
from the ranging guns, according to the size of the guns ; from small 
guns common is the best to use on account of its larger bursting 
charge, but wifh medium and heavy guns shrapnel would be preferable 
