ARTILLERY IN COAST DEFENCE. 
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district establishment; the instrument communicates electrically the 
range and training to dials fixed near the guns, and are there read off 
by the dial number. The depression range-finder requires a detach¬ 
ment of three, the observer follows up the object, keeping the cross¬ 
wires on the water-line at the bow, or if that is not visible at the 
stern (gun-layers are instructed to lay on the same points), the drum- 
reader reads out the ranges as they alter at such intervals as the 
Fort Commander directs, usually every 50, 100, or 200 yards; and 
the dial number adds or subtracts, from the range read out, the 
correction ordered by the Fort Commander and shows the corrected 
range on the dial. This range is copied on the group dials as often 
as it changes, and the dial numbers should be trained to do this as 
quickly as possible; if any delay occurs, and especially if the delays 
are irregular, inaccuracy of shooting must result. 
If the Fort Commander orders a correction which is an uneven 
multiple of 25 and the ranges are read from the drum at the 50 and 
100 yards graduations, the dial will show ranges ending in 25 or 75, 
this will make it likely that they will be wrongly read by the group 
dials, and the Group Officers correction for displacement will not be so 
easily made, it would then be better that the ranges should be read 
out at the intermediate graduations ; thus if the ranges read out are 
1800, 1850, &c., and the Fort Commander's correction is + 75, the 
ranges shown would be 1875, 1925, &c., but if the ranges are read 
out at 1825, 1875, &c., the dial would show 1900, 1950, &c. Of 
course, the Fort Commander's dial must not be so placed that the 
range could be read from the sea. 
In some cases electric dials similar to those used with position- 
finder are supplied, this is a great improvement, the dial number has 
then only to watch his dial and read out the range as it alters. 
The possibility of obtaining accurate shooting depends on the 
accuracy of observation of the results of fire, and correcting subsequent 
rounds accordingly. 
At peace practice, by the aid of look-out parties, plane tables, &c., 
this can be very accurately done, but under service conditions, such as 
a rapidly moving target covered at intervals by its own smoke and 
with, perhaps, several forts firing at it, such assistance could not be 
relied on. It would be better to train officers to judge the results of 
their fire without such extraneous aids, and it is much to be regretted 
that, owing to the small quantity of ammunition available, so few 
have a chance of such training. 
With the position-finder, when the splash of the shot can be seen, 
the error in range and direction can be quickly ascertained by the 
instrument. 
With depression range-finder also the error in elevation can be 
obtained by taking the range to the splash; it is very desirable that a 
second instrument should be provided at the Fort Commander's station 
for this purpose. 
The possible modes of attack of the fortress, having regard to the 
probable strength and composition of any fleet that might be brought 
against it, would be considered, and the best mode of resisting each 
