55 
ON THE RANGE INDICATOR DIAL. 
BY 
LIEUT.-COLONEL R. F. WILLIAMS, R.A. 
The range of a moving target is signalled to the guns by means of a 
Range Indicator Dial in the following way. As the range is called out 
from time to time, the officer in charge makes the necessary correc¬ 
tions for speed and direction of target, &c. (in fact, all corrections 
except that for “ displacement ”), and passes on the corrected range 
to the Range Dial by which it is signalled to the guns. This officer 
is, as a rule, the C.O., and his attention is so entirely taken up in 
correcting the successive ranges as they are called out at every 50 or 
25 yards, that he has no time to attend to anything else. 
There would probably be no alteration for some considerable time in 
the amount of correction required, if the course of the target were 
fairly straight and its speed remained the same. The object then of 
the contrivance which it is proposed below to apply to the Range 
Indicator Dial is to relieve the C.O., after he has made the necessary 
correction in the first instance, from paying any further attention to 
the matter until, owing to some change in the conditions, a fresh cor¬ 
rection should be required. It w r ould further allow of the range being 
communicated directly from the Range-Finder to the Range Indicator 
Dial instead of through the medium of an officer as at present, a 
perceptible saving of time being thereby effected. 
The proposed dial would stand upright and have a front and rear 
face, with 10 divisions on each to mark the hundreds of yards ; there 
2, VOL. XIX* 
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