ON THE RANGE INDICATOR DIAL. 
57 
marked on the inner dial at once as they are called oat, those appear- 
ing on the front face being in each case 75 yards less. 
Similarly, of course, if it were wished to add to the range found by 
the Range-Finder, at the word “ Add 50 yards ” the arrow head would 
be moved 50 yards in the opposite direction. 
It might, perhaps, be necessary to explain to the man in charge of 
the dial that the figure at the top showing the thousands should always 
be changed when the hand pointed vertically upwards (i.e., to the zero 
point on the outer dial and not that on the inner one). It would be 
unlikely, however, after the first range had been signalled, that any 
mistake would be made at the guns as to the number of thousands of 
yards, even if the figure were not changed at exactly the right moment. 
The hands might be conveniently turned by a key or by a fixed 
handle in rear. 
In case it might be required at any time to clamp the hand in its 
position, this might be done by means of a small nut, a thread being 
cut for it on that part of the pin between the rear hand and the end 
of the axle. 
The present arrangement for showing deflection on the Range 
Indicator Dial has not been found in practice to be satisfactory. The 
presence of two hands on the face of the dial, one to show range and 
the other deflection, although they are of different colours, is objec¬ 
tionable as allowing of the possibility of their being mistaken for each 
other. Moreover, the two hands being clamped by the same nut in 
front, whenever this is loosened for the purpose of moving the hand 
pointing to the range, that showing deflection either falls down or has 
to be held in its place. It is very difficult, in fact, for one man to 
manage the two hands at the same time, and in order to do so he must 
frequently have his hands, if not his whole person, in front of the dial 
and so obscure it from the guns. 
It would be better that the arrangement for showing the deflection 
should be quite separate from that showing the range. It is proposed 
that there should be an arm, pivoted near its top end, in rear of each 
top corner of the frame. (Fide fig.) A cord fastened to the top of 
the arm, and with a loop at its lower end, should be of such a length 
that when a loop was put over the highest of the three pegs shown on 
the frame, the arm would be pulled into the position shown as repre¬ 
senting half a degree deflection. When the loop was placed on the 
second peg the arm would be horizontal, which would represent one 
degree, and when on the lowest peg the arm would be brought into 
the position represented as showing one and a half degree. The arms 
on the right and left would show right and left deflection respectively, 
and it should be made clear that the proper right and left of the dial 
was referred to, i.e., when looking from the dial towards the guns. 
When the dial was, as would often be the case, on rising ground in 
rear of the guns, its right and left would be identical with that of the 
guns, and the arms would then point in the direction to which deflec¬ 
tion was to be given. 
Note. —The writer wishes to say that when this paper Was sent in, in March, he had no know- 
ledge of Captain Elmslie’s “corrector” for assisting group officers in giving allowances for 
“ displacement,” in which the same method has been adopted for adding and subtracting the 
allowance. 
