130 
AUTO-SIGHTING. 
If the racer path is inclined backwards the errors would be practically 
the same in amount but +. 
If the correction is made from an observation at 3,000 yards, the 
table on the previous page becomes 
Range. 
Errors in range. 
Vertical error. 
1,000 
— 30 yards 
— 2 - 9 feet 
2,000 
- 34 „ 
- 5 „ 
3,000 
o „ 
0 „ 
4,000 
+ 38 „ 
+ 13-6 „ 
I need hardly point out that the above tables assume that firing 
proceeds on the line of training at which the correcting observation is 
made ; but my object is to show that the hypothetical defect on which 
Colonel Watkin dwells is not inherent in the principle of auto-sighting 
and that the amount of error introduced depends practically upon 
whether the gun is fired approximately on one line of training or 
whether that line varies through a wide angle. This error would, 
therefore, not prevent accurate practice either at a stationary target, 
or at a target moving in a tolerably direct line towards or away from 
the gun. The auto-sight is, in fact, not by any means so helpless as 
it has been made to appear. At the same time, the question of main¬ 
taining the vertically of the axis of the mounting is one that every 
auto-sight inventor must evidently face. 
I cordially agree that the application of auto-sighting to “ the older 
nature of guns and platforms” would be useless, and I have made no 
attempt to design a sight for these interesting memorials of a by-gone 
age. Since the days when the 9-in., 10-in., 11-in. and 12‘5-in. R.M.L. 
guns were made, we and other Powers have moved far and fast. 
These guns in their day were excellent. That day has now passed and 
we have to meet new conditions. If our coast artillery is called upon 
to fight, its opponents will be armed with the best modern weapons 
whose speed of fire and accuracy is immensely superior to that of the 
short R.M.L. ordnance. Thus the 2nd class cruiser Eclipse steaming 
at sixteen knots on a course parallel to a straight coast line and 
passing 1,200 yards from a coast battery could, at peace practice, fire 
about:— 
168 rounds 6-in. Q.P. inside 4,000 yards range 
242 ,, 4* 7-in. ,, ,, ,, ,, „ 
412 „ 12-pr. ,, „ 3,000 ,, 
There is nothing in these figures to cause alarm. It would be easy 
with a single 6-in. Q.F. gun provided with an auto-sight to put 
forty shell into the Eclipse during the fourteen minutes she would be 
within 4,000 yards, when steaming at this speed and being hulled 
three times a minute, her chances of hitting a target eighteen square 
feet in area would be remote. But a battery of (say) four 9-in. R.M.L. 
guns and two 64-prs. worked by P.F. using Case III. would 
apparently be somewhat heavily handicapped in engaging such a 
vessel in free manoeuvring waters* 
