128 
AUTO-SIGHTING. 
I propose to deal with these two objections. 
1. “The actual errors of laying an automatic sight in 1897 when 
tried by a committee of experts” are given in a tabular form and 
present an alarming appearance. With a height of gun of 150 feet, 
the error recorded at 3,900 yards was 890 yards, which is evidently 
prohibitive. The auto-sight employed was, however, merely a device 
for moving the back sight. The line was taken by the unaided eye 
over sights of service type. If such sights were affixed to the excellent 
D.R.F. or P.F. instrument, I think that the errors would be found to 
be surprising; but this only proves that, except at comparatively 
short ranges, the unaided eye is prone to deceive, and even the 
difference between a “fine” and a “full” sight is considerable. 
With the D.R.F. and the P.F., therefore, a telescope was found to be 
essential. In the case of an auto-sight, the same need obviously 
arises, and for the same cause. As Colonel Watkin points out “in 
certain weathers, in fog and with powder smoke hanging about, a 
telescope cannot always be used with advantage ” ; but there will not 
be much “ powder smoke ” in the actions of the near future, and as 
regards certain weathers and fog, what is sauce for the D.R.F. or 
P.F. is clearly sauce for the auto-sight. Practical experience has 
brought out in the most striking way the fact that the telescope could 
be most effectively used in conditions which rendered ordinary sights 
absolutely useless. Except in the case of short ranges, a telescope is 
an essential feature of an auto-sight, and the failure to recognize this 
axiom is the reason that neither of the arrangements described by 
Colonel Watkin can fulfil the necessary requirements. Auto-sighting 
apart, the telescope sight which has hitherto been a monopoly of the 
mounted branches, will prove an immense gain to the Garrison gunner. 
The purely observation errors introduced will be no more and no less 
than those which arise in using the D.R.F. 
2. The question of securing the verticality of the axis about which 
the gun traverses is extremely important; but I am inclined to demur 
to the expression “ want of level of the emplacement, platform, etc.,” 
which suggests that half-a-dozen or more things have to be accurately 
adjusted. Auto-sighting, if the best results are to be obained from it, 
demands that the level of the racer path shall be true within narrow 
limits. Its application “ to the older form of guns and platforms is 
out of the question,” as Colonel Watkin quite correctly states. It 
would obviously be unsuited to a 64-pr. on a Garrison standing 
carriage; it would confer no advantage on a 9-in. R.M.L. gun stand¬ 
ing on weak and wavy racers. I well remember an expensive fort in 
which the rear racers of slight section were attached to wooden chocks 
nailed between floor joists ! In such a case and in many others I 
should certainly not recommend any attempt to employ auto-sighting. 
We are not, however, concerned with the past. It would be unprofit¬ 
able to apply a water-tube boiler to a Newcomen engine or a quick- 
firing breech mechanism to a demi-culverin. An invention can justly 
be criticised only in regard to the conditions of the times at which it 
appears. 
