322 Grubb — A New Collimating- Telescope Gun- Sight for large and small Ordnance. 



Let us consider first the principle of the ordinary sighting of a rifle, and see 

 where the faults exist, and how they can be remedied. In the ordinary system, 

 it is necessary for correct aiming that the eye of the observer, the object, and 

 the fore- and back-sights of the gun, be all brought accurately into line. This 

 can only be effected by viewing simultaneously the back-sight, fore-sight, and 

 object superposed on one another, and centring them, so to speak, over each other 

 with as great accuracy as is possible. 



Now the human eye has wonderful power of judgment in matters of symmetry, 

 and if it were possible to see these three objects (back-sight, fore-sight, and 

 target) distinctly and simultaneously, there is no reason why this system should 

 aot give very fairly accurate results; but everyone knows that if we direct our 

 attention to the distant object, in whicli case our eye will automatically focus 

 itself on that object, the fore-sight will be indistinct and blurred, while if we 

 focus our eye on the fore-sight, the object will appear indistinct, and the same 

 reasoning applies to the back-sight, with even greater force, as it is so much 

 closer to the eye. 



The process of aiming or sighting with ordinary gun-sights, therefore, involves 

 the centring, or matching, of three objects on each other, of which only one 

 can ever be distinctly seen at any one time, and therefore the operation is most 

 unsatisfactory and unscientific. 



It is quite true that many possessing abnormally keen sight, and much 

 perseverance, have done marvellous work with the present arrangements, but 

 these are the exceptions, and that they do make excellent shooting, by no means 

 disposes of what is said above, as to the defects of the present system.* 



It will naturally occur to the reader that the attachment of a small telescope 

 to a gun would solve the problem. In this case, the object could be viewed 

 simultaneously with a pair of cross lines or other device in the eye-piece, and the 

 arrangement would be free from the defects mentioned as inherent to the old 

 sights. There would be only two objects to match, and these could be seen 

 simultaneously and perfectly sharply. 



No doubt, with telescopic sights, any desired accuracy of aiming can be 

 obtained, but that the ordinary telescopic sight does not meet all the requirements 

 of the case is sufficiently evident from the fact that, although such sights have 

 been before the public for many years, they have not to any great extent replaced 



* It is likely, so far as military interests are concerned, and more particularly so long as our army is 

 recruited as it is at present, that the most suitahle system will not be that which will enable a few keen- 

 eyed men, with determined perseverance, to attain to a wonderful pitch of perfection, but, on the 

 contrary, the more useful system will be, that which will enable the average man, with very little 

 training, and very little practice, to shoot practically as well as the best. 



