Firing a Cannon From a Cannon 



An inventor's ingenious plan to bring 

 down aircraft flying at great heights 



ONCE upon a time, so an old fairy 

 tale runs, a lunatic wanted to bom- 

 bard the moon. He invented a 

 shell that was 

 in itself a 

 cannon. 

 During its 

 flight, this 

 projectile- 

 cannon would 

 discharge an- 

 other shell, 

 which was 

 also a cannon. 

 And so by firing 

 successive cannons 

 within cannons the 

 lunatic thought that 

 he might -cover the space 

 of 260,000 miles that sep- 

 arates us from our satellite. 



Now that cannon must be 

 fired at elusive aircraft, this 

 ancient idea has been revived 

 in earnest. Airplanes must be 

 fired at point blank, there is 

 neither opportunity nor time 

 to figure out the exact 

 range. On the other hand, 

 the explosion of the shrap- 

 nel-shell is not so easily 

 timed. The hail of 

 bullets that follows 

 the bursting of 

 shrapnel meets so 

 much more air re- 

 sistance than the shell itself that not only 

 is the scattering effect too great, but the 

 striking force is too small. If by any chance 

 the explosion be timed too early, the 

 scattering effect is 

 not sufficient and the 

 airplane is not winged 

 as a shot-gun wings a 

 snipe or a quail. 



Andrew W. Gra- 

 harn meets this diffi- 

 culty by inventing a 

 shell that is not merely 

 an envelope to hold 

 bullets together for a 

 certain distance, as in 



J 



Firing pin 

 Cartridc^e timing disk \ Coi 



Rifled bai-re 



Revolving sleeve 



The ordinary fuse used in shrapnel sets off the 

 charges of the rifled passages of the shell 



shrapnel, but which, like that in the fairy- 

 tale, is a gun in itself, and a very 

 powerful Gatling gun at that. 



The projec- 

 tile is pierced 

 with a dozen 

 or so of 

 rifled chan- 

 nels, each 

 constituting 

 a barrel 

 loaded with a 

 regulation 

 rifle cartridge. 

 The inventor 

 has provided 

 a lock and 

 firing pin for 

 each hole and 

 a clock-work 

 mechanismto 

 fire simulta- 

 neously series 

 of barrels or 

 holes. This 

 mechanism 

 seems a need- 

 1 e s s and 

 hardly feasi- 

 ble complica- 

 tion. Such is 

 the concus- 

 sion in a shell 

 when it is 

 fired from a 

 gun tnat the 

 shrapnel balls must be cemented together. 

 How will clock-work endure a shock that 

 even solid balls cannot withstand? The 

 fuse used in shrapnel, 

 a marvel of accurate 

 mechanism, adapts 

 itself to setting off 

 the charges of the 

 rifled passages of Mr. 

 Graham's shell. By 

 thus discarding the 

 clock mechanism, the 

 barrels or rifled holes 

 can be made longer, 

 which means greater 

 accuracy of fire. 



The Gun Within a Gun 



A shell like that which Mr. Graham 

 has conceived can be timed to dis- 

 charge its bullets efficiently, far from 

 its target, unlike shrapnel. The bul- 

 lets do not lose in velocity, thanks 

 to their elongated form and their 

 rotation. Their velocity is the sum 

 of the shell's velocity and their own. 

 Were it not for the centrifugal action 

 of the shell, they would not scatter. 

 The firing can be timed so that at 

 least one volley will scatter properly. 



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