THE 110YAL ARTILLERY INSTITUTION. 
195 
REPORT 
of 
EXPERIMENTS WITH NAYEZ’S ELECTRO - BALLISTIC APPARATUS,* 
TO 
(1) THE EFFECT OF ELONGATING- THE CARTRIDGE ON THE YELQqiTY 
OF THE PROJECTILE, 
(2) THE EFFECT OF THE POSITION OF THE YENT ON THE VELOCITY 
OF THE PROJECTILE, 
HI CAPTAIN W, H. NOBLE, M.A„ R.A f 
associate member, orinsrAxci? sislbot commitibe. 
Experiments to determine the effect of elongating the cartridge on the 
velocity of the projectile, 
1. This subject has for a long time attracted the attention of artillery 
officers, and several important experiments have been made for the purpose 
of determining the effect of the diameter of the cartridge on the initial 
velocity of the projectile. 
The importance of the question will appear on due consideration of the 
effects of elongating the cartridge, both with regard to the preservation of 
the gun and the complete ignition of the charge. 
It is evident that if the cartridge was made of the same size as the bore 
of the gun in which it is fired, the only method by which the gas first 
developed could penetrate the rest of the charge, is by passing between the 
interstices of the grains. When, however, the cartridge is to a certain extent 
elongated, and consequently of less diameter than the bore, the gas can 
pass along the space left between the cartridge and the top of the bore, and 
thus facilitate the complete ignition. 
This gas also has the effect of causing the shot to move, and so enlarging 
the space which the powder occupies at the moment of its maximum 
tension; it thus relieves the gun by causing the initial strain to be spread 
over a greater surface. The object of the present experiment was to 
ascertain how far the cartridge could be elongated without seriously 
reducing the velocity of the projectile. 
It is impossible, within the limits of this paper, to dwell on the various 
scientific points connected with this subject. Colonel Boxer has devoted an 
Extracted from Second Report on Ballistic Experiments. 
[VOL. V.] 
26 
