of preparing and employing Gun-cotton. 549 



In the discharge of the same specimen of powder greater dif- 

 ferences than the above are met with. For instance, the gun- 

 cotton brought by General von Lenk from Austria was fired 

 twice. It gave — m . 



The 17th February 374-40 



The 8th March 408*40 



From these results we think we may conclude that both the 

 Lenk and the Bouchet gun-cottons have the same ballistic force. 



For these experiments the charge of gun-cotton occupied a 

 length of 5 centimetres in the barrel. It was proposed to try 

 it again by ramming it more strongly, and thus reducing the 

 length to 3 centimetres ; but on the first round with this form 

 of charge, and with 3 grammes of gun-cotton made at Paris 

 by General von Lenk's method, the cannon burst. 



This fact is analogous to that which has several times been 

 observed in firing the Bouchet gun-cotton. We find in it a 

 proof of the resemblance of the Austrian and the French gun- 

 cottons, as regards their bursting effects. 



We shall not revert to all the attempts of the Commission of 

 1846 to remedy this inconvenience of the too rapid combustion 

 of gun-cotton, but we may speak of those made with the same 

 view by General von Lenk. 



He at first used pressed cartridges, which did not succeed ; in 

 one of the Notes which he has communicated to us, we read that 

 a bronze gun charged with such a cartridge was rendered useless 

 by the second round. 



The cartridges which appear most to diminish the bursting 

 effect of gun-cutton on the sides of the arms are those made of 

 paper cylinders covered with woven gun-cotton, and which he 

 calls elongated cartridges [cartouches allongees). 



According to the same Note, by means of these latter car- 

 tridges, a thousand rounds of about 481 grammes each were 

 fired from a twelve-pounder [piece a douze), giving a velocity of 

 427 metres, and without injuring the barrel. 



But this velocity, at which the experiments in question stopped, 

 is less than the velocity of 480 metres obtained in France with 

 the same description of gun and a charge of 2 kilogrammes 

 of ordinary powder. This latter velocity the Commission of 

 1846 desired when it used 667 grammes of gun-cotton; but it 

 has not been shown that the cartridges of the Lenk system 

 would not be injurious to fire-arms if the quantity of gun-cotton 

 were increased so as to obtain the same velocity as in France. 



Further, the author of one of the Austrian Reports admits that 

 the desired result has not yet been attained, and that the mecha- 

 nical means employed to prevent the gun-cotton from exercising 

 its destructive effects neutralize part of its propulsive force. He 



