246 Mr. F. J. Bramwell [June 13 



Then it is said the materials might have been bad, or the work- 

 manship might have been faulty. The answer to this is that we have 

 tried sami3les cut out of the very gun itself, and notwithstanding these 

 samples have been taken from pieces of metal which have been so 

 much strained all over as to have been torn asunder in many places, 

 the intervening metal from which we cut our samples, which must 

 have been equally strained, afforded good results. Moreover, the 

 splinters of the tube must have been extremely tough, for they exhibit 

 an extension equal to about 1^ inch in the whole circumference of 

 the tube. With respect to the workmanship, it was excellent, as any- 

 one may see by examining the remains. 



Next it is said that the projectile was wedged by a stud, or by the 

 wad — a papier-mache wad, as I have told you. The navy, and 

 indeed the land service, have for years used hard wedge wads rammed 

 in between the shot and the tube, and nobody ever suggested that 

 evil resulted from this practice. With respect to the stud, if that be 

 the cause, why are not guns repeatedly burst ? and how is a stud to 

 become detached from one of these shells ? I must confess I cannot 

 conceive the possibility of it. Moreover, and this is the true answer 

 to all the foregoing suggestions, and to the final suggestion, which I 

 will deal with presently, none of these supposed causes could have 

 produced an explosion in front of the projectile, and nothing but an 

 explosion in front of the projectile can account for the appearances 

 presented by the remains of the gun. 



The last and most taking suggestion is, as I have just said, open 

 to the same fatal remark ; but were it not for this, it is one of con- 

 siderable interest, as it attributes the bursting to an air space between 

 the cartridge and the projectile, or as some have suggested, between 

 the projectile and the wad which it is alleged was canted. 



You probably are all acquainted with the principle of the Mon- 

 golfier water ram, where the sudden arresting of a column of water in 

 motion causes an intensity of pressure which drives a portion of the 

 water up to a much greater height than that which had produced 

 the movement of the column. Similarly, to state it very familiarly, a 

 gunpowder ram may be produced. Assume a projectile placed some 

 distance away from the cartridge, and then that cartridge to be 

 fired. The powder, as we know, weighs probably from |^ to -J^ 

 of the weight of the projectile itself. And that the powder, or the gases 

 arising from it, being in motion and suddenly arrested by the projectile, 

 might produce a pressure immediately at the base of the projectile 

 greater than that which would have prevailed if the projectile had 

 been close to the cartridge when it was fired. With a very explosive 

 powder, a fine-grained powder and suitably fired, this may be the case ; 

 but even Avhen it is the pressure is entirely local, being confined to a 

 narrow ring of the bore of the gun in the neighbourhood of the base 

 of the projectile, and when confined to a narrow ring, enormous pres- 

 sures can be sustained without injury, and can be so sustained for this 

 very simple reason, that the narrow ring has not only its own strength 



