1880.] Sequel to the * TJiiinderer' Gun Explosion. 315 



wedging, with the exception of one or two still faithful adherents, is 

 now discarded as a most unlikely cause : " Absurd to suppose that a 

 wrought-iron or steel gun could be burst with a piece of brown paper ! " 

 And with respect to the double-loading, I doubt not before many 

 weeks are over it will be found that there is nobody who did not know 

 from the very fii'st that if a gun were double-loaded and fired it must 

 burst. It appears to me that if it were only to bring persons into 

 this condition of mind, the gun has been well expended, because if the 

 truth be generally accepted and believed in, it matters little whether 

 persons remember that this desirable state of mind has been arrived at 

 against their previous convictions, or whether they delude themselves 

 into the condition of believing that they never had any other opinion 

 upon the subject, than that double-loading would burst the gun, and 

 that nothing else would. Whatever may be the origin of the state of 

 their minds, it is for the good of the service that the universal settled 

 conviction should be, that the gun was strong enough for ordinary 

 use, and was only burst by an extraordinary use, which in all pro- 

 bability never will recur, and which can be made a matter practically 

 impossible to recur. 



Other of the former suggested causes of the explosion, such as the 

 insufficiency of the gun to withstand the effects of exploding a single 

 cartridge, fired in the ordinary manner, arising either from badness of 

 materials, or of workmanship, or from the gun having been injured 

 by previous use, have practically been abandoned, and need not 

 occupy your time for one moment. Neither need we devote much 

 consideration to a novel suggested cause, which does great honour to 

 the ingenuity of its author. He says, " When pushing in a drawer of 

 a chest of drawers, if you push it on one side it sticks." I am afraid 

 the gentleman's furniture must have been defective. " Now apply 

 that reasoning to the projectile in the gun ; if you push that upon 

 one side that would also stick, and therefore the gun would burst." 

 Therefore he reflects, " If I can but find some sufficient cause why 

 the projectile may have been pushed more on one side than on the 

 other, my homely chest of drawers has enabled me to solve this great 

 problem." He no doubt had read those exhortations " to keep your 

 powder dry," and it occurred to him that if dry powder were a good 

 explosive, damp powder must be a less good explosive ; thereupon he 

 suggests that if one side of the cartridge, say the upper side, happened 

 to contain a stratification of damp powder, while the other side had 

 dry powder, that the one side of the shot would be impelled with a 

 pressure gi'eater than that which was acting on the other, the shot 

 would jam, and the gun would burst. 



I will now call your attention to the tables. Diagrams (4) and (5), 

 which show the results of firing the gun with air sjiaces between the 

 cartridge and the base of the projectile. As you will see, as many as 

 seven experiments were made with each of the quantities of powder, 

 which on all occasions was P, or pebble. The first experiment was 

 made without any air space : in the subsequent experiments the pro- 



