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by flame, and of course the expansive power of this part of 

 the charge is lost. Many other facts might be adduced to 

 prove that powder burns progressively : if a mass be fired 

 on the surface, an appreciable quantity of time elapses before 

 the lower particles are ignited, and if this occurs in the bore 

 hole of a rock, (and it always does happen on the old plan), 

 the quantity of powder effective towards rending the rock is 

 a small part of the whole charge, because but a small portion 

 is expanding at one instant. Now, if by any means we can 

 ignite the whole of the charge at once, then we have its full 

 . effect developed, and a much smaller quantity of powder will 

 be necessary to produce the same results. I may liken this 

 phenomenon to the exertions of one thousand men in pushing 

 down a wall — if each individual exerts his effort at a different 

 moment from either of his companions, we have but the effort 

 of one man to overset the wall, and it stands in perfect security; 

 but if the one thousand men combine their strength into one 

 simultaneous effort, then we have a one thousand man power 

 against the wall, and down it falls ; so is it with the charge of 

 powder in the rock, if a portion only is burning at one time, it 

 is the expansive force of this portion only that is available ; if 

 the whole be exploded at once, then we have the fullest possible 

 effect. This firing of every particle of powder at once is 

 obtained by the use of the galvanic cartridge, which pours a 

 volume of flame into the body of the charge, and consequently 

 every particle is ignited. It is to the use of these various 

 improvements that the extraordinary saving of powder by 

 this new plan is to be referred. As I before stated, one 

 gentleman says that he finds lib. of powder as efficient in 

 this way as lOlb. is on the old system. I only ask a trial 

 for your own sakes. I gain nothing by it, but the pleasure 

 of knowing that I have been instrumental in giving security 

 to the workman, and of pointing out a mode of gain to the 

 master. 



M 2 



