Experiments upon Gimpowder. 83 



than a bow of steel of the same degree of stiffness ; but 

 for practice I think it is plain that gunpowder may be 

 supposed to be so light as to be rendered entirely useless, 

 and for some purposes it seems probable that it would 

 not be the worse for' being even heavier than it is now 

 made. Vents are absolutely necessary in fire-arms, and 

 in large pieces of ordnance the windage must be consid- 

 erable, in order that the bullets, which are not always so 

 round as they should be, may not stick in the bore ; 

 and those who have been present at the firing of heavy 

 artillery and large mortars with shot and shells must 

 have observed that there is a sensible space of time 

 elapses between the lighting of the prime and the explo- 

 sion ; and that during that interval, the flame is contin- 

 ually issuing out at the vent with a hissing noise, and 

 with a prodigious velocity, as appears by the height to 

 which the stream of fire mounts up in the air. It is 

 plain that this loss must be greater in proportion as the 

 shot that is discharged is heavier ; and I have often fan- 

 cied that I perceived a sensible difference in the time that 

 elapsed between the firing of the prime and the explo- 

 sion when bullets were discharged, and when the piece 

 has been fired with powder only ; the time being ap- 

 parently longer in the former case than the latter. 



Almost all the writers upon gunpowder, and particu- 

 larly those of the last century, gave different recipes for 

 powder that is designed for different uses. Thus the 

 French authors mention poudre a mousquet, poudre ordi- 

 •naire de guerre, poudre de chasse, and poudre d' artifice ; all 

 of which are composed of nitre, sulphur, and charcoal, 

 taken in different proportions. Is it not probable that 

 this variety in the composition of powder was originally 

 introduced, in consequence of observation that one kind 



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