182 ELEMENTARY PRINCIPLES OP GUNNERY. 



third. Now, this excess has in many experiments been im- 

 perceptible, and the velocities have been reciprocally on the 

 subcluplicate ratios of the number of bullets to sufficient 

 exactness; and where this error has been the greater, it has 

 never arisen to an eighth part of the whole; but if the 

 common opinion was true, that a small part only of the 

 powder fires at first, and other parts of it successively, as the 

 bullet passes through the barrel, and that a considerable part 

 of it is often blown out of the piece without firing at all ; 

 then the velocity which three bullets received from the 

 explosion ought to have been much greater than we have 

 ever found it to be, since the time of the passage of three 

 bullets through the barrel being nearly double the time in 

 which one passes, it should happen, according to this vulgar 

 supposition, that in a double time a much greater quantity 

 of the powder should be fired, and consequently a greater 

 force should have been produced, than what acted on the 

 single bullet only, contrary to all our experiments. But 

 further, the truth of the second postulate will be more fully 

 evinced when it shall appear, as it will hereafter, that the 

 rules founded on this supposition ascertain the velocities of 

 bullets impelled by powder to the same exactness when they 

 are acted on through a barrel of four inches in length only, 

 as when they are discharged from one of four feet." Robins's 

 New Principles of Gunnery, pp. 80-82. 



Now all the facts here adduced may, and I believe are, 

 correctly stated, and yet they do not prove the proposition 

 with which this ingenious author sets out. Moreover, the 

 difference which he explains by supposing that the flame 

 escapes by the side of the first bullet, may far more readily 

 be understood to be in consequence of the increased time 

 which the powder is allowed for explosion. The counter 

 argument may more readily be supported by extending the 

 charge of powder, by loading a small tube several inches in 

 length with it, when the grains in front are evidently blown 

 out in an entire state, proving that there is a point beyond 

 which instantaneous explosion does not go. All that Robins 

 shows by this experiment is, that the charge of powder 

 which he used burns entirely before the one ball leaves the 

 muzzle; and, if that is the case, it can do no more if one or 



