VI. Investigation of the law of burning of modified cordite

Some years ago the eminent French chemist Vieille first propounded the law of combustion by parallel surfaces for smokeless propellants. By a propellant we distinguish an explosive which explodes from one that detonates; and it is this combustion by parallel surfaces which is the distinguishing characteristic of the difference of the two phenomena. Since Vieille first propounded his theory it has been generally accepted as correct. Investigators, however, have not, so far as I am aware, definitely determined what the law is. The general assumption has been that the law is of the form S =α Pn , where S is the skin burnt in a given time under the average pressure P,α andn being constants for the given explosive.