Theory of Explosives and Fumes. Definition of Explosive: Explosive is a substance either solid, liquid, or jelly, which, when subjected to a shock, suddenly changes from solids, etc., to gases, at a very high temperature, tearing to pieces any vessel which may contain them.
Definition of an Explosion: An explosion is a chemical reaction which is completed in an exceedingly short period of time with the evolution of a large quantity of gas at a very high temperature. If this reaction occurs in a body which is closely confined, the expansive effect of the highly heated gases produces disruptive effects. If the suddenness of the reaction is very great, disrupted action upon solid objects in contact with the body may be obtained even when it is unconfined, because the cohesion of these objects can be overcome more readily in an instant of time than the inertia of the surrounding air. This has given rise to the popular error that nitro-glycerine and other high explosives act downwards; as a matter of fact they act with equal force in all directions. It is evident, therefore, that the violence of an explosion depends upon three things, namely, the time occupied completing the reaction of the explosive body; the temperature produced by the reaction, upon which directly depends the expansive forces of the resultant gases; and the quantity of gas evolved by the reaction. A fourth consideration—whether the products of the reaction are the result of one set of chemical actions occurring simultaneously; or whether the set of new compounds react upon each other, producing a second set of compounds.
LECTURE III.
STUDY OF A FEW OF THE PRINCIPAL
TYPES OF RIFLE AND HAND
GRENADES.
General. The undermentioned types of grenades, empty, are issued for instruction:—
(a) Grenade, 303-inch, short rifle, No. 3, Mark 1. (J. pattern.)
(b) Grenade, hand, No. 1, Mark 1.
(c) Grenade, hand, No. 5, Mark 1.
(d) Grenades, hand, Nos. 6 and 7, Mark 1.
These grenades were also known as (a) Hales Rifle Grenade; (b) R. L. impact or percussion grenade; (c) Mill’s pattern grenade; (d) R. L. grenades, friction, time.
Of these (a) is for firing from the point .303-inch short rifle. Its range is about 200 yards.