EXPLOSIVES—0’HERN, 267 
measured under the zero temperature condition specified above, but 
which at the temperature of explosion would occupy more than 4,000 
cubic inches, if similarly measured under atmospheric pressure. 
Heat developed.—The quantity of heat developed can be readily 
computed from experimental data giving the heat absorbed in the for- 
mation of the explosive material and of each of the products of 
explosion other than the simple gases, these absorbing no heat. It 
is thus determined that the heat given off by exploding under con- 
stant pressure 1 pound of nitroglycerin amounts to sufficient to raise 
approximately 2,610 pounds of water through 1° F. 
Temperature of explosion.—Knowing the quantity of heat liberated 
and the quantity required to raise the products of explosion through 
1°, the temperature of explosion can be readily computed. The tem- 
perature thus determined for the explosion of nitroglycerin has the 
enormous value of approximately 3,178° C., this temperature being 
approximately twice that of molten steel. The considerable volume 
of gas developed, the very high temperature to which raised, and the 
quickness of the reaction account for the extremely violent action of 
nitroglycerin and other explosives of similar character. 
DYNAMITE. 
Dynamite consists of nitroglycerin absorbed in a solid body called 
the ‘‘dope.”” One of the earliest dynamites was made by absorbing 
nitroglycerin in powdered ‘‘rotten stone.” As the rotten stone could 
neither burn nor explode, it was called ‘‘inactive dope.” There are 
now many varieties of dynamites with dopes of this character. On 
the other hand, nitroglycerin may be absorbed in gunpowder or in 
other active materials which will explode as well as the nitroglycerin 
when the dynamite is fired. There are large numbers of dynamites 
thus made with active dopes, and with varying percentages of nitro- 
glycerin. The following may be taken as an example of a standard 
dynamite with an active dope: 
Per cent. 
itenebyeetrn.. fs laos SIDE OL Fk a Se eee, da 40 
Bisisite,of sad9; (sodium filtrate)jos.232) :qed4sor 1s taoskesstidteespeed doaeiede 44 
a ee Ea 8 ai wo len ae oes tid ade ie 15 
Pxenotapion Mme.(ealciim carbonate): . <=.) ios = o00<dg.05 jasc tin space ccc aan 1 
OA adee ey pee i he seed Sagnse aeedoudcnen~ceaad -usht.! Baigalads: 100 
The extensive use of dynamite in this country is apparent from the 
fact that there were manufactured-in the United States in the year 
1909, as previously stated, approximately 195,000,000 pounds of this 
material. It was the explosive most largely used in digging the 
Panama Canal, the expenditure at times amounting to about 1,000,000 
pounds a month. 
