Excerpt from The Effect of Stemming on the Efficiency of ExplosivesAll commercial explosives owe their power of doing work to the expansive force of the great volume of gas evolved from them at the moment of explosion. The pressure exerted by this gas in the drill hole or other confined space in which the explosion is brought about is what makes explosive substances of value in mining or other industries and is the primary cause of all those manifestations of energy that follow the firing of a charge.Common black blasting powder, on explosion, produces about 390 times its own volume of permanent gases, 40 per cent dynamite pro duces about 530 times its own volume of permanent gases, and nitroglycerin produces somewhat more than 747 times its own vol ume of permanent gases. These proportions of volume of gases to volume of explosive are those that would be found if the gases were measured under normal conditions of temperature and pressure, but at the moment of explosion the gases are highly heated, and there fore tend to occupy a volume much greater than that represented by the figures given above.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.