Excerpt from The Selection of Explosives Used in Engineering and Mining Operations Practically every class and every grade of commercial explosive are used in open-air work to meet varying conditions. In breaking down rock in quarries the explosives generally employed are: Black blasting powder, granulated nitroglycerin powder containing 5 to 15 per cent of nitroglycerin, straight nitroglycerin dynamites con taining 15 to 60 per cent of nitroglycerin, low-freezing dynamites commercially rated according to the equivalent percentage of strength of the straight nitroglycerin dynamites, and ammonia dynamites rated in a similar way. In recent years blasting gelatin, gelatin dynamites, ammonium-nitrate powders containing nitro substitution compounds, chlorate powders, and the se-called nitro starch powders have been used to a small extent in quarry work. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This 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.