Excerpt from Compressed Air Practice in Mining Compressed air has proved itself in very many ways an exceedingly useful agent in coal and metalliferous mining; for transmitting energy into the working-face for drilling and cutting, and for tunnelling Operations, haulage, pumping, and other purposes. The introduction of electricity for mining threatened for a time to supersede compressed air, but experience has proved that electricity 18, under certain condi tions, a source of grave danger, so much so that stringent legislative restrictions have been found necessary. Compressed air, in regard to safety, convenience, and general suitability, has many advantages over electricity and other modes of transmitting power, and should in no wise suffer in comparisons of efficiency if more attention is given to the proper application of the system. Mining engineers in Britain and her colonies do not appear to have given the attention to this subject which it deserves, and possibly the absence of a textbook dealing with it may partly account for this. An endeavour is here made to supply this need, in the first place for students in mining schools and colleges, but it is also hoped the book may prove serviceable to those in practice. It is based upon lectures given to students, and whilst in the first chapter a knowledge of elemen tary mathematics is assumed, and in the second the calculus is used as far as thought necessary, the remainder is for the most part descriptive. A thorough understanding of the principles underlying the generation and use of compressed air in mining practice is most important, and to help students to test their knowledge numerous examples of fully worked out calculations are included In the book. 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.