Coal Mining

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Excerpt from Coal Mining: Described and Illustrated To extract coal from seams lying on low inclinations has been very successfully practised in the older mining countries. In some of the provinces of France, where the coal seams incline upwards of 70°, and which are comparatively thick, much difficulty was formerly experienced in attempts made to mine out the coal entirely. Galleries driven into the coal seams horizontally, with pillars of certain widths left between them, resulted in much of the coal being lost, after it was detached from the pillars. It was then often buried by the rocks which caved in near the ends of these pillars. This occasioned a change to the present system of working by remblais, which seems to be a plan well adapted to the taking out of the coal of highly inclined coal seams. Ventilation of coal mines is treated in the following pages only in the most practical manner. To comprehend the fine points connected with mine ventilation on an extensive scale, an accurate knowledge of pneumatics with much practical experience is absolutely necessary. Absurdities connected with this important subject have floated into the works of very eminent writers, and it will not be an easy task to eradicate them. The chief difficulties in the way of practical ventilation of mines seem to consist in the maintenance of the air-passages of sufficient size free from obstructions, and in the resistance met with by air-currents moving with high velocities. Trusting that the succeeding pages will be found of use to the student of coal mining and to the operator of coal mines and the owners of coal lands, and that they may be of interest to the general reader as well, the author passes them over to the public with a consciousness of having thus done something towards performing his duty towards his fellow man. 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.