PREFACE TO SECOND EDITION Any one who has been closely associated with the practical operation of coal mines will realize quickly the need of technical knowledge relating to the safe and economical production of coal. In no department of the work is this need more urgent than in the ventilation of the mine. A knowledge of the properties and behavior of the gases found or generated in the mine, and the means for effecting their safe removal or rendering them harmless are of chief importance, requiring careful study combined with practical experience in the operation of mines. Experience, without a knowledge of the theory of mining, is little better than is the possession of such knowledge by one who has had no experience in the practical work. Experience and knowledge must go hand in hand. The problems relating air, gases, ventilation, safety lamps, breathing apparatus, rescue work, gas and dust explosions in mines are treated in a thoroughly practical manner, while at the same time showing their correct solution. Formulas must always play an important part in mine ventilation and their treatment is made as simple as possible. No effort has been spared to make this volume a standard of ventilating practice. With this end in view, the various constants used have been carefully selected and are those most generally adopted. Particularly is this true of the tables of weight and measures and the conversion tables relating to the common and metric systems given in the Addenda. Their use is recommended. The present volume, which replaces the little booklet issued by Coal Age, some time previous, under the same title, will be recognized as a second edition of that handbook, though greatly enlarged by the addition of whole new sections on Safety Lamps, Oils, Breathing Apparatus, Rescue Work and numerous tables, making it a complete treatise on the subject. The author desires to thank those who have generously lent their M1.26825 aid in the work, among whom he would particularly mention James W. Paul, Mining Engineer, Federal Bureau of Mines, and J. T. Ryan, Vice-president and General Manager, Mine Safety Appliances Co., Pittsburgh, Pa. NEW YORK CITY, June, 1920. JAMES T. BEARD. PREFACE TO FIRST EDITION In March, 1913, there was started in Coal Age a department entitled "Study Course in Coal Mining," and each week following that date there have appeared two pages of matter in pocket-book form, which were intended to be later compiled and published as "The Coal Age Pocket Book." The publication of these weekly pages was not confined to a consecutive order, which gave to that department of Coal Age an increasing and widening interest among readers and students of technical mining subjects. The matter treated was in response to the requests of coal-mining men, who were seeking to know the development of formulas, the explanation of principles, and the most approved and generally adopted methods in the practice of coal mining. The requests that have been received from publishers of similar technical matter, asking for the privilege of reproducing many of the pages already published in Coal Age, is sufficient evidence of the technical value of the work. Recently, so many letters have come from mining men and from several mining classes who have been studying the pages as they have appeared each week, asking that the matter already prepared be published at once in suitable book form, it has been decided to issue the following sections on the atmosphere, gases and ventilation of mines. Although it is not assumed that these sections are in their final form, they contain much valuable matter that will be appreciated by practical mining men and students of coal mining. Coal Age particularly commends this work to mining students, engineers, mine foremen, assistant foremen and firebosses, superintendents and managers. The book contains only original matter, prepared at great expense of time and labor, involving much careful research and experiment. The author does not hesitate to say that many of the practical problems in the ventilation of mines, which cannot be solved |