A TREATISE ON COAL MINING PREPARED FOR STUDENTS OF THE INTERNATIONAL CORRESPONDENCE SCHOOLS SCRANTON, PA. Volume I ARITHMETIC FORMULAS GEOMETRY AND TRIGONOMETRY GASES MET WITH IN MINES MINE VENTILATION MINE SURVEYING AND MAPPING WITH PRACTICAL QUESTIONS AND EXAMPLES Second Edition SCRANTON THE COLLIERY ENGINEER CO. 1900 a Copyright, 1897, 1898, 1899, 1900, Arithmetic Copyright, 1892, 1893, 1894, 1895, 1896, 1897, 1898, 1899, by THE COL- Formulas: Copyright, 1898, 1899, by THE COLLIERY ENGINEER COMPANY. Gases Met With in Mines: Copyright, 1894, 1897, by THE COLLIERY ENGINEER Mine Ventilation: Copyright, 1895, 1897, by THE COLLIERY ENGINEER COMPANY. BURR PRINTING HOUSE, NEW YORK. Zenerablet Skinnet. 12-11-30 64. PREFACE TO SECOND EDITION. The second edition of the Bound Volumes of our Complete Coal Mining Course differs from the first edition in the following respects: All errors, typographical and otherwise, that we have discovered in the first edition have been corrected. In a number of instances we have altered the text somewhat, when by doing so we thought we could make the explanation clearer to the students. We have changed the page numbers in all the volumes except Vols. IV and V, so that each paper and part will begin with 1, instead of numbering the pages continuously throughout the volumes, as in the first edition. In order to make the indexes intelligible we have given each paper and part a number. This number has been placed on the headline of each page opposite the page number; and to distinguish it from the page number it has been preceded by the printer's section mark §. Consequently, a reference such as § 19, page 12, would be readily found as follows: The back stamps on the first three volumes show the sections (i. e., Papers) included in the volumes, that for Vol. II reading § § 11-21; hence, look at the inside edges of the headlines to Vol. II until § 19 is found, and then through § 19 until page 12 is found. The Question Papers have been given the same section numbers as the Instruction Papers to which they belong, and are grouped together at the end of the volume containing the Instruction Papers to which they refer. The Keys have been numbered in the same manner. Since the first edition was issued the following Papers have been added to the Course: Dynamos and Motors |