Coal will continue to provide a major portion of energy requirements in the United States for at least the next several decades. It is imperative that accurate

-1898 include also the reports of the State Inspectors of Mines; 1899-1907, Report of the Illinois Free Employment Offices; 1917- , reports of the Miners' Exami

This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant mark