The Bureau of Mines, in carrying out one of the provisions of its organic actto disseminate information concerning investigations made-prints a limited free edition of each of its publications. When this edition is exhausted, copies may be obtained at cost price only through the Superintendent of Documents, Government Printing Office, Washington, D. C. The Superintendent of Documents is not an official of the Bureau of Mines. His is an entirely separate office and he should be addressed: SUPERINTENDENT OF DOCUMENTS, The general law under which publications are distributed prohibits the giving of more than one copy of a publication to one person. The price of this publication is 35 cents in paper cover. First edition. October, 1918. CONTENTS. Legislation for safety of miners----- Constitution requires laws protecting miners__. Construction of constitutional provision-Classification. Statutes complying with requirements-Construction. Page. |