HUGH WRIGHT Auditor, Westlake Construction Company. GLENN M. HOBBS, Ph. D. Secretary, American School of Correspondence. JESSIE M. SHEPHERD, A. B. Associate Editor, Textbook Department, American School of Correspondence. GEORGE C. RUSSELL Systematizer. Formerly Manager, System Department, Elliott─Fisher Company. OSCAR E. PERRIGO, M. E. Specialist in Industrial Organization. Author of "Machine─Shop Economics and Systems," etc. DARWIN S. HATCH, B. S. Assistant Editor, Textbook Department, American School of Correspondence. CHAS. E. HATHAWAY Cost Expert. Chief Accountant, Fore River Shipbuilding Co. CHAS. WILBUR LEIGH, B. S. Associate Professor of Mathematics, Armour Institute of Technology. L. W. LEWIS Advertising Manager, The McCaskey Register Co. MARTIN W. RUSSELL Registrar and Treasurer, American School of Correspondence. HALBERT P. GILLETTE, C. E. Managing Editor, _Engineering─Contracting_. Author of "Handbook of Cost Data for Contractors and Engineers." R. T. MILLER, JR., A. M., LL. B. President, American School of Correspondence. WILLIAM SCHUTTE Manager of Advertising, National Cash Register Co. E. ST. ELMO LEWIS Advertising Manager, Burroughs Adding Machine Company. Author of "The Credit Man and His Work" and "Financial Advertising." RICHARD T. DANA Consulting Engineer. Chief Engineer, Construction Service Co. P. H. BOGARDUS Publicity Manager, American School of Correspondence. WILLIAM G. NICHOLS General Manufacturing Agent for the China Mfg. Co., The Webster Mfg. Co., and the Pembroke Mills. Author of "Cost Finding" and "Cotton Mills." C. H. HUNTER Advertising Manager, Elliott─Fisher Co. FRANK C. MORSE Filing Expert. Secretary, Browne─Morse Co. H. E. K'BERG Expert on Loose─Leaf Systems. Formerly Manager, Business Systems Department, Burroughs Adding Machine Co. EDWARD B. WAITE Head, Instruction Department, American School of Correspondence. Authorities Consulted The editors have freely consulted the standard technical and business literature of America and Europe in the preparation of these volumes. They desire to express their indebtedness, particularly, to the following eminent authorities, whose well─known treatises should be in the library of everyone interested in modern business methods. Grateful acknowledgment is made also of the valuable service rendered by the many manufacturers and specialists in office and factory methods, whose coöperation has made it possible to include in these volumes suitable illustrations of the latest equipment for office use; as well as those financial, mercantile, and manufacturing concerns who have supplied illustrations of offices, factories, shops, and buildings, typical of the commercial and industrial life of America.