UNIVERSITY OF WISCONSIN EXTENSION TEXTS A series of Industrial and Engineering Education Textbooks, developed under the direction of Dean LOUIS E. REBER, University of Wisconsin Extension Division Dean of Engineering, University of Montana; Formerly Professor AND KENNETH G. SMITH, A. B., B. S. State Supervisor of Industrial Education, Lansing, Michigan; Formerly SECOND EDITION MCGRAW-HILL BOOK COMPANY, INC. NEW YORK: 370 SEVENTH AVENUE COPYRIGHT, 1913, 1924, BY THE PRINTED IN THE UNITED STATES OF AMERICA THE MAPLE PRESS COMPANY, YORK, PA. PREFACE TO SECOND EDITION In bringing out a second edition of Shop Arithmetic, sincere gratification is expressed for the reception accorded the first edition which ran through seventeen impressions. Twelve years ago there was great need for a plain, practical, interesting text of this kind. The University Extension Division of the University of Wisconsin, for lack of such a book, was obliged to produce this volume in connection with its work. Immediately upon its publication many other Extension Divisions adopted and used the book both for correspondence and class instruction. It has likewise been widely used in trade, continuation, shop, apprentice, and other schools of like character. This extensive use with extraordinary variations in student types has resulted in practical suggestions for change and improvement that have been incorporated in the present revision. Two entirely new chapters have been added to the book, one on Logarithms and one on the Slide Rule. This additional text material has been found to be desirable particularly for those students who plan to go forward with subsequent studies in industrial or engineering courses. Mr. Herbert E. Schrader, while instructor in Mechanical Engineering in the University Extension Division, prepared both the new material and the text of the revision. He is to be commended upon the success he achieved in incorporating the newer ideas and later practices in the spirit of the original work. Much valuable assistance and counsel were given by Mr. W. E. Wines and Mr. Herbert B. Byrn of our present staff. Due acknowledgment is also made to the many users of the first edition who made valuable suggestions and contributions towards this revision. It is hoped that this new edition will commend itself to old friends and win new ones. BEN G. ELLIOTT. Professor of Mechanical Engineering MADISON, WISCONSIN June, 1924. |