DEAN OF MECHANIC ARTS
NORTH DAKOTA AGRICULTURAL COLLEGE

First Edition

McGRAW-HILL BOOK COMPANY, Inc.
239 WEST 39TH STREET. NEW YORK


LONDON: HILL PUBLISHING CO., Ltd.
6 & 8 BOUVERIE ST., E. C.

1918

Copyright, 1918, by the
McGraw-Hill Book Company, Inc.


INTRODUCTION