iv PREFACE. 



The present book is a result of two years experience as designing 

 engineer and contracting agent for the Gillette-Herzog Mfg. Co., Min- 

 neapolis, Minn., and four years experience in teaching the subject at 

 the University of Illinois. This book represents the course given by the 

 author in elementary stresses and in the design of metal structures, pre- 

 liminary to a course in bridge design. While written primarily for the 

 author's students it is hoped that the book will be of interest to others, 

 especially to the younger engineers. 



As far as practicable credit has been given in the body of the 

 book for drawings and data. In addition the author wishes to 

 acknowledge his indebtedness to various sources for drawings and 

 information to which it has not been practicable to give proper 

 individual credit. He wishes to thank Messrs. C. W. Malcolm, 

 L. G. Parker and R. H. Gage, Instructors in Civil Engineering in 

 the University of Illinois, for assistance in preparing the drawings, 

 especially Mr. Malcolm who made a large part of the drawings. 



The author will consider it a favor to have errors brought to his 

 notice. 



Champaign, 111., M. S. K 



August 17, 1903. 



PREFACE TO THE SECOND EDITION. 



In this enlarged edition more than 100 pages of new material, in- 

 cluding many cuts, have been added. The additions include a discussion 

 of influence diagrams ; the calculation of stresses in pins ; a chapter 

 on " Graphic Methods for Calculating the Deflection of Beams " ; data 

 on loads, foundations, and saw-tooth roofs; descriptions of^various 

 buildings ; and an appendix giving the analyses of 22 Problems in 

 Graphic Statics. 



The author wishes to acknowledge the appreciation with which 

 the first edition was received by engineers and instructors. 



Boulder, Colo., M. S. K. 



June i, 1906. 



