viii PREFACE. 



by Franklin and Esty, S. P. Thompson, and Samuel Sheldon, or 

 with an introductory text such as that by H. H. Norris. The 

 experiments given in the book may be supplemented by others of 

 an elementary, intermediate or advanced nature, as circumstances 

 may require. The division of experiments into parts and sections 

 will be found to add materially to the flexibility of the book. 



The author desires to express his appreciation of the initial 

 instruction and inspiration of Professor H. J. Ryan and of the 

 continuous cooperation for many years of Professor G. S. Moler. 

 He wishes also to express his indebtedness to many who have been 

 associated with him in laboratory instruction, in particular to Dr. 

 A. S. McAllister, as many references in the present text bear evi- 

 dence. He likewise desires to express his appreciation of the 

 spirit of cooperation shown by Professors H. H. Norris and V. 

 Karapetoff and other engineering colleagues. The author is in- 

 debted, furthermore, to various professors and students, who 

 have used and corrected this book in proof during the last year 

 and to a number of engineers who have looked over the proof 

 sheets and have made valuable suggestions. For all shortcomings 

 the author alone is responsible. 



ITHACA, N. Y., July i, 1909. 



