vi PREFACE 



The authors also wish to take this opportunity to express 

 their appreciation and thanks to those who have so kindly and 

 willingly assisted in the preparation of this work with their 

 suggestions and advice. Among these may especially be men- 

 tioned, Mr. Lewis F. Moody of the I. P. Morris Company; Mr. 

 Chester W. Lamer of the Wellman-Seaver-Morgan Company; 

 Mr. W. A. Doble of the Pelton Water Wheel Company; Mr. A. 

 V. Garratt of the Lombard Governor Company; Mr. J. H. Man- 

 ning of the Stone & Webster Company; and Mr. A. S. Crane of 

 the J. G. White Company. 



ERIC A. LOF 

 DAVID B. RUSHMORE 



SCHENECTADY, 



October, 1917. 



