In writing this book I have been not only introducing new ideas and new methods of analysis, but I have been using a tongue new to me. The original manuscript was very crude and foreign in form, and I am greatly indebted to various friends for their patient kindness in correcting the many errors of my poor English.
I am also under great obligations to Walter Polakov, Doctor of Engineering, for his exceedingly helpful suggestions, not only in giving me a thorough criticism from the point of view of the Engineer, but also in devoting his energies to organizing the first “Time-binding Club” where these problems have been discussed and criticized, with great practical results.
To all those who have read and criticized the manuscript or helped otherwise—Professors E. H. Moore, C. J. Keyser, J. H. Robinson, Burges Johnson, E. A. Ross, A. Petrunkevitch; and Doctors J. Grove-Korski, Charles P. Steinmetz, J. P. Warbasse; Robert B. Wolf, Vice-President of the American Society of Mechanical Engineers; Champlain L. Riley, Vice-President of the American Society of Heating and Ventilating Engineers; Miss Josephine Osborn; to the authors, L. Brandeis, E. G. Conklin, C. J. Keyser, J. Loeb, E. S. Mead, H. O’Higgins, W. Polakov, J. H. Robinson, R. B. Wolf, for their kind permission to quote them, I wish to express my sincere appreciation.
I wish also to acknowledge the deepest gratitude to my wife, formerly Mira Edgerly, who has found in this discovery of the natural law for the human class of life, the solution of her life long search, and who, because of her interest in my work, has given me incomparably inspiring help and valuable criticism. It is not an exaggeration to state that except for her steady and relentless work and _her time, which saved my time_, this book could not have been produced in such a comparatively short time.
Mr. Walter Polakov of New York City, Industrial Counsellor and Industrial Engineer in New York City, has kindly consented at my request to act, with my authority, as my representative to whom any further queries should be addressed in my absence from America.
To all other friends who have helped in many personal ways I express thankfulness, as I wish also to thank John Macrae, Esq., the Vice-President of E. P. Dutton & Co., for his unusual attitude toward publishing the book.