Sperry, the author is particularly indebted for an opportunity to examine important papers left by William L. Marcy. Valuable suggestions were most kindly given by Dr. William A. Dunning of Columbia University and Dr. Davis R. Dewey of the Massachusetts Institute of Technology, who read portions of the text, by Francis W. Halsey, Esq., of New York, who read nearly all of it, and by Dr. Edward Charming of Harvard University, who was so good as to look over more or less closely all of the proofs. To the helpers not mentioned by name the author begs leave to offer thanks no less sincere.
Finally, the author desires to mention the enterprise and public spirit shown by the publishers in bringing out so expensive a work at this time of uncertainty.
| The Century Club, New York |
| September, 1919. |
