That Robert Fulton devoted some attention to the possibility of an underwater boat during the years when his mind was laboring with plans for the propulsion of boats by steam, has been known since that time. Not, however, until 1896, did it become clear to what extent he had carried his ideas. In that year Lieut. Emile Duboc discovered in the Archives Nationales in Paris the full account of Fulton’s negotiations with the French Government and the plans of the boat that he had constructed, and in which he actually plunged. Other investigators, chiefly Lieut. Maurice Delpeuch of the French navy and Mr. S. L. Pesce, have made public this interesting record. To their respective treatises, “Les Sous-Marines À travers les SiÈcles” and “La Navigation sous marine” the author of this book is indebted for much information.

It was also known that Fulton left France for England in 1804 presumably to work for the government of the latter country in the development of torpedoes. It has been supposed that he made some suggestions for a submarine, suggestions that were not taken seriously. His first biographer, Cadwallader D. Colden, and his own published writings make no reference to an underwater boat. But such a boat was the basis and essence of his work and not merely an incidental suggestion. The lack of knowledge and consequently the erroneous supposition are due to the fact that what he actually proposed to the government was purposely kept secret for political reasons. A manuscript wholly in Fulton’s handwriting, signed in three places, and large, carefully executed water-colored drawings made and each signed by him have recently been found in England. This manuscript and drawings show that the main idea that he laid before the British Government was a sea-going submarine vastly superior to the one that he had previously submitted to the French authorities. The manuscript and other substantiating documents and letters that have been examined prove clearly that it was alarm on the part of the British Admiralty regarding his initial French submarine that led the government to induce Fulton to go to England and place himself and his devices unreservedly at their service.

This record, now published for the first time, shows that Robert Fulton was unquestionably the first one to design a practical vessel capable of submerging and rising at will, that could keep the sea for an extended period of time with a large crew, and that could be propelled either on or beneath the surface, or that could lie safely at anchor under either condition. The record also shows that Fulton foresaw with extraordinary clearness conditions that might arise, and which actually did come to pass in the great war recently ended.

Fulton’s manuscripts and letters are reprinted exactly as he wrote them so far as access has been had to the originals, words that he erased are enclosed in brackets. Some of his letters taken from books have evidently been corrected in their orthography before publication. In such cases the published text has been followed.

In the preparation of this book the author has been assisted, and for which assistance he makes grateful recognition, by Mrs. Alice Crary Sutcliffe and Mr. Edward C. Cammann, descendants of Mr. Fulton, who have kindly placed at the author’s use their great grandfather’s papers; by Mr. L. F. Loree who did the same with his collection of Fultoniana; by the British Ambassador who procured a search of the British Government records, and by the New Jersey Historical Society. The author has drawn from a number of works on Fulton, particularly the biography by Colden (1817) and “Robert Fulton” by H. A. Dickenson (1913), as well as the French volumes above mentioned.