In the present case, as we have noted above, the question is not so much one of invention as of influence in introduction, adaptation, and improvement.  The screw-propeller was already known, but had not been introduced into and made a part of actual engineering practice.  Services in this direction are all that can be claimed for any of those concerned with the question during the third decade of the Nineteenth Century.  From this point of view we must give to Ericsson large credit.  He had the courage of his convictions, and did not allow his work in this direction to lapse for lack of effort on his part to secure its introduction into the practice of the day.

Thus, in 1837, the “Francis B. Ogden” was built for the special purpose of testing the power of the screw-propeller, and was operated on the Thames for the benefit of the British Admiralty and many others.  Shortly after this, and largely through the influence of Capt.  Robert F. Stockton of the American Navy and Francis B. Ogden, the American Consul at Liverpool, Ericsson began to consider a visit to the United States for the purpose of building, under Stockton’s auspices, a vessel for the United States Navy.  While these negotiations were under way, in 1838, he built for Captain Stockton a screw-steamer named the “Robert F. Stockton,” the trials of which attracted much attention from the public at large and from engineers of the time.  At about the same period Ericsson’s propeller was fitted to a canal-boat called the “Novelty,” plying between Manchester and London.  This was presumably the first instance of a screw-propeller employed on a vessel actually used for commercial purposes.

Finally, in pursuance of Ericsson’s plans with Captain Stockton, he left England Nov. 1, 1839, and started for New York in the steamer “Great Western,” where he arrived November 23, after a long and stormy passage.

We now reach the final scene of Ericsson’s life and professional activities.  His visit was at first intended only as temporary, and he seems to have anticipated an early return after carrying out his plans with reference to a ship for the United States Navy.  To quote from a letter to his friend, Mr. John O. Sargent, he says:  “I visited this country at Mr. Ogden’s most earnest solicitations to introduce my propeller on the canals and inland waters of the United States.  I had at the same time strong reasons for supposing that Stockton would be able to start the ‘big frigate’ for which I had prepared such laborious plans in England.”  The event was otherwise determined, however, and during the remaining fifty years of his life he lived and wrought in the New World, and as a citizen of his adopted country.

If the record of his twelve years of work in London was long, that for the remaining and maturer years of his life may well be imagined as vastly greater.  During the earlier part of this period, or until the Civil War, when all his energies were concentrated upon his work in connection with the “Monitor” type of warship, we find the same wealth of invention and human energy, but for the most part directed along lines related to marine and naval construction.  It was a period of training for the fuller fruitage of his genius during the Civil War.