[Illustration: Ericsson’s First Arrangement of Underwater Propeller (Oct. 10, 1834).
Smith’s Amended Specification (May 18, 1839).
Cammerow’s Specification (Dec. 10, 1828).
Specifications of Early Patents taken out in England.]
Three years before (in 1836), a Swede, whose name was destined to become much more famous in our own land, had successfully shown the practicability of screw propulsion, in the Francis B. Ogden, on the Thames. “She was 45 feet long and 8 feet wide, drawing 2 feet 3 inches of water. In this vessel he fitted his engine and two propellers, each of 5 feet 3 inches diameter” (Lindsay). She made ten miles an hour, and showed her capabilities by towing a large packetship at good speed. There was no question of the success of this little vessel, which was witnessed on one occasion by several of the lords of the admiralty. Notwithstanding her unqualified success, Ericsson had no support in England. It happened, however, that Commodore Stockton, of our navy, was then in London; and witnessing a trial of the Ogden, ordered two small boats of him. One, the Robert F. Stockton, was built, in 1838, of iron, by Laird—63 feet 5 inches in length, 10 feet in breadth, and 7 feet in depth. She was taken—April, 1839—under sail, to the United States by a crew of a master and four men. This little vessel was the forerunner of the famous Princeton, built after the designs of Ericsson, who had been induced by Commodore Stockton to come to America as offering a more kindly field for his talents.
In the same year with Ericsson’s trial of the Ogden, Mr. Thomas Pettit Smith took out a patent for a screw; and it was by the company formed by Smith that the screw propeller was first tried on a large scale, in the Archimedes, of 237 tons, in 1839. Of course the names mentioned by no means exhaust the list of claimants to this great invention. Nor can it be said to have been invented by either of these two, but they were the first to score decisive successes and convince the world of its practicability.
In 1770, Watt wrote to Dr. Smalls (who, a Scot, was at one time a professor at William and Mary College, in Virginia, but returned to England in 1785) regarding the latter’s experiments in relation to canal navigation, asking him, “Have you ever considered a spiral oar for that purpose, or are you for two wheels?” In the letter is the sketch, a fac-simile of which is here shown: