Ericsson applied this invention to the _Francis B. Ogden_, which was built in 1837. She was 45 feet long, and was driven by a two-cylinder steam engine with a boiler pressure of 50 lb. The result of the experiment showed that she could tow a vessel of 630 tons burthen at 4½ knots against the tide. The following year a larger vessel, the _Robert F. Stockton_, was built by Laird Brothers, and attained a speed of thirteen knots on the Thames, with the tide in her favour. Afterwards she crossed the Atlantic, but under canvas, and was turned into a tug as the _New Jersey_, for work in New York waters. The illustration facing page 120, which has been lent by Messrs. Cammell, Laird and Company, Limited, of Birkenhead, shows her rigged as a topsail schooner under sail and steam. Her measurements were 63.4 feet long, 10 feet beam, 7 feet deep, with a register of 33 tons, and engines of 30 horsepower. Although she was the first screw steamer to cross the Atlantic, yet her voyage is interesting rather as a fairly daring trip of a small sailing ship than as proving the reliability of the screw propeller. But at the same time that Ericsson was working at his idea, Francis Smith, an Englishman, who was afterwards knighted, was also engaged at the same problem, though his method of solution was of a different nature, as will be seen by a reference to the last illustration on the first line of the plate facing page 118. His patent was granted in the same year as Ericsson’s, and was tried with success the year after on the Paddington Canal. Smith was a farmer at Hendon, and had already experimented with a model driven by clockwork on a farm pond, just as Fulton had carried out his early experiments with a clockwork model in a tank. The next step was to repeat the experiment on a six-ton boat which was driven by a steam engine, the propeller being, like those of the modern aeroplanes, of wood. It was while thus experimenting that an interesting accident happened, for about one-half of the screw thus shown in the illustration was broken off, and to everyone’s surprise the boat instantly began to leap forward at a quicker speed. Later the boat was fitted with a screw having one turn instead of two, and made of metal instead of wood, and in this small craft Smith cruised as far as Folkestone. Her speed was 5½ knots. [Illustration: THE “ROBERT F. STOCKTON” (1838). _Photograph supplied by Messrs. Cammell, Laird & Co., Limited, Birkenhead._] [Illustration: THE “ARCHIMEDES” (1839). _From a Contemporary Print._]