In 1789, a sixty-feet boat was driven for nearly seven miles an hour with a twelve horse-power engine, but for a very long time nothing was expected except canal work and towing. Even as steam progressed, it did so in the merchant service first. By the year 1818, however, the Americans had built a sea-going steamer, _Savannah_, which crossed the Atlantic to Russia. On her return voyage the United States was reached twenty-five days after leaving Norway. In England, in the year 1821, a steam mail service, between Holyhead and Dublin, was established, and in 1823 a steam mail service between England and India was seriously asked for, and in 1829 the subject again came upon the _tapis_. In 1839, the steam liner _Great Britain_, was laid down. She was 322 feet long overall and a beam of fifty-one feet, and a displacement of 2,984 tons, with 1,000 horse-power. It was originally intended to make her a paddle-vessel. Instead of that, however, she was made a screw-steamer, and made her first trip in December, 1844, when she succeeded in exceeding her anticipated speed. This serious attention to steam in the mercantile marine naturally attracted considerable interest in the Navy, the more so as two naval officers, Captains Chappel and Claxton, were the principal promoters of the mercantile enterprises. It was, however, generally pointed out that useful as steam might be for such purposes, it was unsuitable for warships proper, on account of the liability of the machinery to damage, and the practical impossibility of combining paddles with sailing. It was laid down that the first essential of a warship was to be able to sail, that if steam power could be usefully applied as an auxiliary it might be “desirable.” After considerable experiments and investigations, it was found possible to place the machinery under the water-line, but the paddle-wheels were still exposed, and the armament space available was so slight that steam did not gain much favour. The first steam vessel actually brought into the British service was the _Monkey_, built about the year 1821. She was bought into the service and used as a tug. In the following year, the _Comet_ was specially built for the packet service,[82] but none of these were steam warships. In 1843, the success of the _Great Britain_ influenced the Admiralty, and the _Penelope_ (forty-six) was cut apart and lengthened by sixty-five feet, and had engines of 650 horse-power fitted to her. In 1844, the Earl of Dundonald (Cochrane) submitted plans to the Admiralty for a steamer of 760 tons, called the _Janus_. This vessel was built with an engine of his own design, but as this was a failure, ordinary engines were fitted. In all these steamers the gun-fire was chiefly end-on, but in 1845 the _Odin_ and the _Sidon_, especially designed for broadside fire, were put in hand.