While the public, after the successful experiments already mentioned, and others which followed, were beginning to appreciate the value of steamers, the Admiralty would have nothing to do with them, and it took them about forty years before they reluctantly applied steam to war vessels. The absolutely first steam vessel built for the Royal Navy was a tug, also named the _Comet_. She was constructed in 1819, after some experiments had convinced Lord Melville and Sir George Cockburn of the value of steam power in towing men-of-war. “At this period, Mr. Ronnie, who planned the breakwater at Plymouth and new London Bridge, was ‘advising engineer’ to the Admiralty, and on every occasion urged the application of steam power to vessels of war. More than this, he hired at his own cost the Margate steam-boat, the _Eclipse_, and successfully towed the _Eastings_, 74, against the tide from Woolwich to Gravesend, June 14th, 1819. On this, the Admiralty, supported by Lord Melville, gave up their objections.”(30) Still, practically, it was not till after the Crimean war that steam became the leading motive power in our war navy. The merchants were more sensible. Mr. David Napier had, in 1818, launched a steamer of ninety tons burden—the _Rob Roy_—from the yard of Mr. William Denny, of Dumbarton. For two years she ran between Glasgow and Belfast, carrying the mails, and was the first regular _sea-going steamer_ which had been built in either Europe or the United States. But she also calls for particular mention for another reason: she was subsequently transferred to the English Channel as a packet-boat between Dover and Calais. And there are still, no doubt, many travellers or residents of those towns who can remember the inauguration of what is now a most important service. The same Napier, whose name is very intimately connected with the history of the marine engine, which he was constantly striving to improve, inaugurated, with the assistance of capitalists, a line between Liverpool, Greenock, and Glasgow. Next followed a line from London to Leith, which commenced with two steamers, each fitted with engines of fifty horse-power. Now came an immense advance, for in 1826, the first of the then considered “leviathan” class of steamers—the _United Kingdom_—was built for the trade between London and Edinburgh. She was 160 feet long, with engines of 200 horse-power. “People flocked from all quarters to inspect and admire her.” [Illustration: THE “UNITED KINGDOM”. (_From a Drawing by E. W. Cooke, R.A._)]