to preserve order. She steamed into harbour, with wind and tide, at from twelve to fourteen knots. A court-martial was sitting in the _Gladiator_ frigate, but the whole court except the president adjourned to inspect the strange visitor. Next day the port admiral sent off a guard and band; and soon afterwards he followed, accompanied by three admirals, eighteen post captains, and a large number of ladies.[142] The success of the _Thames_ led to the immediate building of other and larger steamers. In ’17 the son of James Watt purchased a 94-foot boat, the _Caledonia_, fitted her with 28-horse-power machinery driving 10-foot paddlewheels, and for a pleasure trip proceeded in her up the Rhine as far as Coblentz. From this time onwards steam navigation for commercial purposes progressed rapidly. In 1818 a steamboat made regular voyages at sea; the _Rob Roy_, 90 tons, built by Denny of Dumbarton, with engines of 30 horse-power made by Napier, plied regularly between Holyhead and Dublin. In the same year the _Savannah_, a ship of 350 tons’ burden built and fitted with auxiliary steam machinery at New York, crossed the Atlantic, partly under steam; her paddlewheels with their cast-iron frame and axletree successfully withstanding heavy weather. In ’21 the postmaster-general introduced a steam service for the mails at Dover and Holyhead; and in the following year there were steamboats running between London and Leith, and other seaports. The experience of the Holyhead packets was of special value, as it proved that steam vessels could go to sea in weather which would keep sailing vessels in harbour. Soon after this the question was raised of employing steam power to shorten the passage between England and the East, as well as of the navigation by steam of the great Indian rivers. Steam superseded sails in the government mail service between Falmouth, Malta and Corfu; everywhere commercial enterprise was planning new lines of steamships and new possibilities of ocean travel. In ’25 a barque belonging to Mr. Pelham, afterwards Earl of Yarborough, was fitted with steam machinery as an auxiliary and made the voyage to India. The plash of the paddlewheel was then heard for the first time in Oriental waters. By this time the great question of steam as applied to naval ends had arrived to agitate the Admiralty.