The Lords of the Admiralty made slow progress in adapting the screw for the Royal Navy. Sir William Symonds, the surveyor and principal designer of Her Majesty's ships, was opposed to all new projects. He hated steam power, and was utterly opposed to iron ships. He speaks of them in his journal as "monstrous."[7] So long as he remained in office everything was done in a perfunctory way. A small vessel named the Bee was built at Chatham in 1841, and fitted with both paddles and the screw for the purposes of experiment. In the same year the Rattier, the first screw vessel built for the navy, was laid down at Sheerness. Although of only 888 tons burthen, she was not launched until the spring of 1843. She was then fitted with the same kind of screw as the Archimedes, that is, a double-headed screw of half a convolution. Experiments went on for about three years, so as to determine the best proportions of the screw, and the proportions then ascertained have since been the principal guides of engineering practice. The Rattler was at length tried in a water tournament with the paddle-steamer Alecto, and signally defeated her. Francis Pettit Smith, like Gulliver, may be said to have dragged the whole British fleet after him. Were the paddle our only means of propulsion, our whole naval force would be reduced to a nullity. Hostile gunners would wing a paddle-steamer as effectually as a sportsman wings a bird, and all the plating in the world would render such a ship a mere helpless log on the water. The Admiralty could no longer defer the use of this important invention. Like all good things, it made its way slowly and by degrees. The royal naval authorities, who in 1833 backed the side paddles, have since adopted the screw in most of the ships-of-war. In all long sea-going voyages, also, the screw is now the favourite mode of propulsion. Screw ships of prodigious size are now built and launched in all the ship-building ports of Britain, and are sent out to navigate in every part of the world. The introduction of iron as the material for shipbuilding has immensely advanced the interests of steam navigation, as it enables the builders to construct vessels of great size with the finest lines, so as to attain the highest rates of speed.