IT was but natural that in his presidential address to the Institution of Mechanical Engineers on October 22, Sir J. E. Thornycroft should deal with the development of torpedo craft. He was a child five years of age when at Chiswick his father, Sir J. I. Thornycroft (1843–1928) built the Lightning, the first torpedo boat in the British Navy, and he has thus witnessed the growth in size, speed and power of torpedo boats, torpedo boat destroyers and the newest motor torpedo boats. Together with Sir Alfred Yarrow and Jacques-Augustin Normand, of Havre, Sir J. I. Thornycroft was a pioneer of water-tube boilers, forced-draught and high-speed engines, and from the works he founded at Chiswick and Woolston have come many of the most notable vessels ever launched. Towards the end of his address, Sir John Thornycroft made some interesting observations on the skimming principle applied to boats, and on the need for simplification in warships. As is well known, the motor torpedo boat, first brought into use in the Great War, is of such a design that when sufficient speed is attained it skims or planes along the surface of the water. Some people think the principle might be applied to larger vessels, but Sir John pointed out that whereas a 50-ft. motor-boat will skim at 30 knots, a 300-ft. destroyer would have to attain a speed of 70 knots, and this would necessitate engines of 200,000 horse-power. Apart from the propelling machinery, ships to-day are filled with mechanism. The very complexity of this raises the question as to means by which it is to be kept in order, and this led to the suggestion that the work of mechanical engineers should be in the direction of simplification.