There is another technical question to be considered in the fixing of the floats, namely, the fore-and-aft balance of the machine in the air. The propeller of a water-plane has to be set higher than that of a land aeroplane, so that it may not come into contact with the waves. This tends to tip the craft forwards, and thus make the nose of the float dig in the water. To overcome this the float is set well forward of the centre of gravity, and though this counteracts the thrust when the craft "taxies" along the waves, it endangers its fore-and-aft stability when aloft. CHAPTER XXXV. A Famous British Inventor of the Water-plane Though Harry Hawker made such a brilliant and gallant attempt to win the L5000 prize, we must not forget that great credit is due to Mr. Sopwith, who designed the water-plane, and to Mr. Green, the inventor of the engine which made such a flight possible, and enabled the pilot to achieve a feat never before approached in any part of the world. The life-story of Mr. "Tommy" Sopwith is almost a romance. As a lad he was intensely interested in mechanics, and we can imagine him constructing all manner of models, and enquiring the why and the wherefore of every mechanical toy with which he came into contact. At the early age of twenty-one he commenced a motor business, but about this time engineers and mechanics all over the country were becoming greatly interested in the practical possibilities of aviation. Mr. Sopwith decided to learn to fly, and in 1910, after continued practice in a Howard Wright biplane, he had become a proficient pilot. So rapid was his progress that by the end of the year he had won the magnificent prize of L4000 generously offered by Baron de Forest for the longest flight made by an all-British machine from England to the Continent. In this flight he covered 177 miles, from Eastchurch, Isle of Sheppey, to the Belgian frontier, in three and a half hours. If Mr. Sopwith had been in any doubt as to the wisdom of changing his business this remarkable achievement alone must have assured him that his future career lay in aviation. In 1911 he was graciously received by King George V at Windsor Castle, after having flown from Brooklands and alighted on the East Terrace of the famous castle.