All About Engines

224 All About Engines usually by a two-cylinder two-stroke engine. As the air flung back by the propeller passes over the engine the cylinders do not need to be water-jacketed, but they are provided with fins to increase the cooling surface. Engines for Aeroplanes The aeroplane engine is nothing more or less than a motor-car engine in which the highest quality of material and workmanship is combined with the lightest possible construction. When Professor S. P. Langley, of the Smithsonian Institution, Washing- ton, made his memorable experiment on mechanical flight in 1896, the lightest steam engine he could construct contained sufficient fuel and water for a journey of one and a half minutes. At the end of that period the model aeroplane sank slowly on the waters of the Potomac, where the experin^nt was tried. In 1897 Ader, a Frenchman, succeeded in flying about 300 yards, but this remained un- noticed until flying became almost an everyday matter. The brothers Wright flew 200 yards in 1903 and from eleven to thirty miles in 1906. From that year flying on machines heavier than air passed out of the region of occasional experiments into that of regular practice, though apart from the achieve- ments of the Wrights the distances were never more than a few hundred yards. In these early days, as now, nearly everything depended upon the motor. The Wrights made their own, and so did Glenn Curtiss, who won the speed