Engineering Wonders of the World
Volume III

AERONAUTICAL ENGINES. 31 Fig. 1.—THE WRIGHT FOUR-CYLINDER 35 HORSE-POWER ENGINE. {Photo, Topical.} magneto driven off the cam shaft. On the farther side of the crank-case is a small worm- gear driven pump, which delivers petrol direct into the cylinders, and a pump for forcing lubricating oil from a reservoir in the bottom of the crank-case through the main bearings. A very simple radiator, of flat copper tubes, is mounted ver- tically on one of the stanchions separating the decks. It is to the credit of the Wrights that they designed and built the first petrol engine ever used for mechanical flight. So far, they have not, apparently, seen any good reason for abandoning the simple type with which they won their first successes. The Green engine, built for the Green Motor Patents Syn- dicate by the Aster Engineer- ing Company, has, in addition to the fact that it is one of the at present very few British- made aeronautical engines, sev- eral interesting points. It is extremely light in proportion to its power. The nominal 35 The Qreen . Engine. horse - power type (Fig. 2) scales but 148 lbs., so averaging about 4 lbs. to the horse-power, fly-wheel included; the 60 horse-power model weighs 236 lbs. Light- ness has been obtained without sacrificing strength by very careful design. The cylinders and valve ports are cast in high-grade steel, and machined inside and out to the maximum thinness advisable. The water jacket, pressed out of thin copper sheet, encloses com- pletely the upper part of the cylinder and valves. A grooved flange projects from the cylinder to accommodate a rubber ring, against which the slightly bell-mouthed open end of the jacket presses, and so a water-tight joint is obtained. The heat of the engine has no effect on the