The main object of this paper is to show the importance of supercharging, the desirable results brought about by the process, and a consideration of the difficulties.

Supercharging, as understood by aeronautic engineers, is the process whereby the output of an engine at sea level is maintained at altitudes. Forced induction, by means of a rotary blower, has however been tried on automobile engines. Only one maker, Mercedes, has so far incorporated this feature in the standard design. This practice has much to be said for it, as a small engine may be made to give a large output without running abnormally fast, or resorting to special fuel.

It would be interesting to consider the application of superchargers to aero engines with this idea of obtaining large outputs from small engines. Given good design, an actual increase in horse-power for a given weight would result.