There is an old saying in the aircraft industry that you can make a brick fly, if you give it enough power. How true this is I would not care to say, but it is certainly true that the worries of the designer are lessened if he knows that he can always give the throttle a little extra push, if all else fails.

This is not to say that the design of a conventional, high powered, aircraft is a simple, hit or miss affair, that would be ridiculous, but it does serve to show the special difficulties faced by the builders of a man-propelled aircraft who have less power available to them than is used by a small electric fire.