Show airplanes and boomerangs it seems a downright anomaly to po irn to the primitive inhabitants of australia for points on an airplane yet that Is precisely what was adno if no at one stage of the development ot of aviation the fundamental principle of the airplane Is both old and simple 4 having g been discovered by the bush men of the antipodes and embodied by then them in tile alie boomerang which by meeting in its flight the air at a slight angle got a lift the trajectory of the boomerang may be in it part horizontal or muy may even rise as a result of this lift any surface that Is more or less flat which travels at a slight angle through the air tends to lift if tile lie section lias has a all blight lit camber or convex curve cume the lift 1 Is increased letter better results are obtained it a body of appreciable thickness Is used instead of a thin sheet investigation will reveal little liitle differ eiKe eme between th wing section of a boomerang ninde made by the he bushmen or whittled by an american boy after lie he has visited tile the circus and has witnessed n sed the stunts of the boomerang t thrower ronn er |