"A critical study was made of the operation of a type of back-fire arrester used to reduce the fire hazard of aircraft engines. A flame arrester consisting of a pack or plug of alternate flat and corrugated plates of thin metal was installed in the intake pipe of a gasoline engines; an auxiliary spark plug inserted in the intake manifold permitted the production of artificial back fires at will. It was found possible to design a plug which prevented all back fires from reaching the carburetor" (p. 211).

"This report presents a comparison of superchargers on the basis of the power required to compress the air at a definite rate, and on the basis of the net engine power developed at altitudes from 0 to 40,000 feet. The investigation included geared centrifugal, turbine-driven centrifugal, roots, and vane-type superchargers. It also includes a brief discussion of the mechanical limitations of each supercharger and explains how the method of control affects the power requirements" (p. 425).