ENGINE power is an expression that has a wide range of meaning. In its most fundamental sense, it is the capacity for doing work developed in the engine cylinders and is limited by the breathing capacity of the engine, that is, its rate of air consumption. The author describes a positive rotary-displacement measuring apparatus designed to overcome the objections often raised to the use of the customary type of air-meter in the induction system. The contribution describes a method for attaining greater accuracy or simplicity of operation evolved in the course of an investigation, and the method described is easily applicable by others who may have similar problems requiring solution.
