Collection Item Summary:
An early manufacturer in the United States, Spencer Heath's American Propeller and Manufacturing Company opened in Baltimore in 1909. Heath was first to use machines for mass production of aircraft propellers, which, under the Paragon trademark, were widely used in World War I. Like most propellers of that era, construction was a wood laminate because of light weight, strength, fabrication ease, and resistance to fatigue in a vibrating and flexing environment.
Heath demonstrated his "engine-powered, engine-controlled, variable and reversible pitch propeller" in 1919, but was unsuccessful in convincing the Army of the practicality of his design. He sold the company to the Bendix Corporation in 1929 and retired from aeronautics two years later.
The manufacturer's brochure states: "Four-bladed propellers have a useful field where the diameter is greatly restricted and large power must be transmitted with small diameter."