Charles M. Olmsted, a European trained physicist from Upstate New York, had an interest in flight from his early years. His success with gliders in the 1890's led to the formation of the Buffalo-Pitts-Olmsted Syndicate in 1910 to develop aircraft. Following failure of the related agricultural equipment manufacturing company, Olmsted formed the CMO Physical Laboratory, continuing to manufacture and sell his ultra-efficient propellers. Olmsted designs differed from other propellers, having a large surface near the blade base and very little surface at the tip. Olmsted's propellers represented a fundamental difference in design philosophy that has not been duplicated by any other designer.
Although intended for a Curtiss Flying Boat in 1915, this left-turning pusher propeller was apparently for test purposes or a factory reject, as the hub is very narrow and it was never finished. Aviation pioneer Glenn Curtiss, who broke world payload records in 1914 with Olmsted propellers, stated they were the best he had ever flown.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.