Like the Wright brothers, who followed, John Stringfellow and his associate William Henson are an important link to early aeronautical researchers. At an exposition in 1868 in London's Crystal Palace, where it powered a triplane model along a cable, the Aeronautical Society of Great Britain awarded a prize of £100 to Stringfellow’s engine as the lightest in proportion to its power, producing 0.75 kW (one horsepower) for the weight of 5.9 kg (13 pounds).In 1889, Smithsonian Secretary Samuel P. Langley purchased the engine, along with a "car" designed to carry an engine and a pair of propellers, for £25. Langley held on to the engine briefly, sending it to L.D. Copeland of Smithville, N.J., for experimental work. Upon return of the engine to Langley, he turned it over to the museum section of the Smithsonian for public display, also in 1889.