Samuel Pierpont Langley

Date: Born on August 22,1834, in Roxbury, Massachusetts; died on February 27, 1906, in Aiken, South Carolina
Definition: Late nineteenth century American scientist who made important contributions to aerodynamics, astrophysics, and meteorology.
Significance: Through pioneering research in aerodynamics, Langley established the principles of flight and demonstrated the practicability of mechanical flight with self-propelled heavier-than-air machines, building a steam-powered model aircraft that flew in 1896 and a gasoline-powered aircraft that flew in 1901.
Born in 1834, Samuel Pierpont Langley concluded his formal education upon graduation from Boston High School. He then worked for several architectural firms while pursuing his passion for building telescopes. The latter skill led to several academic appointments, culminating in 1867 with a post at Western University in Pittsburgh, Pennsylvania, where for twenty years Langley taught and was the director of the Allegheny Observatory. Langley made landmark contributions to the study of sunspots and invented the bolometer, a device to measure infinitesimal temperature variations across the light spectrum. In 1881, he led an expedition to Mount Whitney, California, to measure the amount of heat received from the Sun by Earth’s atmosphere, apartially successful effort that resulted in the unit of measure named after him.
Langley’s study of aerodynamics began shortly before his appointment in 1887 as secretary of the Smithsonian Institution, a position he held until his death. Throughout the early 1890′s, Langley built successive models of what he called “aerodromes,” uncrewed flying machines driven by gasoline-fueled, steam-powered engines. He launched his aerodromes from a track atop a houseboat on the Potomac River near Quantico, Virginia. On May 6, 1896, his 16-foot-long aerodrome model number 5 was catapulted out and flew for 90 seconds over a range of 3,000 feet. This epochal event marked what was arguably the first sustained flight of a heavier-than-air craft.
Although Langley intended to set aside aeronautical work after that success, he was persuaded by President William McKinley to develop a crewed craft in 1898. When European firms could not supply a suitable engine, Langley’s assistant, Charles Manly, built a light but powerful internal combustion engine. In 1901, an uncrewed aerodrome model using such an engine became the first gasoline-powered vehicle to fly. A houseboat rigged with a cumbersome 85-foot-long track on its roof served as the launch for the 850-pound crewed machine, which Manly piloted. When it was launched on October 7, 1903, 40 miles south of Washington, D.C., it became caught in the launch mechanism and plunged overboard. A similarly disastrous second launch was attempted nearer the city on December 8, 1903. Nine days later, Orville and Wilbur Wright, operating independently of Langley and without government aid, made a successful flight at Kitty Hawk, North Carolina. Langley, discouraged by his failures, died of a stroke on February 27, 1906.
Langley’s successor at the Smithsonian, Dr. Charles Walcott, in 1914 enlisted aviation pioneer Glenn H. Curtiss to reconstruct the 1903 Langley machine and launch it from pontoons. The effort was successful, but the revisions made by Curtiss as well as Curtiss’s own financial interest in undermining the Wright brothers’ aircraft patents, leave open the question whether Langley’s original craft might have flown had it not been for his unfortunate launch mechanism.