Samuel Pierpont Langley (1834-1906), an American astrophysicist and astronomer who was a pioneer in the measurement of the solar constant and the study of the infrared portion of the solar spectrum. In the late 1870s, Langley developed the bolometer, a device capable of accurately measuring thermal radiation. Langley's bolometer was so sensitive that it could detect the thermal radiation from a cow from a quarter of a mile away. His first “map” of the infrared portion of the solar spectrum was published in 1894. In the 1880s, Langley became interested in the prospect of heavier-than-air flight. With a grant from the United States War Department, he built a full-sized aerodrome, the 'Aerodrome A', with a gas-powered engine. In 1903, the Aerodrome A crashed immediately after being launched from a houseboat over the Potomac River; it was too heavy to fly. Langley did not make another attempt at flight. A few days later on December 17, 1903, the Wright brothers successfully flew the first powered, manned flight. While the Wright brothers were recognized as “first in flight", Langley is credited with influencing their achievements and with helping establish the United States as a leader in aerodynamic research.
- Efforts at Powered Flight During the Last Decade Before the Wright Brothers, U.S. Centennial of Flight Commission.
- Langley, Samuel Pierpont. Story of Experiments in Mechanical Flight, "To Fly is Everything..." virtual museum.
- Samuel Pierpont Langley biography, FlyingMachines.org.