Samuel Langley

Samuel Pierpont Langley: The Scientist Who Lost the Sky

On 7 October 1903 the Secretary of the Smithsonian Institution watched his life's ambition drop off a houseboat catapult on the Potomac and go into the water, in the phrase of one witness, "like a handful of mortar." He tried again on 8 December. The machine disintegrated as it left the rail. Nine days later two bicycle mechanics from Dayton got off the ground at Kitty Hawk, and Langley's name passed permanently into the column marked "almost." It was an unjust fate for a man whose other invention could detect a temperature change of one hundred-thousandth of a degree.

No Degree, a Library Card

He was born on 22 August 1834 in Roxbury, Massachusetts, attended Boston Latin School and graduated from the English High School of Boston, and that was the end of his formal education. There was no university, no doctorate, no apprenticeship to a great man. He read his way into science through Boston's libraries, worked as a civil engineer, and eventually talked his way into a job as an assistant at Harvard College Observatory. From there he moved to the United States Naval Academy as a nominal professor of mathematics whose actual assignment was to put the Academy's derelict observatory back into working order.

The Observatory That Sold Time

In 1867 he became director of the Allegheny Observatory and professor of astronomy at the Western University of Pennsylvania, later the University of Pittsburgh. The observatory was broke. Langley's solution was one of the more inventive pieces of scientific entrepreneurship of the century: he built the Allegheny Time System, a set of precise timekeeping standards — including time zones — distributed over 4,713 miles of telegraph line to railroads across the United States and Canada, and sold the service. The revenue kept the observatory running until 1883. Astronomers had always kept the time; Langley worked out how to bill for it.

He also drew. His 1873 rendering of a sunspot, made with the observatory's thirteen-inch telescope, remains one of the most reproduced images in the history of solar astronomy.

An Instrument That Could Feel a Hundred-Thousandth of a Degree

In 1878 Langley built the bolometer, and it changed what could be known about radiation. The device was almost insultingly simple in description — two thin strips of metal, a Wheatstone bridge, a battery, and a galvanometer — and staggering in performance: it could register temperature differences of one hundred-thousandth of a degree Celsius. With it he pushed measurement deep into the infrared, mapping the intensity of solar radiation across bands nobody had been able to reach, and pursued the question that occupied him for decades — how much energy the sun actually delivers to the Earth, and what that means for weather and life.

The consequences ran far beyond his lifetime. His infrared measurements of atmospheric carbon dioxide were the data Svante Arrhenius used in the calculations that founded greenhouse-effect science. NASA's Earth Radiation Budget Experiment and its Clouds and Earth's Radiant Energy System instruments are the bolometer's direct descendants, still measuring what Langley set out to measure.

Secretary of the Smithsonian

In 1887 he became the third Secretary of the Smithsonian Institution, a post he held until his death, and founded the Smithsonian Astrophysical Observatory. He now had a national platform, and he used it to pursue something no respectable scientist of his generation would touch.

The Aerodromes That Flew

Langley was almost alone among professional scientists in believing that mechanical flight was possible. He did the work systematically: measuring lift and drag, explaining the mechanics of soaring birds, building steam-powered unpiloted models he called aerodromes. On 6 May 1896 Aerodrome No. 5, a 25-pound machine, made flights of 2,300 and 3,300 feet — roughly ten times anything previously achieved by a heavier-than-air craft. On 11 November the same year, Aerodrome No. 6 covered more than 5,000 feet. Rudyard Kipling, who met him, remembered "an old man who had designed a model aeroplane driven... by a miniature flash-boiler engine" that "flew on trial over two hundred yards, and drowned itself in the waters of the Potomac."

He understood things his contemporaries did not. In 1902 he articulated the counter-intuitive consequence of induced drag: "A plane of fixed size and weight would need less propulsive power the faster it flew."

The Great Aerodrome That Didn't

The War Department gave him $50,000 in 1898 and the Smithsonian added $20,000 — enormous money, and vastly more than the Wrights ever spent. The full-scale Great Aerodrome had wire-braced tandem wings, a Pénaud tail, a catapult launcher mounted on a Potomac houseboat, and a superb 50-horsepower engine designed largely by his assistant Charles Manly, who also volunteered to fly it. The Wright Flyer managed on twelve horsepower. What Langley's machine did not have was any means of controlling roll.

Both 1903 launches failed at the catapult. Manly, remarkably, walked away from both. The newspapers were merciless, and Langley abandoned the project. He discovered in June 1905 that a Smithsonian accountant, William Karr, had been embezzling from the institution, and refused his own salary in response. He had a stroke that November, went to Aiken, South Carolina, to recover, and died there of a second stroke on 27 February 1906, aged 71. He was buried at Forest Hills Cemetery in Boston.

The indignity outlived him. In 1914 Glenn Curtiss, embroiled in a patent fight with the Wrights, rebuilt and briefly flew the Great Aerodrome, and the Smithsonian used the stunt to claim Langley's machine had been "the first man-carrying aeroplane... capable of sustained free flight." The historian Fred Howard called that claim "a lie pure and simple."

Why Samuel Is Called a Genius

Two different cases can be made, and only one of them holds. The strong case is instrumental. The bolometer is a genuine work of experimental genius: a device that extended human perception by orders of magnitude, built from ordinary components by a man with no scientific degree, and sensitive enough that its readings still underpin climate science a century and a half later. Building an instrument that can measure what nobody has measured is among the rarest talents in science, and Langley had it. Add the intellectual nerve of taking heavier-than-air flight seriously when his entire profession considered it crankery, and of doing real aerodynamic measurement rather than tinkering.

The weak case is aeronautical, and it collapses under examination. Langley's machines flew when nobody was aboard and failed when somebody was, because he had solved lift and power while ignoring the problem the Wrights identified as central: control. He built no way to manage roll, launched from a catapult that gave a pilot no margin, and never learned to fly anything himself. With five times the money and four times the engine, he lost to two mechanics who had understood what the actual question was. It is worth noting that no contemporary in the surviving record reaches for the word "genius" about Langley; the Smithsonian instead reached for a falsehood about his priority, which is a poor substitute. He was a first-rate experimental physicist and a poor engineer of vehicles.

Legacy

The name is everywhere the aviation he failed at became routine: NASA's Langley Research Center, Langley Air Force Base, three ships named USS *Langley*, Mount Langley in the Sierra Nevada, the Smithsonian's Langley Gold Medal, and induction into the National Aviation Hall of Fame in 1963. The langley, a unit of solar irradiance, quietly commemorates the work he should be remembered for.

Achievements

• National Aviation Hall of Fame — 1963
• Affiliated with Harvard University, United States Naval Academy and Allegheny Observatory
• Educated at Boston English High School and Boston High School
• Worked as astronomer, aerospace engineer and astrophysicist