Samuel Pierpont Langley

Infobox Scientist
name = Samuel Pierpont Langley
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caption = Samuel Pierpont Langley
birth_date = Birth date|1834|8|22
birth_place = Roxbury, Massachusetts
death_date = Death date and age|1906|2|27|1824|8|22
death_place = Aiken, South Carolina
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nationality = United States
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field = astronomy aviation
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known_for = solar physics
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prizes = Henry Draper Medal
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Samuel Pierpont Langley (August 22, 1834, Roxbury, Massachusetts – February 27, 1906, Aiken, South Carolina) was an American astronomer, physicist, inventor of the bolometer and pioneer of aviation. He graduated from Boston Latin School, was an assistant in the Harvard College Observatory, then became chair of mathematics at the United States Naval Academy. In 1867, he became the director of the Allegheny Observatory and a professor of astronomy at the Western University of Pennsylvania, now known as the University of Pittsburgh, a post he kept until 1891 even while he became the third Secretary of the Smithsonian Institution in 1887. Langley was the founder of the Smithsonian Astrophysical Observatory.

In 1886, Langley received the Henry Draper Medal from the National Academy of Sciences for his contributions to solar physics. His publication in 1890 of infrared observations at the Allegheny Observatory in Pittsburgh together with Frank Washington Very was used by Svante Arrhenius to make the first calculations on the greenhouse effect.

Aviation work

Langley attempted to make the first working piloted heavier-than-air aircraft. His models flew, but his two attempts at piloted flight were not successful. Langley began experimenting with rubber-band powered models and gliders in 1887. (According to one book, he was not able to reproduce Alphonse Pénaud's time aloft with rubber power but persisted anyway.) He built a rotating arm (functioning similar to a wind tunnel) and made larger flying models powered by miniature steam engines.
[
Potomac River, Oct. 7, 1903] His first success came on May 6, 1896 when his Number 5 unpiloted model flew half a mile after a catapult launch from a boat on the Potomac River. Though insufficiently controlled (a key requirement in the development of flight), aviation historians consider this to be the world's first sustained flight by a powered heavier-than-air craft. On November 11 that year his Number 6 model flew more than 5-thousand feet. These flights demonstrated that stability and sufficient lift could be achieved in such craft.{fact} In 1898, based on the success of his models, Langley was given a War Department grant of $50,000 and $20,000 from the Smithsonian Institution to develop a piloted airplane, which he called an "Aerodrome" (coined from Greek words roughly translated as "air runner"). Langley hired Charles M. Manly (1876-1927) as engineer and test pilot. When Langley received word from his friend Octave Chanute of the Wright brothers' success with their 1902 glider, he attempted to meet the Wrights, but they politely evaded his request.

While the full-scale Aerodrome was being designed and built, the internal combustion engine was contracted out to manufacturer Stephen Balzer (1864-1940). When he failed to produce an engine to the power and weight specifications, Manly finished the design. This engine had far more power than did the engine for the Wright brothers' first airplane—50 hp compared to 12 hp. The engine, mostly the technical work of men other than Langley, was probably the project's main contribution to aviation. [http://aerostories.free.fr/precurseurs/langley/mot_lang.jpg]

The piloted machine had wire-braced tandem wings (one behind the other). It had a Pénaud tail for pitch and yaw control but no roll control, depending instead on the dihedral angle of the wings, like the models, for maintaining roughly level flight. In contrast to the Wright brothers' design of a controllable airplane that could fly against a strong wind and land on solid ground, Langley sought safety by practicing in calm air over water, the Potomac River. This required a catapult for launching. The craft had no landing gear, the plan being to crash into the water after demonstrating flight. Langley gave up the project after two crashes on take-off on October 7 and December 8, 1903. In the first attempt, Langley said the wing clipped a wire, leading to the craft plunging into the Potomac River "like a handful of mortar" according to one reporter; the second attempt resulted in the craft breaking up as it left the catapult (Hallion, 2003; Nalty, 2003). Manly was recovered unhurt from the river. Newspapers made great sport of the failures.

The Aerodrome was heavily modified and flown a few hundred feet by Glenn Curtiss in 1914, as part of his attempt to fight the Wright brothers' patent, and as an effort by the Smithsonian to rescue Langley's aeronautical reputation. Nevertheless, courts upheld the patent. However, the Curtiss flights emboldened the Smithsonian to display the Aerodrome in its museum as "the first man-carrying aeroplane in the history of the world capable of sustained free flight". Fred Howard, extensively documenting the controversy, wrote: "It was a lie pure and simple, but it bore the imprimatur of the venerable Smithsonian and over the years would find its way into magazines, history books, and encyclopedias, much to the annoyance of those familiar with the facts." (Howard, 1987). The Smithsonian's action triggered a decades-long feud with the surviving Wright brother, Orville.

Langley had no effective way of addressing the Wright brothers' central innovation of controlling an airplane too big to be maneuvered by the weight of the pilot's body. So if the Aerodrome had flown stably, as the models did, Manly would have been in considerable danger when the machine descended, uncontrolled, for a landing—especially if it had wandered away from the river and over solid ground.

To his credit, Langley had to write reports and proposals during this project, while the Wright brothers were spending their own money.

A number of things related to aviation have been named in Langley's honor, including:

* Langley medal
* NASA Langley X-43A Hyper-X
* NASA Langley Research Center (NASA LaRC), Hampton, Virginia
* Langley Air Force Base
* Langley Memorial Aeronautical Laboratory
* Langley unit of solar radiation
* Mount Langley in the Sierra Nevada
* USS Langley (CV-1)
* USS Langley (CVL-27)

ee also

* Manley-Balzer engine

References

*"A Dream of Wings: Americans and the Airplane, 1875-1905," by Dr. Tom D. Crouch, W.W. Norton, 1981
*"Taking Flight: Inventing the Aerial Age, from Antiquity through the First World War", by Dr. Richard P. Hallion, Oxford University Press, 2003
*"Wilbur and Orville: A Biography of the Wright Brothers", by Fred Howard, Dover, 1987
*"A Heritage of Wings, An Illustrated History of Naval Aviation", by Richard C. Knott, Naval Institute Press, Annapolis, Maryland, 1997
*"Winged Shield, Winged Sword: 1907-1950: A History of the United States Air Force", by Bernard C. Nalty, University Press of the Pacific, 2003
*"Aviation, The Pioneer Years", edited by Ben Mackworth-Praed, Studio Editions, Ltd., London, 1990
* "To Conquer The Air—The Wright Brothers and the Great Race for Flight", by James Tobin, Free Press, Division of Simon & Shuster, 2003

External links

* [http://www.flyingmachines.org/lang.html Samuel Pierpont Langley, Flying Machines]
* [http://www.wright-house.com/wright-brothers/inventors/Langley.html Samuel Pierpont Langley, Invention of the Airplane]
* [http://www.centennialofflight.gov/index2.cfm Centennial of Flight]

Persondata
NAME=Langley, Samuel Pierpont
ALTERNATIVE NAMES=
SHORT DESCRIPTION=American physicist and pioneer of aviation
DATE OF BIRTH=August 22, 1834
PLACE OF BIRTH=Roxbury, Massachusetts
DATE OF DEATH=February 27, 1906
PLACE OF DEATH=Aiken, South Carolina