William David Coolidge (; October 23, 1873 – February 3, 1975) was an American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

and

engineer Engineers, as practitioners of engineering, are professionals who Invention, invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considerin ...

, who made major contributions to

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

machines. He was the director of the

General Electric Research Laboratory General Electric Research Laboratory was the first industrial research facility in the United States. Established in 1900, the lab was home to the early technological breakthroughs of General Electric and created a research and development environm ...

and a vice-president of the corporation. He was also famous for the development of "ductile

tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isol ...

", which is important for the incandescent

light bulb An electric light, lamp, or light bulb is an electrical component that produces light. It is the most common form of artificial lighting. Lamps usually have a base made of ceramic, metal, glass, or plastic, which secures the lamp in the soc ...

Early years

Coolidge was born on a farm near Hudson,

Massachusetts Massachusetts (Massachusett: ''Muhsachuweesut Massachusett_writing_systems.html" ;"title="nowiki/> məhswatʃəwiːsət.html" ;"title="Massachusett writing systems">məhswatʃəwiːsət">Massachusett writing systems">məhswatʃəwiːsət'' En ...

. He studied

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

from 1891 until 1896 at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of th ...

(MIT). After a year as a laboratory assistant, he went to Germany for further study and received his doctorate from the

University of Leipzig Leipzig University (german: Universität Leipzig), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December ...

. From 1899 to 1905 he was a research assistant to Arthur A. Noyes of the Chemistry Department at MIT.

Ductile tungsten

Coolidge went to work as a researcher at

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable ene ...

's new research laboratory in 1905, where he conducted experiments that led to the use of

filament The word filament, which is descended from Latin ''filum'' meaning " thread", is used in English for a variety of thread-like structures, including: Astronomy * Galaxy filament, the largest known cosmic structures in the universe * Solar filament ...

s in

s. He developed 'ductile tungsten', which could be more easily drawn into filaments, by purifying tungsten oxide. Starting in 1911, General Electric marketed lamps using the new metal and they soon became an important source of income for GE. He applied for and received a patent (US#1,082,933) for this 'invention' in 1913. However, in 1928 a US court ruled that his 1913 patent was not valid as an invention.

Improved X-ray tube

In 1913 he invented the Coolidge tube, an X-ray tube with an improved

cathode A cathode is the electrode from which a conventional current leaves a polarized electrical device. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. A conventional current describes the direction in whi ...

for use in

machines that allowed for more intense visualization of deep-seated anatomy and tumors. The Coolidge tube, which also utilized a

, was a major development in the then-nascent medical specialty of

radiology Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiat ...

(US patent filed in 1913 and granted as US Patent 1,203,495 in 1916). Its basic design is still in use. He also invented the first rotating anode X-ray tube.

Awards

The

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

awarded Coolidge the Rumford Prize in 1914. Coolidge was awarded the

American Institute of Electrical Engineers The American Institute of Electrical Engineers (AIEE) was a United States-based organization of electrical engineers that existed from 1884 through 1962. On January 1, 1963, it merged with the Institute of Radio Engineers (IRE) to form the Insti ...

Edison Medal The IEEE Edison Medal is presented by the Institute of Electrical and Electronics Engineers (IEEE) "for a career of meritorious achievement in electrical science, electrical engineering, or the electrical arts." It is the oldest medal in this fi ...

in 1927 ''For his contributions to the incandescent electric lighting and the X-rays art''. He rejected this prestigious award in 1926 on the basis that his ductile tungsten patent (1913) was ruled by court as invalid. He was awarded the

Howard N. Potts Medal The Howard N. Potts Medal was one of The Franklin Institute Awards for science and engineering award presented by the Franklin Institute of Philadelphia, Pennsylvania. It is named for Howard N. Potts. The first Howard N. Potts Medal was awarded in ...

in 1926 and the Louis E. Levy Medal in 1927. Coolidge was awarded the

Faraday Medal The Faraday Medal is a top international medal awarded by the UK Institution of Engineering and Technology (IET) (previously called the Institution of Electrical Engineers (IEE)). It is part of the IET Achievement Medals collection of awards. ...

in 1939. He was awarded the

Franklin Medal The Franklin Medal was a science award presented from 1915 until 1997 by the Franklin Institute located in Philadelphia, Pennsylvania, U.S. It was founded in 1914 by Samuel Insull. The Franklin Medal was the most prestigious of the various awar ...

in 1944.James E. Brittain ''History William D. Coolidge and Ductile Tungsten'' in ''IEEE Industry Applications Magazine'', Sept/Oct 2004, page 10 The city of Remscheid awarded him with the Röntgen Medal for his invention of the hot cathode X-ray tube in 1963. In 1975 he was elected to the

National Inventors Hall of Fame The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization, founded in 1973, which recognizes individual engineers and inventors who hold a U.S. patent of significant technology. Besides the Hall of Fame, it also oper ...

, shortly before his death at age 101 in

Schenectady Schenectady () is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2020 census, the city's population of 67,047 made it the state's ninth-largest city by population. The city is in eastern New Y ...

, New York.

Later career

Coolidge became director of the GE research laboratory in 1932, and a vice-president of General Electric in 1940, until his retirement in 1944. He continued to consult for GE after retirement.

Patents

* Coolidge, , "Tungsten and method of making the same for use as filaments of incandescent electric lamps and for other purposes." * Coolidge, , Coolidge tube * Coolidge, , "''

X-ray tube An X-ray tube is a vacuum tube that converts electrical input power into X-rays. The availability of this controllable source of X-rays created the field of radiography, the imaging of partly opaque objects with penetrating radiation. In contrast ...

''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''

Stereoscopic Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word ''stereoscopy'' derives . Any stereoscopic image is ...

x-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray tube shield * Coolidge, , "''X-ray device''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus and method''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray apparatus''" * Coolidge, , "''X-ray device''" * Coolidge, , "''X-ray

anode An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemonic is ...

''" * Coolidge, , "''X-ray tube''" * Coolidge, , "''X-ray tube''" * Coolidge, , "''X-ray device''" * Coolidge, , "''X-ray device''"

Notes

References

** *

External links

The Cathode Ray Tube siteWilliam Coolidge's Case File at The Franklin Institute
with info about his 1926 Franklin Award for the x-ray tube
IEEE History Center biographyNational Academy of Sciences Biographical MemoirAndrea Sella's Classic Kit: Coolidge's X-ray Tube
*John Anderson Miller, ''Yankee scientist: William David Coolidge'', Mohawk Development Service, 1963 {{DEFAULTSORT:Coolidge, William American physicists Members of the United States National Academy of Sciences IEEE Edison Medal recipients MIT School of Engineering alumni 20th-century American inventors American centenarians Men centenarians People from Hudson, Massachusetts 1873 births 1975 deaths Howard N. Potts Medal recipients