William D. Coolidge

Is your surname Coolidge?

Research the Coolidge family

Share your family tree and photos with the people you know and love

  • Build your family tree online
  • Share photos and videos
  • Smart Matching™ technology
  • Free!

Dr. William David Coolidge

Birthplace: Hudson, MA, United States
Death: February 03, 1975 (101)
Place of Burial: Schenectady, NY, United States
Immediate Family:

Son of Albert Edward Coolidge and Mary Alice Coolidge
Husband of Dorothy F. Coolidge and Ethel Wescott Coolidge

Occupation: inventor and developer of the tungsten filament
Managed by: Private User
Last Updated:

About William D. Coolidge

Retired General Electric researcher who revolutionized the electrical industry with his development of ductile tungsten in 1908. Coolidge's pliable tungsten filaments made light bulbs longer-lasting and less expensive, and ductile tungsten was at the heart of the Coolidge tube, the prototype of modern X-ray tubes

Dr. Coolidge (1873-1975) graduated MIT in electrical engineering in 1896 and earned his Ph.D. at the University of Leipzig in 1899.After serving in several academic positions at MIT, he joined the General Electric Research Laboratory in 1905, and remained in the employ of GE for rest of his career, becoming Director of the Research Laboratory in 1932 and GE Vice President and Director of Research in 1940. A General Electric biography provides a brief summary of his career.

In 1928 Dr. Coolidge was awarded the Edison Medal of the American Institure of Electrical Engineers "for his contributions to incadescent electric lighting and the x-ray arts." Today's incadescent light bulbs use filaments made of ductile tungsten using processes developed by Dr. Coolidge (Patent 1,082,933 granted in 1913). The Coolidge tube (Patent 1,203,495 granted 1916), used for medical and industrial x-ray sciences, was invented and developed in the GE Laboratory, with Dr. Coolidge receiving over three dozens related patents.

In 1975 at age 100, William David Coolidge was elected to the National Inventor's Hall of Fame.

In 1917 it became evident that the involvement in World War I by the U.S. was unavoidable. The GE Research Laboratory and Dr. Whitney became increasingly concerned with the possible role they could play in such an event, and development of a submarine detection system was an obvious challenge. Allied shipping was being sunk at a far greater rate than it could be replaced, and some solution of this problem was urgently needed. The depth bomb was an effective weapon if the submarine could be located, which was the key problem.

Prior to the entry of the U.S. into the war, the GE Research Laboratory became involved in war work through the Naval Consulting Board, on which Dr. Whitney served. A joint attack on the problem of submarine detection was planned involving GE, the Submarine Signalling Company, and Western Electric. An experimental station was set up on the Mohawk River, near where the GE Research and Development Center was located years later. Coolidge soon found that sealed rubber binaural listening tubes provided excellent range of about two miles with an azimuth sensitivity of about five degrees. This device went into service on U.S. and British vessels as the "C" Tube—for Coolidge. A later version, the "K" tube, developed a range of ten miles with an azimuth sensitivity of ten degrees. These devices permitted submarine chasers to clear the Mediterranean of submarines in the spring and summer of 1918 and were an important factor in the final outcome of the war. The Coolidge tube was adapted to a field X-ray unit for use in World War I, and it became a major medical tool in field hospitals, where many practitioners became acquainted with it for the first time.

In the period following World War I, the Research Laboratory under Whitney grew in stature and influence, both within the company and in the scientific community. Langmnir's work on electron emission and surface chemistry found many important applications, including radio broadcasting and reception. Albert Hull was one of three scientists (with Debye and Scherrer) to develop X-ray diffraction in crystalline materials. His studies of gas-filled electron tubes helped open up the field of industrial electronics. Coolidge continued to expand the usefulness of X-rays by the development of million-volt, high-power generators for medical therapeutic work and multiple industrial uses. The year 1932 was an important year for the laboratory, for Coolidge became director upon the retirement of Whitney, and in the same year Langmuir became the first American industrial scientist to win the Nobel Prize.

By the time World War II broke out, the appreciation of the role of science and technology in the national defense establishment was well developed, and through the leadership of Dr. Vannevar Bush, a massive national research and development program was mounted to aid the war effort. The Office of Scientific Research and Development identified the areas of opportunity; organized the effort in university, industrial, and government laboratories; and provided the necessary financial backing. Coolidge became involved in the atomic bomb investigation from the beginning as a member of President Roosevelt's Advisory Committee on Uranium. In 1940 Dr. A. O. Nier of the University of Minnesota and Drs. K. H. Kingdon and H. C. Pollock of the GE Research Laboratory isolated U235 for the first time, and showed that it was the fissionable isotope. This author became a member of Division 13 of the NDRC (microwave radar) and chairman of Division 15 (radio and radar countermeasures), and both subjects became active areas for the participation of the GE Research Laboratory in the war effort.

Coolidge had planned to retire about the time World War II began in Europe, but because of the pressure of wartime work he agreed to stay on beyond his normal retirement. At the war's conclusion he resumed his plans for retirement, and he proposed that I succeed to his position, which I did on January 1, 1945. In retirement, Coolidge retained an active interest in X-ray research. He continued to receive recognition in the form of awards and medals for the impressive work of his career, even through his one-hundreth birthday, and he continued the photography hobby that dated from his boyhood in Massachusetts.

The "Coolidge tube"

Although some of the milestones in Will Coolidge's remarkable career have been suggested above, this biography would be incomplete without words of appreciation for his personal qualities, which were equally impressive. Kindness and thoughtfulness in dealing with friends and associates were attributes that were deeply imbedded in his nature. I doubt if anyone ever heard him raise his voice in anger. His modesty was almost embarrassing, and he always viewed the accomplishments of his associates more generously than they themselves. He was greatly beloved by everyone who was privileged to be associated with him, and in the world of science, including medical science, he was regarded with deep reverence, as evidenced by the unprecedented award from the University of Zurich of a Doctorate of Medicine.

Posted by Walter G. Ashworth, cousin


William David Coolidge (October 23, 1873 – February 3, 1975) was an American physicist, who made major contributions to X-ray machines. He was the director of the General Electric Research Laboratory and a vice-president of the corporation. He was also famous for the invention of "ductile tungsten", which is important for the incandescent light bulb.

Early years

Coolidge was born on a farm near Hudson, Massachusetts. He studied electrical engineering from 1891 until 1896 at the Massachusetts Institute of Technology (MIT). After a year as a laboratory assistant, he went to Germany for further study and received his doctorate from the University of Leipzig. 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's new research laboratory in 1905, where he conducted experiments that led to the use of tungsten as filaments in light bulbs. 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 for use in X-ray machines that allowed for more intense visualization of deep-seated anatomy and tumors. The Coolidge tube, which also utilized a tungsten filament, was a major development in the then-nascent medical specialty of radiology, and its basic design is still in use. He filed for patent in 1913 and finally it was granted as US Patent 1,203,495 in 1916.


The American Academy of Arts and Sciences awarded Coolidge the Rumford Prize in 1914. Coolidge was awarded the American Institute of Electrical Engineers Edison Medal 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 in 1926 and the Louis E. Levy Medal in 1927. Coolidge was awarded the Faraday Medal in 1939. He was awarded the Franklin Medal in 1944. In 1975 he was elected to the National Inventors Hall of Fame, shortly before his death at age 101 in Schenectady, 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.

view all

William D. Coolidge's Timeline

October 23, 1873
Hudson, MA, United States
February 3, 1975
Age 101
Vale Cemetery, Schenectady, NY, United States