Edith Clarke (1883-1959) was a pioneer in electrical engineering who used math to improve our understanding of power transmission. She was the first professionally employed female electrical engineer and the first full-time female professor of electrical engineering in the country.
Edith Clarke was one of nine children born to lawyer John Ridgely Clarke and Susan Dorsey Owings in Howard County, Maryland. Orphaned at age 12, she was raised by an older sister and used her inheritance to study mathematics and astronomy at Vassar College, where she graduated in 1908.
After college, Clarke taught mathematics and physics at a private school in San Francisco and at Marshall College. She studied civil at the University of Wisconsin-Madison, but left to be become a “computer” at AT&T in 1912. While at AT&T, she studied electrical engineering at Columbia University by night.
In 1918, Clarke enrolled at MIT and in 1919 became the first woman to earn an M.S. in electrical engineering from MIT. Unable to find engineering, she worked for GE as supervisor of computers in the Turbine Engineering Department. During this time, she invented and later patented (in 1925) the Clarke calculator, an early graphing calculator which is used to solve equations involving electric current, voltage and impedance in power transmission lines.
In 1921, Clarke briefly left GE to teach physics in Turkey because she was not allowed to do electrical engineering work, plus, she was not earning the same salary and had a lower professional status than men doing the same work. She returned to GE in 1922 and was offered a salaried electrical engineering job in the Central Station Engineering Department – becoming the first professional female electrical engineer in the US. She retired from GE in 1945.
Clark was the first woman to deliver a paper at the American Institute of Electrical Engineers’ annual meeting, held in 1926. Two of her later papers won awards from the AIEE: the Best Regional Paper Prize in 1932 and the Best National Paper Prize in 1941.
Clarke helped design, develop, and install the turbines that still generate hydropower in the West Hoover Dam. In 1943, she wrote the textbook Circuit Analysis of A-C Power Systems, her adaption of the symmetrical components system—a mathematical means for engineers to study and solve problems of power system losses and the performance of electrical equipment. Clarke adopted this system to the three-phase components that is the basis of the US electrical grid.
In 1947, she joined Electrical Engineering Department at the University of Texas at Austin as the first female professor of electrical engineering in the country, where she taught for 10 years before retiring.
Edith Clarke was the first female engineer to achieve professional standing in Tau Beta Pi, the oldest engineering honor society and the second oldest collegiate honor society in the US. In 1948, she became the first female Fellow of the American Institute of Electrical Engineers.Clark was also the first woman accepted as a full voting member in the American Institute of Electrical Engineers. In 1954, she received the Society of Women Engineers Achievement Award “in recognition of her many original contributions to stability theory and circuit analysis.”
Clarke was selected for inclusion in Women of Achievement in Maryland History in 1998 and was also included in American National Biography and Notable American Women of the Modern Period. In 2015, Clarke was posthumously inducted into the National Inventors Hall of Fame.