While it’s no secret that electrical engineering is a male-dominated field (only 13% of engineers are women), female EEs have made invaluable contributions worth celebrating—especially during Women’s History Month.
One such engineer who warrants a spotlight in All About Circuits’ Historical Engineers series is Edith Clarke, the first woman in the United States to be employed as an electrical engineer. In addition to her groundbreaking research on electrical power system analysis, Clarke racked up a number of “firsts” for women in the field, leaving resounding effects today.
An Education Pointing to Transmission Line Analysis
While women have been earning degrees in engineering as early as the 1800s, none graduated with an advanced degree in electrical engineering before Edith Clarke.
Edith Clarke published 18 papers between 1923 and 1951. Image used courtesy of Wednesday’s Women
Orphaned at the age of 12, Clarke saved the inheritance from her parents to venture into academia when she was 18. After graduating from Vassar College in mathematics and astronomy in 1908 (women were barred from studying electrical engineering at Vassar at the time), Clarke began studying civil engineering at the University of Wisconsin.
Clarke took a left turn in her education, however, when she accepted a summer job as a “computer” to Dr. George Campbell, a research engineer at AT&T. It was at this position that Clarke developed a keen interest in Campbell’s work, applying mathematical methods to solve issues related to long-distance electrical transmission. To learn more, Clarke concurrently began taking electrical engineering classes by night at the University of Columbia.
Transmission lines during Clarke’s time. Image from the Edison Tech Center
By 1918, Clarke was ready to take her next educational leap: applying to MIT’s electrical engineering program. Not only was Clarke accepted but she also graduated with her M.S. in electrical engineering the following year—the first woman in the program to accomplish such a feat. Spinning out of her studies with Campbell, Clarke’s thesis focused on the behavior of artificial transmission lines as frequency was continuously increased.
The First Female Electrical Engineer
Early in her professional career, Clarke faced significant setbacks because of her sex. Unable to find work as an electrical engineer, Clarke worked as a computer once more after graduating from MIT—this time for General Electric. It was there that Clarke filed her first patent on a “graphical calculator” (an early graphing calculator) in 1921. Clarke’s device solved basic equations involving the voltage, impedance, and current in power transmission lines ten times faster than other methods of the day.
Patent of the “Clarke Calculator,” which was granted in 1925. Image used courtesy of Autodesk
Clarke temporarily took a leave of absence from GE to teach physics at the Constantinople Women’s College in Turkey, only to return a year later and receive a salaried position as an electrical engineer at GE. This promotion made her the first female electrical engineer in the United States.
In 1926, Clarke was also noted as the first woman to present at the American Institute of Electrical Engineers (an early iteration of the Institute of Electrical and Electronic Engineers or “IEEE”). There, she elucidated a groundbreaking method of modeling large-scale power systems using symmetrical components from small-scale systems.
In the 1920s, transmission lines were lengthening, which in turn increased loads and upped the chances for system instability. Clarke’s mathematical modeling significantly simplified the process of analyzing these larger systems.
Clarke’s Lasting Impact: From the U.S. Power Grid to the Hoover Dam
Clarke was a prolific writer on power distribution and synchronous machines and authored a foundational power engineering textbook during her lifetime: Circuit Analysis of A-C Power Systems. Some of the principles in this text involving three-phase components form the basis of the United States electrical grid today.
Title page of Clarke’s textbook. Image used courtesy of the Internet Archive
Additionally, Clarke played a significant role in the construction of the Hoover Dam, where she provided her expertise to develop turbines that generate hydropower.
After a 26-year career at GE, Clarke headed to the University of Texas, Austin, where she became the first woman to teach electrical engineering until her retirement in 1957. It was around this time that Clark was elected to be a fellow at the American Institute of Electrical Engineers—another first for women.
In a biographical report on Edith Clarke, Dr. James E. Brittain emphasizes how Clarke’s work has had a lasting impact on our current understanding of electrical power systems.
“She translated what many engineers found to be esoteric mathematical methods into graphs or simpler forms during a time when power systems were becoming more complex and when the initial efforts were being made to develop electromechanical aids to problem-solving,” he explains.
“As a woman who worked in an environment traditionally dominated by men, she demonstrated effectively that women could perform at least as well as men if given the opportunity.”