Edith Clarke: a pioneer in electrical engineering

Edith Clarke was born in 1883 in Howard County, Maryland. After earning a degree in mathematics and astronomy from Vassar College in 1908, she began her career as a mathematics and physics teacher. Her passion for the sciences led her to enroll in civil engineering at the University of Wisconsin-Madison, but due to career opportunities, she left her studies to take a job as a "computer" at AT&T in 1912. There, she worked with Dr. George Campbell, performing calculations related to long-distance electrical transmission.

In 1918, Clarke enrolled at the Massachusetts Institute of Technology (MIT), and a year later, she became the first woman to earn a master’s degree in electrical engineering from the institution. Despite this achievement, she faced difficulties in securing a job as an engineer. As a result, she joined General Electric (GE) as a supervisor of a team of "computers" in the turbine engineering department. During her time at GE, Clarke invented the "Clarke calculator" – a simple graphical device that allowed engineers to quickly solve equations related to electric current, voltage, and impedance in transmission lines. This device could solve equations involving hyperbolic functions ten times faster than previous methods. She filed a patent for this invention in 1921, which was granted in 1925.

In 1921, still unable to secure an engineering position, Clarke left GE to teach physics at Constantinople Women’s College in Turkey, seizing a rare opportunity to continue her scientific work in an academic setting. A year later, she returned to GE, this time as an electrical engineer in the Central Station Engineering department, becoming the first professionally employed female electrical engineer in the United States.

Clarke gained recognition for her mathematical skills. On February 8, 1926, she became the first woman to present a paper at the annual meeting of the American Institute of Electrical Engineers (AIEE), discussing the application of hyperbolic functions in calculating the maximum power that could be transmitted through a line without losing stability. In 1943, she published the influential textbook Circuit Analysis of A-C Power Systems, based on her lecture notes for engineers at GE. In 1947, she joined the electrical engineering faculty at the University of Texas at Austin, becoming the first female professor of electrical engineering in the country. She taught there for ten years until her retirement in 1957.

Clarke’s research on alternating current circuit analysis contributed to groundbreaking advancements in power transmission technology, allowing for more efficient and stable energy distribution. She is credited with revolutionizing electrical engineering, particularly in the field of power transmission system analysis. Her greatest breakthrough was developing mathematical methods and tools that allowed for more accurate and faster calculations related to power grid networks, significantly improving the design and operation of transmission lines.

So, what are some of the most significant contributions of this American researcher?

• Clarke Calculator – This graphical device she invented enabled faster equation-solving related to energy transmission, marking a major step forward in optimizing power grids.
• Pioneering use of hyperbolic functions in electrical circuit analysis – Her work allowed engineers to make more precise predictions about the performance and stability of power transmission lines.
• The book Circuit Analysis of A-C Power Systems – Considered a foundation of modern electrical engineering, it helped standardize calculation methods used in power network design.

Clarke’s work had a crucial impact on the development of large-scale power transmission systems. Thanks to her research, grid operators could design more efficient and stable transmission lines, which was vital for the advancement of global energy infrastructure. Beyond her technical contributions, Clarke also paved the way for women in engineering, demonstrating that competence and determination could overcome societal barriers.

Edith Clarke passed away on October 29, 1959, leaving behind a legacy as a pioneer who cleared the path for future generations of women in engineering. Her life and achievements serve as proof that determination, passion, and talent can break social barriers and open doors to success in male-dominated fields. On International Women’s Day, it is worth remembering figures like Edith Clarke, whose work and dedication contributed to the progress of science and technology, inspiring future generations of women to pursue careers in STEM.