Women have been involved in computing since the 18th century. Before the advent of machines that could perform computations, people who "performed mathematical calculations were known as computers." Women developed scientific computations, including Nicole-Reine Lepaute's prediction of the return of Halley's Comet, and Maria Mitchell's computation of the motion of Venus. As technology and practices evolved, the role of women in computation and programming changed, and the recorded history of the field has subsequently downplayed their achievements.
The first algorithm intended to be executed by a mechanical computer was designed by pioneering Ada Lovelace, while Grace Hopper was the first person to design a compiler for a programming language. Throughout the 19th and early 20th century, and up to World War II, computing was predominantly done by women; significant examples include the Harvard Computers, women codebreakers at Bletchley Park and engineers at NASA.
Starting in the 1960s but accelerating in the late 20th century computing professions began to be more lucrative and high-status, leading to women becoming increasingly marginalized in the field. In the 21st century, women have held leadership roles in multiple tech companies, such as Meg Cushing Whitman, president and chief executive officer of Hewlett Packard Enterprise, and Marissa Mayer, president and CEO of Yahoo! and key spokesperson at Google.
History
19th century
Maria Mitchell was one of the first computers for the U.S. Nautical Almanac Office. Her primary job was to compute the motion of Venus and other planets, and to create navigation tables for naval use. Later, Mitchell became the first female astronomy professor at Vassar College.
Ada Lovelace was the first person to publish an algorithm intended to be executed by the first modern computer, the Analytical Engine created by Charles Babbage. As a result, she is often regarded as the first computer programmer. Lovelace was introduced to Babbage's difference engine when she was 17, and in 1840, she wrote to Babbage and asked if she could become involved with his first machine. By this time, Babbage had moved on to his idea for the Analytical Engine. A paper describing the Analytical Engine, Notions sur la machine analytique, published by L.F. Menabrea, came to the attention of Lovelace, who not only translated it into English, but corrected mistakes made by Menabrea. Babbage suggested that she expand the translation of the paper with her own ideas, which, signed only with her initials, AAL, "synthesized the vast scope of Babbage's vision." Lovelace imagined the kind of impact the Analytical Engine might have on society. She drew up explanations of how the engine could handle inputs, outputs, processing and data storage. She also created several proofs to show how the engine would handle calculations of Bernoulli Numbers on its own. The proofs are considered the first examples of a computer program. Lovelace downplayed her role in her work during her life, for example, in signing her contributions with AAL so as not be "accused of bragging."
After the Civil War in the United States, more women were hired as human computers. Many were war widows looking for ways to support themselves. Others were hired when the government opened positions to women because of a shortage of men to fill the roles.
Anna Winlock asked to become a computer for the Harvard Observatory in 1875 and was hired to work for 25 cents an hour. By 1880, Edward Charles Pickering had hired several women to work for him at Harvard because he knew that women could do the job as well as men and he could ask them to volunteer or work for less pay. The women, described as "Pickering's harem" and also as the Harvard Computers, performed clerical work that the male employees and scholars considered to be tedious at a fraction of the cost of hiring a man. The women working for Pickering cataloged around ten thousand stars, discovered the Horsehead Nebula and developed the system to describe stars. One of the "computers," Annie Jump Cannon, could classify stars at a rate of three stars per minute. The work for Pickering became so popular that women volunteered to work for free even when the computers were being paid. Even though they performed an important role, the Harvard Computers were paid less than factory workers.
By the 1890s, women computers were college graduates looking for jobs where they could use their training in a useful way. Florence Tebb Weldon, was part of this group and provided computations relating to biology and evidence for Darwin's theory of evolution, working with her husband, W.F. Raphael Weldon. Another human computer involved in biology was Alice Lee, who worked with Karl Pearson. Pearson also hired two sisters to work as part-time computers at his Biometrics Lab, Beatrice and Frances Cave-Browne-Cave.
1910s During World War I, Karl Pearson and his Biometrics Lab helped produce ballistics calculations for the British Ministry of Munitions. Beatrice Cave-Browne-Cave helped calculate trajectories for bomb shells. In 1916, Cave-Browne-Cave left Pearson's employ and started working full-time for the Ministry. In the United States, women computers were hired to calculate ballistics in 1918, working in a building on the Washington Mall. One of the women, Elizabeth Webb Wilson, worked as the chief computer. After the war, women who worked as ballistics computers for the U.S. government had trouble finding jobs in computing and Wilson eventually taught high school math.
1920s
In the early 1920s, Iowa State College professor George Snedecor worked to improve the school's science and engineering departments, experimenting with new punch-card machines and calculators. Snedecor also worked with human calculators, most of whom were women, including Mary Clem. Clem coined the term "zero check" to help identify errors in calculations. The computing lab, run by Clem, became one of the most powerful computing facilities of the time.
Women computers also worked at the American Telephone and Telegraph company. These human computers worked with electrical engineers to help figure out how to boost signals with vacuum tube amplifiers. One of the computers, Clara Froelich, was eventually moved along with the other computers to their own division where they worked with a mathematician, Thornton Fry, to create new computational methods. Froelich studied IBM tabulating equipment and desk calculating machines to see if she could adapt the machine method to calculations.
Edith Clarke was the first woman to earn a degree in electrical engineering and who worked as the first professionally employed electrical engineer in the United States. She was hired by General Electric as a full engineer in 1923. Clarke also filed a patent in 1921 for a graphical calculator to be used in solving problems in power lines. It was granted in 1925.
1930s The National Advisory Committee for Aeronautics (NACA), which ultimately became NASA, hired a group of five women in 1935 to work as a computer pool. The women worked on the data coming from wind tunnel and flight tests.
The Works Progress Administration hired women as human calculators in order to support engineers during World War II. This was largely seen as menial labor, and much of the work was focused on calculations and less on problem solving.
Barbara Canright was recruited for California’s Jet Propulsion Laboratory in 1939 as a human calculator, largely working with engineers in order to determine thrust-to-weight ratios and other various aeronautics calculations.
1940s
"Tedious" computing and calculating was seen as "women's work" through the 1940s, resulting in the term "kilogirl", coined by a member of the Applied Mathematics Panel in the early 1940s. A "kilogirl" of energy was "equivalent to roughly a thousand hours of computing labor." While women's contributions to the United States war effort during World War II were championed in the media, their roles and the nature of the work they did was minimized. This included minimizing the complexity, skill and knowledge needed to work on computers or work as human computers. During WWII, women did most of the ballistics computing, seen by male engineers as being below their level of expertise. Black women computers worked as hard (or more often, even harder) as their white counterparts, but in segregated situations. By 1943, almost all people employed as computers were women; one report said "programming requires lots of patience, persistence and a capacity for detail and those are traits that many girls have". Technology historian Mar Hicks wrote in Programmed Inequality that "women were the largest trained technical workforce of the computing industry during the second world war and through to the mid-sixties."
NACA expanded its pool of women human computers in the 1940s. NACA recognized in 1942 that "the engineers admit themselves that the girl computers do the work more rapidly and accurately than they could." In 1943, two groups, segregated by race, worked on the east and west side of Langley Air Force Base. The black women were the West Area Computers. Unlike their white counterparts, the black women were asked by NACA to re-do college courses they had already passed and many never received promotions.
Women were also working on ballistic missile calculations. In 1948, women such as Barbara Paulson were working on the WAC Corporal, determining trajectories the missiles would take after launch.
Women worked with cryptography, including on Bombe machines. Joyce Aylard operated the Bombe machine, testing different methods to break the Enigma code. Joan Clarke was a cryptographer who worked with her friend, Alan Turing, on the Enigma machine at Bletchley Park. When she was promoted to a higher salary grade, there were no positions in the civil service for a "senior female cryptanalyst," and she was listed as a linguist instead. Clarke developed a method for increasing the speed of double-encrypted messages, but unlike many of her male colleagues, her decryption technique was not named after her. Other cryptographers at Bletchley included Margaret Rock, Mavis Lever (later Batey), Ruth Briggs and Kerry Howard. In 1941, Batey's work enabled the Allies to break the Italians' naval code before the Battle of Cape Matapan. In the United States, several faster Bombe machines were created. Women, like Louise Pearsall, were recruited from the WAVES to work on code breaking and operate the American Bombe machines.
Hedy Lamarr and co-inventor, George Antheil, worked on a frequency hopping method to help the Navy control torpedoes remotely. The Navy passed on their idea, but Lamarr and Antheil received a patent for the work on August 11, 1942. This technique would later be used again, first in the 1950s at Sylvania Electronic Systems Division and ultimately in technology such as Bluetooth and Wi-Fi.