Female Computers of the 18th Century

200 years ago, a computer was a professional making a living by computing figures for charts and tables.
Men were predominant in this job, but a small number of women joined them and made remarkable achievements. Read more about three extraordinary careers in this post.

Working as a computer in the 18th century

In the 17th century, a „computer” usually was a personal assistant to an astronomers, helping out in calculating the positions of planets. Yet, this usually was a temporary job, related to a specific task to be done for an individual. Computing became more organized in in 1757, when Alexis Claude Clairaut (1713–1765) started a project to calculate the time of the return of Halley’s Comet. For this, the computations were done by a team, and one of the team members was a woman (we come back to her in a minute). The team’s method was to divide large calculations into independent pieces, assembling the results from each piece into a final product, and then to check for errors. The method became the basis for professional computing in the 18th and 19th century.

From the late 1760s, computers often worked to create celestial tables for almanacs. The industrial revolution furthered the need for accurate tables for navigation and engineering. However, it was a vanishingly small number of women who made a living from computing. You will get to know two of them in this article.

Into the future of computing

Women were increasingly involved in computing only from around 1865, when private companies began to hire female staff for computing. Their job was to undertake long calculations according to fixed rules. Creative thinking wasn’t a necessary qualification.
Interestingly, computing was an early form of home office: Educated middle class women working as computers would receive and send back packets of calculations by post, as society thought it improper for them to engage in the profession or go out to work.

Women in computing: three careers

Nicole-Reine Lepaute (1723 – 1788) – rising to fame in a men’s world

Portrait of Nicole-Reine Lepaute

The daughter of a valet of a member of the French Royal family was precocious and intelligent, and mostly self-taught. She married the royal clockmaker Jean-Andre Lepaute, and helped him constructing a clock with an astronomical function. Besides, they both worked on a book titled Traite d’horlogerie” (Treatise of Clockmaking), published in 1755 under her husband’s name only.

„Madame Lepaute computed for this book a table of numbers of oscillations for pendulums of different lengths, or the lengths for each given number of vibrations, from that of 18 lignes, that does 18000 vibrations per hour, up to that of 3000 leagues.”
(Jérôme Lalande, adjunct astronomer to the French Academy of Sciences, on Nicole’s achievements for „Traite d’horlogerie”)

Working for project „Halley’s Comet”

Nicole joined Alexis Claude Clairaut and Jérôme Lalande to calculate the return of Halley’s Comet. It was a had hard task, taking 6 months to finish. In November 1758, the team presented their conclusion: The comet would arrive on 13 April 1759 (Close enough for fame. The comet arrived on 13 March 1759, but still the team got the full credit). Clairault did not recognize Nicole’s work in the project, but Lalande did. He considered Nicole the „most distinguished female French astronomer ever.”

„For six month we made calculations from dawn to dusk, sometimes even during the meals (…) The help given by Mme Lepaute was such that without her I would not have been able to complete such a colossal enterprise (…).”
(Jérôme Lalande, adjunct astronomer to the French Academy of Sciences, on Nicole’s achievements for calculating the return of Halley’s Comet)

Nicole and Lalande continued to collaborate for fifteen years on the Academy of Science’s annual guides for astronomers and navigators. In 1761, Nicole became an honorary member of the distinguished Scientific Academy of Béziers. One year later, she calculated the exact time of a solar eclipse that occurred on 1 April 1764. Here article about it was published in Connaissance des Temps (Knowledge of the times). She also calculated the ephemerides of the Sun, the Moon and the planets for the years 1774–1784.

Map of visibility of the total solar eclipse in 1764 by Nicole Reine Lepaute (French National Library)

Mary Edwards (ca. 1750 – 1815) – an extraordinary career in computing

In the 18th century, it was unheard of for a woman to occupy an academic government-funded position. Yet, Mary Edwards did. She worked as a computer from 1773 – 1815 from her home at 4 Brand Lane, Ludlow.

How did Mary’s career come about?

Mary was married to Reverend John Edward, a hobby-astronomer. He had been given a job as computer by the Astronomer Royal, Nevil Maskelyne. His task was to compile charts for the British Nautical Almana (edited and published since 1767 by Maskelyne). The charts helped sailors to find their way safely at sea. As Britain was a leading seafaring nation, the publication was funded by the government through the Board of Longitude. John earned six pounds and five shillings for each month’s worth of completed tables. He worked from his home in Ludlow.

But actually, it was Mary who was doing nearly all her husband’s computer work since he had been first hired. We don’t know how Mary acquired the mathematical skills needed for the job as a computer. But we know that she did the job very well. When John died in 1784, Mary asked Maskelyne for permission to continue her work. He agreed, and even created an account with the name ‘Mary Edwards’. She received the same pay as her husband, and now officially was as one of 35 computers working for the Almanac.

The Nautical Almanac and Astronomical Ephemeris for the Year 1778, printed in 1777. Mary Edwards contributed to this work.

Extraordinary achievements

Mary was regularly trusted with computing a full year’s worth of tables. This means that she did half of the almanac’s computing on her own. In 1809, she was given the more prestigious position of Nautical Almanac comparer. This also meant a pay-rise to £250 per almanac. This was a respectable sum: Mary made about £24 more than a newly posted captain in the Royal Navy earned in a year.

Trouble with the new boss

Trouble arose when Maskelyne died in 1811. The new editor of the Nautical Almanac, John Pond, reduced Mary’s work, which meant she earned less. Mary didn’t accept this quietly. She sent a petition to the Board and to Parliament. As a result, the Board acknowledged that she had been a good and faithful worker for many years. She was granted to compute 8 months of the Nautical Almanac while being paid for almost 12 months’ work. The Board did not reinstate her to the position of Nautical Almanac comparer.

Mary worked for the Almanac until her death in 1815.

Eliza Edwards (1779-1846) – A career ending by gender-based discrimination

When the computers of the Nautical Almanac were reorganised as a branch of the Civil Service, Eliza’s career ended.

Mary Edwards encouraged her daughters to work as a computer. One of them, Eliza, joined in the work for the Nautical Almanac in 1809. She continued her mother’s work after her death in 1815, and computed for the Nautical Almanac until 1832.

Eliza had to drop out of the job when the computing for the Almanac was centralised as a branch of civil service at the new HM Nautical Almanac Office. In those days it was nearly impossible for a woman to be employed in Civil Service.

Computing as a profession: the beginning of the end

You might expect me to mention Ada Lovelace (1815 –1852) in this article – and I do.

The daughter of Lord Byron became famous for publishing in 1843 an algorithm for the first modern computer, the so called Analytical Engine” (being an unfinished invention by Charles Babbage). Ada is therefore often regarded as the first computer programmer. She certainly was a brilliant mathematician, but she didn’t work as a computer.

The Analytical Engine that Ada helped to invent aimed to automate the production of numerical tables, reducing human errors. Actually, Babbage thought the machine should produce accurate tables of star positions to supplement the Nautical Almanac (the one Mary Edwards worked for. Babbage himself had applied for the post of computer for the Royal Observatory in 1814, but later withdraw his application). Charles Babbage and Ada Lovelace didn’t succeed in their time. The modern computer, however replaced the professional human computer” in the end.

Model of the Analytical Engine by Charles Babbage. The Analytical Engine is considered to be first modern computer.

If you are interested in machines helping with calculating, here are some inventions form the late 18th century for you enjoy here:

Mechanical Calculator by Jakon Auch, 1790, on display at
Mathematisch-Physikalischer Salon, Zwinger, 01067 Dresden / Germany
Mechanical calculator, 1790 by Jakob Auch, used for calculating money
Mechanical calculator, 1796 by Jakob Auch

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Article by Anna M. Thane, author of the novel
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