A universal historian
Name: Agnes Mary Clerke
Claim to fame: Historian of astronomy who did much to popularise science
Following in the footsteps of Caroline Herschel (1750-1848) and Mary Somerville (1780-1872), Agnes Mary Clerke (1842-1907) was a woman with a passion for the stars. Her books and numerous articles introduced astronomy to a wide public, capturing their interest whilst also winning her the respect of the profession.
The young stargazer
From an early age, Agnes Mary Clerke delighted in mathematics and astronomy. Born in Skibbereen, Ireland on 10 February 1842, Clerke grew up in a family devoted to scientific study. Her father, John Willis Clerke, was a keen amateur scientist and he encouraged all of his children – Agnes, Ellen and Aubrey St John – to take an active interest. The Clerkes conducted chemistry experiments in a makeshift laboratory and kept a telescope mounted in the garden.
All of the Clerke children were educated at home, studying Latin, Greek, mathematics and astronomy. It was the last of these that most attracted Agnes and she began writing a history of the subject at the tender age of 15.
From 1867, Agnes, Ellen and their mother began to spend their winters in Florence, Italy. The sisters, who shared an interest in astronomy, moved there in 1873 and stayed for the next four years. Agnes spent much of her time in the city’s impressive libraries, indulging her passion for scientific knowledge.
She published her first book, A popular history of astronomy during the nineteenth century, in 1885. In essence, it was a general book aimed at a wide public, but it brought Agnes to the attention of the astronomical community and made her famous. The work was so thorough that it is still the standard text on the subject today.
In 1888, Agnes spent three months in South Africa as a guest of the Scottish astronomer David Gill and his wife. At the Cape Observatory, she was able, perhaps for the first time, to see the spectra (range of light colours) of stars, which she found fascinating and would subsequently discuss in her books.
A galaxy of information
Clerke continued to write about astronomy until her death on 20 January 1907. Her later books included The system of the stars (1890), which dealt with the make-up of the visible universe; Problems in astrophysics (1903), which detailed the current status of work in that field; and Modern cosmogonies (1905), an account of theories on the evolution of the universe.
In addition to her books and periodical articles, Agnes contributed the main article on the history of astronomy to the 11th edition of the Encyclopaedia Britannica, along with biographies of 30 astronomers.
Agnes Mary Clerke has a place in scientific history thanks to her impressive books on astronomy and astrophysics. In these works, she presented and considered the relevant facts in an articulate manner, discussing problems and highlighting future research possibilities for observational astronomers to tackle. Clerke was a pioneer in popularising astronomy and she foresaw the important role that astronomy would play in the 20th century. She was particularly interested in the emerging technique of spectroscopy, which allowed astronomers to “know what the stars were made of”, and which would be of great significance in
20th century studies of the universe. During her lifetime, Clerke was honoured with the Royal Institution’s Actonian Prize for science writing in 1893, and was made an honorary member of the Royal Astronomical
Society in 1903. A crater on the moon, near the landing site of Apollo 12, was named in her honour.