Reaching for the sky

The Comet Sweeper: Caroline Hershel’s Astronomical Ambition

by Claire Brock (Icon Books, 2007)

Caroline Hershel’s reputation has long been in the shadow of her brother William, who was the discoverer of Uranus and first president of The Astronomical Society of London (which later became the Royal Astronomical Society). She is rightly portrayed as the utterly reliable assistant without whom William Herschel would have achieved but a fraction of his discoveries and acclaim. But this biography The Comet Sweeper shines a light on Caroline’s achievements in her own right as well as looking at the obstacles and frustrations she had to overcome, in order to begin to fulfil her burning ambition.

On this page:

• Introduction
• Cinderella to Singer
• “I just want to be useful“
• A Lifelong Desire for Independence
• Elsewhere

Cinderella to Singer

Miss Herschel was uniquely honoured in her own lifetime through awards and renown. So it should be well-known that she was given the Gold Medal of the Royal Astronomical Society in 1828 and had become the first ever professional female scientist when she was granted an annual salary by King George III. She may not have been the first woman to discover a comet, and notched up 8 during her observing career, but made significant contributions through improving and expanding star catalogues, which in turn provided essential tools for other astronomers, not just her brother. In fact she was so famous that many members of Society would come to see her and William at work with their famous telescope, such that the frequency of visits became a source of irritations for her, detracting from her “sweeps” of the night sky.

But less well known (certainly to me) was her life before astronomy, when she survived extraordinary hardship and frustrations. Her family in the Electorate of Hanover, where she was born, were musicians. This was not a secure profession then (as now mostly) and as was the norm in the 18th century, girls in the household were expected to give way to their brothers. Her father encouraged her and taught her a little music but her uneducated mother treated her as a scullery maid. Caroline even described her early life as an Aschenbrödtle (Cinderella). This was no exaggeration, as the household were known to forget about her and leave her literally out in the cold while they had a family feast! Her eventual escape to England was therefore a major turning point in her life. But when she went to stay with William, he was working as a composer and musician and Caroline was to become a singer.

“I just want to be useful”

In everything Caroline turned her hand to, she was determined and diligent. Whether it was home tasks such as needlework, or learning mathematics or practising music, she was disciplined and talented, and made it her life’s ambition “to be useful”. Although William soon turned more towards developing his love for astronomy rather than musical composition, his sister actually achieved renown amongst the society of Regency Bath. She could have taken her singing career to another level, but instead began systematically supporting William with building and using telescopes. In the late 18th century there was a significant trend towards educated women rejecting the fad of romantic novels and taking an interest in mathematics, chemistry and astronomy. Long before women had opportunities to study these subjects on an equal footing with men, there was a hunger and indeed talent for learning, that was denied them for far too long.

The Herschels’ methods of working with the large telescopes required William to be perched high up on the framework of the instrument. He would call out observations to his sister either below or through an adjacent window. She would note everything along with marking accurate timings. In the morning she would not rest until the observations were written up, further laborious calculations completed and any updates to the available star catalogues made. Her work to integrate the observations with the existing catalogue of Flamsteed and over time her own observations, alongside William’s, significantly expanded Messier’s catalogue of nebulae With their better telescopes and Caroline’s careful methods they were able to improve the precision of the information.

Lifelong Desire for Independence

All this Caroline achieved while also running the household for her brothers. But in her astronomical work she was far from just an assistant, as is made plain by her discoveries of comets when William was away. And this was not luck or chance, but the result of her having developed several different formats and systems from the improving star catalogues, so that she (and others) could perform systematic horizontal or vertical “sweeps” of the sky, and more simply reference all the known astronomical objects expected.

This excellent little book by Claire Brock does not dwell on the scientific details – these are covered in many other ways – but provides a revealing context for the sister and brother whose work advanced astronomy in the late 17th and early 18th centuries. It tells the story of Caroline’s driving ambition to do something with her life, in defiance of the obstacles in her path. She is rightly celebrated as a scientist in her own right and for her courage and ambition deserves also to be held up as an icon of female advancement, on the road to liberation, suffrage and universal education. The world still has a lot to learn from her spirit and her achievements.

In the words of the President of the Royal Society, Sir Joseph Banks, Caroline Herschel herself had ‘advanc[ed] the science [she] cultivated with so much success’, through perseverence, stoicism, but also importantly, through ambition and a lifelong desire for independence.

Claire Brock (from the Conclusion of The Comet Sweeper)

Elsewhere

• Memoir and Correspondence of Caroline Herschel by Mrs. John Herschel (1879) – this is an important source for any account of Caroline Hershel’s life and work. It is available to read for free from The Project Gutenberg eBook of Memoir and Correspondence of Caroline Herschel, by Mrs. John Herschel
• The Age of Wonder: How the Romantic Generation Discovered the Beauty and Terror of Science by Richard Holmes (2008, HarperCollins)