Sweeper of the heavens, 1786
Yet raised only to sweep the house.
As this piece goes out, I will be on my way back from visiting the Royal Observatory at Greenwich, London with my kids. So how about something astronomical, related to the date?
I normally put the primary source after an introductory essay, but this is so short and snappy it can go right here (though there’s more detail below):
August 1.—I have counted one hundred nebulæ to-day, and this evening I saw an object which I believe will prove to-morrow night to be a comet.
2nd.—To-day I calculated 150 nebulæ. I fear it will not be clear to-night. It has been raining throughout the whole day, but seems now to clear up a little.
1 o’clock.—The object of last night is a comet.
3rd.—I did not go to rest till I had wrote to Dr. Blagden and Mr. Aubert to announce the comet. After a few hours’ sleep, I went in the afternoon to Dr. Lind, who, with Mr. Cavallo, accompanied me to Slough, with the intention of seeing the comet, but it was cloudy, and remained so all night.1
The writer in question is Caroline Herschel (1750–1848), the remarkably long-lived sister of the astronomer William (Wilhelm) Herschel with an impressive career of her own in the same field. She was not only the first known woman to have discovered a comet – see above – but also the first woman to receive a salary for being a scientist and the first to have a paper read at the Royal Society (a group which keeps cropping up in Histories). And much more besides.
Like her older brother, she was born in Hanover, Germany, but she had a tougher childhood – aged ten her growth was stunted by typhus and she lost sight in one eye, and she was expected to work as a household servant. William had fled to England in 1757 during war between Hanover and France, and soon established himself as a notable musician. After several years in the north of England, he moved to Bath in 1766 to take up a respected role as an organist, and in 1772 Caroline moved there to join him. She too was musically talented, but they also shared a growing enthusiasm for astronomy, with Caroline assisting William and from 1782 keeping a record book of her own observations. Between 1786 and 1797 she discovered at least seven comets, and was congratulated by the Astronomer Royal, Nevil Maskelyne.
Caroline kept numerous record books and ‘day-books’ with a mixture of her astronomical observations and other snippets of her life. She also wrote a memoir of her life in 1836, though it only covered the years 1755–75 before her most notable work. Only last year the manuscript of this was acquired by the Herschel Museum of Astronomy in Bath, in the building where she lived from 1777 with William and their other brother, Alexander; she stayed there until 1784.
Somewhat inevitably given the era, Caroline was somewhat in her renowned brother’s shade, a satellite to his planet, not always given the respect she deserved, at least until the accolades of her later life after he had died (in 1822). Some of the roots of this can be traced to her mother, in fact, who resisted efforts to educate her. But William did also nurture her talents – it was thanks to him that Caroline reached the heights of singing in oratorios by Handel and others as many as five nights a week in fashionable Georgian Bath. And her diligence in studying the night sky, sweeping the arc of the heavens for celestial bodies (“I swept from ten till one,” reads a typical day-book entry), both in aiding her brother and independently, helped advance scientific understanding enormously – between them, for example, the pair took the number of known nebulae from around a hundred to two-and-a-half thousand.
As I head off to Greenwich I shall think of her – in 1799, she spent a week at the Royal Observatory as Maskelyne’s honoured guest. (When she discovered her last comet, in 1797, she was so keen to share the information that she rode all night to give Maskelyne the details in person.)
But let’s return to the excitement of discovery, and a short chain of correspondence between Caroline and scientific luminaries of the day, back in 1786 when she caught sight of that ice ball in the heavens.2
Here is Caroline’s very matter-of-fact letter to Charles Blagden, Secretary of the Royal Society, on 2nd August 1786 (remember, too, that English was not her first language):
Sir,—
In consequence of the friendship which I know to exist between you and my brother, I venture to trouble you, in his absence, with the following imperfect account of a comet:—
The employment of writing down the observations when my brother uses the twenty-foot reflector does not often allow me time to look at the heavens, but as he is now on a visit to Germany, I have taken the opportunity to sweep in the neighbourhood of the sun in search of comets; and last night, the 1st of August, about 10 o’clock, I found an object very much resembling in colour and brightness the 27 nebula of the Connoissance des Temps,3 with the difference, however, of being round. I suspected it to be a comet; but a haziness coming on, it was not possible to satisfy myself as to its motion till this evening. I made several drawings of the stars in the field of view with it, and have enclosed a copy of them, with my observations annexed, that you may compare them together…
These observations were made with a Newtonian sweeper of 27-inch focal length, and a power of about 20…
Caroline wrote similarly to another keen astronomer, Alexander Aubert, ending her letter with typical modesty: “I hope, sir, you will excuse the trouble I give you with my vague description, which is owing to my being a bad (or what is better) no observer at all.”
Blagden was immediately appreciative of her discovery, and wrote back on 5th August:
… I believe the comet has not yet been seen by anyone in England but yourself. Yesterday the visitation of the Royal Observatory at Greenwich was held, where most of the principal astronomers in and near London attended, which afforded an opportunity of spreading the news of your discovery, and I doubt not but many of them will verify it the next clear night… it is not impossible that Sir Joseph Banks [the famed natural scientists who had accompanied Captain James Cook to Australia] and some friends from his house may wait upon you to beg the favour of viewing this phenomenon through your telescope.
And Aubert was more effusive still:
I wish you joy, most sincerely, on the discovery. I am more pleased than you can well conceive that you have made it, and I think I see your wonderfully clever and wonderfully amiable brother, upon the news of it, shed a tear of joy. You have immortalized your name, and you deserve such a reward from the Being who has ordered all these things to move as we find them, for your assiduity in the business of astronomy…
And next time, I’ll look at the chain of influence that came from Caroline and led to perhaps the biggest revolution in the history of science!
James Lind was her physician, and the man who worked out that citrus fruit cures scurvy – paid subscribers can read my piece about him here. Tiberius Cavallo (great name!) was a scientist friend.
The letters and extracts of Caroline’s day-books were all published in Memor and Correspondence of Caroline Herschel, published in 1876
This French publication is the oldest annual volume of astronomical tables in the world, founded in 1679 and still going today.
A remarkable woman, to be sure!