Biographies & Memoirs


Herschel Among the Stars


Sir Joseph Banks had predicted that British astronomy would go further than French ballooning. In the summer of 1785 William Herschel embarked on his revolutionary new project to observe and resolve the heavens with a telescope more powerful than ever previously attempted. His first move was to draft a preliminary technical specification for Banks to submit to the King. It was a monumental proposal.

What he intended to build was a telescope ‘of the Newtonian form, with an octagon tube 40 foot long and five feet in diameter; the specula [mirrors] of which it would be necessary to have at least two, or perhaps three, should be from 36 or 48 or 50 inches in diameter’.1 The telescope would have to be mounted in an enormous wooden gantry, capable of being turned safely on its axis by just two workmen, but also susceptible to the finest and most minute fingertip adjustments by the observing astronomer. The mirrors would weigh about half a ton each, and cost between £200 and £500. They would have to be cast in London and shipped by barge up the Thames for polishing.2 Casting would be a major feat of technology, and twenty workmen would be required to effect a continuous process of polishing with newly designed machinery.

The forty-foot would be higher than a house, extremely susceptible to wind, and very exposed to adverse weather conditions, especially frost, condensation and air-temperature changes, which could ‘untune’ the mirrors like musical instruments. The astronomer (Herschel was now approaching fifty) would be required to climb a series of ladders to a special viewing platform perched at the mouth of the telescope, from which a fall would almost certainly prove fatal. The assistant (Caroline) would have to be shut in a special booth below to avoid light pollution, where she would have her desk and lamp, celestial clocks, observation journals and coffee flasks. But she would see virtually nothing of the stars themselves.

Astronomer and assistant would be invisible to each other for hours on end, shouting commands and replies, although eventually connected by a metal speaking-tube. It would be rather as if they were the tiny crew of some enormous ship, one up on the bridge, the other below in the chart room, intimately dependent on each other but physically isolated. Perhaps this was the premonition of a new kind of vessel: a spaceship flying through the starry night.3

All this would require a new level of funding by the King. The estimate of expenses totalled £1,395, with an annual running cost of £150. This huge sum did not include Herschel’s annual salary of £200.4 When he submitted this enormous research-grant application, Herschel austerely did not promise any immediate results-more planets, more comets, more sightings of extraterrestrial life forms. Instead he tried to reassure Banks in the most sober terms: ‘The sole end of the work would be to produce an Instrument that should answer the end of inspecting the Heavens, in order more fully to ascertain their construction.5

It was one of Sir Joseph Banks’s most dramatic diplomatic coups that he had convinced the King to announce a grant by September 1785. The sum was a generous one: the entire construction costs and four years’ running expenses-a total of £2,000. The one implied proviso was that Herschel needed to come up with results by the end of 1789. In November 1785 Banks was already sending tactful enquiries through William Watson: ‘Sir Joseph Banks is come to Town, & expressed a wish to know from you what preparations you have made relating to the great Telescope, & how far you have proceeded in the work itself. He said that he was very desirous of knowing, that he might be enabled to give the King a history of your proceedings.’6

In fact there was no immediate progress that autumn. To Caroline’s dismay, Herschel had decided that his grand project required a new house with larger grounds for constructing and erecting the telescope, and more outbuildings for workshops. A first move from Datchet to Clay Hall, nearer to Windsor, had proved abortive when their new landlady objected to the cutting down of trees, and sought to raise the rent on the ingenious grounds that Herschel’s monster telescope, if it were ever built, would count as an ‘improvement’ to the house. Herschel wondered mildly if each new astronomical discovery would increase the valuation, and thereafter require a corresponding increase in the rent.

On 3 April 1786 they moved again (the Herschels’ third move in four years), to ‘The Grove’, a quite small and rather dilapidated country house on the edge of the tiny village of Slough, three miles north of Windsor. It was owned by a wealthy local family, the Baldwins, whose various relations also owned two local inns, the Dolphin and the Crown, and were extensive landowners in the district. The Crown was the main mail-coach halt on the London to Bath turnpike, now rerouted as the modern A4 through Slough. (The original sleepy road junction has become a pedestrianised section of the busy high street, though still known locally as ‘the Crown crossroads’.)

The youngest member of the family, Mary Baldwin, was a considerable heiress, and had married a retired London merchant, John Pitt, who was some twenty years older than herself. They decided to lead an easy-going country life, and had their own large, comfortable house less than a mile away from The Grove at the little village of Upton. They proved hospitable and friendly neighbours, and soon got to know the Herschels socially. John was in ‘a declining state of health’, so William would walk over at weekends, and sit talking to him in his well-appointed library. Caroline seems to have got on rather well with the Pitts’ son Paul, an only child who had just started at nearby Eton College.7

The Grove stood in secluded grounds, 200 yards south of the Crown Inn, on the east side of the road to Windsor. Though it was surrounded by trees, the ground dropped away sharply to the south, offering a good observational platform. It was also ideal for rapid communications with London and Maskelyne’s observatory at Greenwich, as well as remaining close to the King’s residence. Indeed the turrets of Windsor Castle could be seen from the terraced walk on the south of the property, a constant reminder of the expectations of the royal patron.8 The house itself was not large: four bedrooms and a servants’ attic. But it had extensive sheds and stables which were gradually converted into workshops and laboratories, and a wash house that became a forge. Above the stables were a series of haylofts which could be converted into a separate apartment. Caroline claimed these for her own. She had them roughly whitewashed, and put into use as a bedroom and a writing room, with a small outside staircase leading up to a flat roof from which she hoped to carry out her comet ‘sweeps’ in security and independently. This became her ‘cottage’ and occasional residence, a first step towards domestic independence at the age of thirty-six.

The Grove also had a large flat area of rough gardens in front of it, ideal for levelling and laying the extensive circular brick foundations of the wooden gantry for the forty-foot telescope. The brickwork was capped with Portland stone, though later this was cracked by frost and had to be sheathed in oak.9 As work progressed, Herschel had all the surrounding trees cut down, including a magnificent row of ancient elms, ‘to the grief of everyone who knew that sweet spot’, as one neighbour observed. Characteristically, Herschel took no notice of their objections.10 This scattered collection of buildings would later become known as ‘Observatory House’, and Herschel’s telescope would be marked on the first edition of the Ordnance Survey map for Berkshire in 1830.11

The launch of the new project changed the quiet rhythm of the Herschels’ lives. The spring of 1786 was ‘a perfect Chaos of business’, as Caroline put it with a certain relish: ‘If it had not been sometimes for the intervention of a cloudy or a moonlight night [bad for stellar observation], I know not when my Brother (or I neither) should have got any sleep; for with the morning came also the workpeople of which there were no less than between 30 or 40 at work for upwards of 3 months together, some employed with felling and rooting out trees, some digging and preparing the ground for the Bricklayers who were laying the foundation for the telescope, and the carpenter in Slough with all his men.’12

News of the proposed monster telescope brought a steady stream of visitors to Slough: men of science, academics from the universities, foreign tourists, and too many dignitaries from the Court. Caroline would grow increasingly impatient at their tendency to interrupt Herschel’s work. She developed her own laconic way of registering this impatience: ‘Professor Sniadecky often saw some objects through the 20 foot Telescope, among others the Georgian satellites. He had taken lodgings in Slough for the purpose of seeing and hearing my Brother whenever he could find him at leisure. Himself was a very silent man.’13 She was always happy, however, to welcome old friends like William Watson and Nevil Maskelyne, and new supporters from the Royal Society like Charles Burney (who was also in favour of hot-air balloons). Americans were notably well-received.

Sometime in the summer of 1786 the fifty-year-old John Adams, graduate of Harvard University, man of science and future second President of the United States, turned up one morning uninvited at The Grove. He was shown round all Herschel’s new telescopes, and they embarked on an impassioned discussion of the possibility of extraterrestrial life, and the moral implications of there being a ‘plurality of worlds’. This was the sort of metaphysical debate that Herschel had once had with his brother Jacob, touching on the speculations of European authors like Fontenelle and Huygens, but which he tended to avoid with his English contemporaries. Neither Herschel nor Caroline recorded exactly what was said, but it is clear from his own diaries that Adams would have put lively and unorthodox views: ‘Astronomers tell us that not only all the Planets and Satellites in our Solar system, but all the unnumbered Worlds that revolve round the fixt Stars are inhabited…If this is the case all Mankind are no more in comparison [with] the whole rational Creation of God, than a point in the orbit of Saturn.’

Like the poet Shelley a generation later, Adams liked to press this argument one stage further. If astronomy discovered extraterrestrial civilisations, then surely the earth-based doctrines of Christian redemption became absurd, or at least mighty inconvenient for the Lord. ‘I ask a Calvinist, whether he will subscribe to this alternative: EITHER God Almighty must assume the respective shapes of all these different Species, and suffer the penalties of their Crimes, in their stead; OR ELSE all these Beings must be consigned to everlasting Perdition?’14 

Amidst all the bustle of visitors and workmen, Herschel was despatched by royal command in July 1786 to deliver and erect one of his ten-foot telescopes, as King George’s special gift to the University of Göttingen, which was fast becoming the centre of scientific studies in Germany. His brother Alexander was to accompany him as business manager. This was both a great honour and a great inconvenience, and for the first time in her life Caroline was left wholly in charge of both the construction work on the forty-foot and the continuing observation programme of nebulae and double stars. Currently they had completed 572 sweeps, identified 1,567 nebulae, and found two tiny new moons orbiting Georgium Sidus (a discovery that particularly amused the King).15

Caroline’s first response was thoroughly domestic. She started a new day book, neatly headed it ‘Book of Work Done’, drew a careful set of parallel columns, and recorded her inventory of tasks.

July 3rd 1786. My Brothers William and Alex left Slough to begin their journey to Germany…By way of not suffering too much by sadness, I began with bustling work. I cleaned the brass work for the 7 and 10 feet telescopes and put curtains before the shelves to hinder the dust from settling upon it again. I cleaned and put the [mirror] polishing room in order and made the gardener clean the work-yard, put everything in safety and mend the Fences.

She would not tolerate idling among the workmen, who evidently caused difficulties. The gardener was reprimanded for lolling about the lawns: ‘he gave me the name of “Stingy—” in the village, because I objected to his being there when not wanted’.16 It would be interesting to know what the ‘—’ stood for: the fact that Caroline was female, foreign, diminutive, unmarried, disciplined, or brilliantly gifted perhaps?

That afternoon she did needlework and went shopping in Windsor; when she got back she was mortified to find ‘there had been four foreign Gentlemen looking at the instruments in the garden, but did not leave their names’. Later unannounced visitors that month included Nevil Maskelyne and his wife, three members of the great Dolland telescope family, the Duke of Saxe-Gotha, Tiberius Cavallo (the balloon expert from the Royal Society), her friend Dr James Lind, the Prince Resonico and the Plumian Professor of Astronomy at Cambridge, Dr Antony Shepherd. The question of visitors became more awkward as July progressed, and for the first time made Caroline aware of the social anomaly of her position. ‘I was often put into great perplexity by such self-inviting visitors; for I could only look upon myself as an individual who was neither Mistress of her Brother’s house, nor of her Time, and for that reason could, nor would, ever give invitations.’ She also found the endless ‘gossipings’ of Alexander’s pretty but ‘foolish’ new wife, who came over from Bath, intolerable.17

By the end of July Caroline had decided that the only way to remedy this situation was to insist on her own quite separate regime. She would be an astronomer, not a housekeeper. She would check over the calculations of William’s nebulae by day, and make her own sweeps up on the roof by night. She would go to bed late (often just before dawn light, around 4 a.m.) and get up late (but always in time to pay the workmen after breakfast). She even wrote William a little imaginary letter about this in her ‘Book of Work Done’. In this case it was to be work she would not do. ‘I find I cannot go fast enough with the registering of sweeps to be serviceable to the Catalogue of Nebulua. Therefore I will begin immediately to recalculate them, and hope to finish them before you return. Besides I think the consequences will be bad of registering the sweeps backwards.’18Thus liberated from the nightly duty of William’s sweeps, her ‘Book of Work Done’ began to fill with her own astronomical observations. Symbolically she recorded on 30 August winding up the ‘Sidereal Time Piece’, the big brass chronometer used to fix stellar positions.

Three summers previously William had built Caroline a special two-foot Newtonian reflector, mounted within an ingenious wooden box-frame. Because of its large aperture, its tube appeared much fatter, heavier and stubbier than normal reflectors of this type: a rotund, almost jovial presence, but not in the least awkward to handle. Suspended from a pivot at the top of the box-frame, the telescope could be precisely raised or lowered by a system of pulleys operated by a large brass winding handle at the bottom. These adjustments were easy to make, and extremely fine. The whole ‘contrivance’ was set on a solid portable wooden stand, constructed like a three-legged stool, and exactly carpentered to bring the Newtonian viewing lens precisely to the level of Caroline’s eye. It also allowed a workman (or Caroline herself) to carry the telescope and stand in two sections, and position it wherever required, downstairs in the garden or upstairs on the flat roof.19

This beautiful instrument was designed specifically for its huge light-gathering power and its wide angle of vision. The mirror was 4.2 inches in diameter (the size more usually placed in the seven-foot reflectors), with a large observational field of over two degrees. The magnification was comparatively low at twenty-four times. As with modern binoculars, this combination of low power with a large viewing field allowed the observer to see faint stellar objects very brightly, while placing them within a comparatively wide context of surrounding stars. In effect, Herschel had constructed for Caroline a hunter’s telescope.

It was a deliberate challenge. The instrument was not suitable for deep space, but it was perfectly designed to spot any strange or unknown object moving through the familiar field of ‘fixed stars’. It was designed to find wanderers and messengers coming into the solar system. In other words, to catch new planets or new comets. It eventually became famous as ‘Miss Herschel’s small sweeper’, and would be joined within two years by ‘Miss Herschel’s large sweeper’.20

On 1 August 1786, only two nights after starting her new sweeps, Caroline thought she had spotted an unknown stellar object moving through Ursa Major (the Great Bear constellation). It appeared to be descending, but barely perceptibly, towards a triangulation of stars in the beautifully named Coma Berenices (‘Berenice’s Hair’, as celebrated in Pope’s poem ‘The Rape of the Lock’). To find something so quickly, and in such a familiar place (the Great Bear or Big Dipper being the first stop of every amateur stargazer wanting to locate the Pole Star), seemed wildly unlikely. Caroline’s Observation Book conveys meticulous caution, but also remarkable certainty.

Unable to calculate the mathematical coordinates of the object, she accompanied her observations with a series of three neat drawings or ‘figures’, over an eighty-minute time lapse. These showed the circular viewing field of her telescope, with an asterisk shape very slightly changing position relative to three known fixed stars.

August 1st 1786. 9 hours 50 mins. I saw the object in the center of fig.1 like a star out of focus while the others were perfectly clear. The sec. star is very faint but the weather is hazy, and in a clearer night undoubtedly some more will be visible…11 hours 10 mins. I think the situation is now like in Fig.3 but it is so hazy that I could only imagine I saw the second star & the preceding I could not see at all. The comet is about half way between 53 and 54 Ursa maj. and some stars which I found after looking over the map at leisure to be 14, 15, and 16 Coma Berenices…21

Caroline does not remark that her comet was moving from a male to a female constellation, a fact which might have well have struck her as peculiarly appropriate. But the account written into the ‘Book of Work Done’ catches something of her growing excitement. The drudgery of daytime calculation in her study was overtaken by the tantalising expectations and frustrations of the nights up on the flat roof.

August 1st. I have calculated 100 nebulae today, and this evening I saw an object which I believe will prove tomorrow night to be a Comet. August 2nd. Today I calculated 150 nebulae. I fear it will not be clear tonight, 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. August 3rd. I did not go to rest till I had written to Dr Blagden [at the Royal Society] 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. August 4th. I wrote today to Hanover, booked my observations and made a fair copy of 3 letters…The night is cloudy. August 5th. I calculated nebulae all day, paid the smith…The night was tolerably fine and I SAW THE COMET.22

Both Aristotle and Galileo had thought comets were low-level atmospheric phenomena, perhaps lower than the moon. The study of comets was improved by the sixteenth-century Danish astronomer Tycho Brahe, but transformed in 1682 when Edmund Halley famously calculated that the Great Comet of that year, subsequently named after him, would reappear in 1759. It was then finally accepted that comets were outer-space objects that moved in extreme elliptical orbits round the sun, and swung far beyond the known planets. Yet they were still mysterious: of unknown origin and composition, various in their appearance, irregular and alarming in their habits. A reassuring popular view, that they were celestial table-waiters, supplying the planets with moisture and the sun with fire, was expressed by James Thomson in his poem The Seasons (1726-30).

From his huge vapouring train perhaps to shake

Reviving moisture on the numerous Orbs,

Thro which his long elipsis winds; perhaps

To lend new fuel to declining Suns,

To light up Worlds, and feed the etherial Fire.23

By the mid-eighteenth century only about thirty comets had been identified and recorded in the annual French catalogue La Connaissance des Temps. The greatest comet-hunter of the age, Charles Messier, had personally found about half of these, and so comet-hunting was generally regarded as a French speciality. Caroline’s discovery-even if it had been her only one-would have been an important contribution internationally. Comets (meaning ‘hairy stars’) were significant because they were the only celestial objects which came in from beyond the known solar system, and therefore carried possible information about conditions further out in space.

The fact that the elliptical path of periodic comets could be calculated according to Newton’s laws, and their returns predicted scientifically, seemed to prove that their traditional role as portents of events on earth (usually of sudden disasters) was a meaningless superstition. So the comet that appears in the Bayeux Tapestry turned out to be Halley’s on a previous periodic visit; it reappeared without disaster in 1986, and is next scheduled in 2061. However, new comets such as that of 1811 still caused a great popular stir. Adam Smith noted in his Philosophical Enquiries (1795): ‘the rarity and inconstancy of their appearance, seemed to separate them entirely from the constant, regular, and uniform objects in the Heavens’.24 

It is revealing that Caroline was too excited to sleep, and that in the absence of Herschel, almost her first reaction was to contact her friend and confidant Dr James Lind, who had spoken up for her over the treatment of her wounded leg. The note dashed off to Alexander Aubert is disarming in its modesty, but hints at her sense of obstacles overcome. ‘I hope, Sir, you will excuse the trouble I give you, with my wag [vague] description, which is owing to my being a bad (or what is better) no observer at all. For, for the last three years past I have not had an opportunity to look as many hours in the telescope. Lastly I beg you Sir, if this Comet should not have been seen before to take it under your protection.’25

Privately she still had grave doubts about her own observation skills, and wrote a frankly unscientific ‘Memorandum’ in her Observation Book, admitting that the comet seemed to have a mind of its own, and was not behaving at all as it should. ‘I am at a loss what to think of the path which this Comet may have, by the figures [drawings] of last night it seemed to move downwards but tonights figures show just the contrary. In my letter to Mr Aubert I avoided taking notice of this circumstance…for my wish was only to say what was just necessary by way of delivering it into better hands.’26

Her letter to Charles Blagden, Secretary to the Royal Society and Banks’s right-hand man, produced a dramatic reply by return of post: ‘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 that many of them will verify it the next clear night. I also mentioned it in a letter to Paris, and in another I had occasion to write to Munich.’27

The verification of Caroline’s comet was achieved much more rapidly than Herschel’s planet had been. Its movement through Coma Berenices was relatively easy to ascertain, and its fine hazy tail or coma was unmistakeable. Its cometary status was quickly confirmed by Nevil Maskelyne, and on the following evening, 6 August, an impromptu top-level deputation rode down to Slough. Caroline was astonished to receive Blagden himself, Sir Joseph Banks and the MP Lord Palmerston, demanding to see her comet through her special sweeper telescope. Gratefully, she recorded that the evening was ‘very fine’, and everyone was able to get a glorious view of the new visitor, both with her small sweeper and the higher-powered seven-foot telescope.28

Banks was in one of his triumphal moods, and announced that her historic letter would be immediately published in the Philosophical Transactions, where it duly appeared-though after the usual bureaucratic delay-on 9 November, as ‘An Account of a New Comet. In a Letter from Miss Caroline Herschel’. This was her first ever publication by the Royal Society, and an almost unheard-of rarity for a female correspondent.29 Maskelyne was also full of praise, patriotically recruiting Caroline into the new ranks of British astronomy at once. ‘I hope that we shall, by our united endeavours, get this branch of astronomical business from the French, by seeing comets sooner and observing them later.’30 Alexander Aubert, realising the personal significance of the find for her, struck a more intimate note: ‘I wish you joy most sincerely of the discovery. I am more pleased than you can well conceive that you have made it-and I think that your wonderfully clever and wonderfully amiable Brother, upon the news of it, shed a tear of joy. You have immortalized your name.’31

The idea of a female astronomer intrigued people. When William returned from Germany ten days later, on 16 August, he found that Caroline had become something of a celebrity. In September he was summoned to Windsor specifically ‘to exhibit to His Majesty and the royal family the new comet lately discovered by his sister, Miss Herschel’.32 Fanny Burney the novelist, then a lady in waiting to Queen Charlotte, had evinced little previous interest in the stars. But she now suddenly discovered a lively fascination with astronomy, and leaped at the chance to abandon a game of royal piquet and join the viewing party on the Windsor terrace.

To Fanny’s disappointment, Caroline herself was not there (she avoided the Court whenever possible). But the session was interesting ‘for all sorts of reasons’, the glimpse of the comet-catcher’s brother being as fascinating as the comet. ‘We found [Herschel] at his telescope. The comet was very small, and had nothing grand or striking in its appearance; but it is the first lady’s comet, and I was very desirous to see it. Mr Herchel then showed me some of his newly discovered universes, with all the good humour with which he would have taken the same trouble for a brother or a sister astronomer; there is no possibility of admiring his genius more than his gentleness.’33 Fanny was struck above all by Herschel’s total lack of arrogance: ‘he is perfectly unassuming…yet openly happy in the success of his studies’. But she wondered about his relationship with his reclusive sister.

Intrigued, she soon after persuaded her father to take her on a private visit to Herschel’s observatory at The Grove on 30 December 1786. The ‘great and extraordinary man’ received them in his genial manner with open arms, showed them over the unfinished forty-foot telescope in the garden, and talked unguardedly over tea about ‘the new views of the heavenly bodies and their motions’ which it would reveal. Fanny was entranced. She exclaimed excitedly: ‘he has discovered fifteen hundred universes! How many more he may find who can conjecture?’ Charles Burney was also inspired by this visit, and began to compose an extensive ‘Ode to Astronomy’ in Herschel’s honour, which he threatened to read out loud at future convivial suppers.34

By contrast, Caroline Herschel was rather silent, and much more of a puzzle. Fanny Burney evidently tried hard, but failed to get on terms with her. ‘She is very little, very gentle, very modest, very ingenuous; and her manners are those of a person unhackneyed and unawed by the world, yet desirous to meet and return its smiles.’ Those shy smiles seemed to be the extent of their communication. Equally, Caroline did not mention Fanny at all in her day book.35

Other visitors to The Grove had better luck. The German novelist Sophie von La Roche gushingly introduced herself to ‘the great man’s sister, who accompanies him on his path to immortality’. Perhaps Caroline found her fellow-countrywoman easier to placate than Fanny Burney, and made the inspired gesture of picking a bunch of daisies growing in the grass at the foot of the twenty-foot, and presenting them to her as a scientific keepsake. No doubt Sophie was intended to compare them to a star cluster beyond the Milky Way.36

Surprisingly, it was Nevil Maskelyne who began to take Caroline’s technical prowess most seriously. A correspondence sprang up between them, and slowly blossomed over the next decade. He later wrote a detailed description of her ‘large’ Newtonian sweeper and her method of working with it. This telescope, built in 1791, was a five-foot reflector with an even bigger aperture of 9.2 inches, but the same low magnification of twenty-five to thirty times, designed for still more effective comet-hunting. Its field of view, being slightly narrower than that of the two-foot sweeper at 1.49 degrees, required even greater familiarity with smaller patterns of the surrounding stars.37 Maskelyne remarked in passing that, like her brother, Caroline knew all the nebulae in the Connaissance des Temps instantly, and sight-read the night sky.38

During these same years Caroline was intensely involved in the final stages of setting up the great forty-foot telescope, intended as the climax of Herschel’s observation work on the nebulae. While continuing her regular night work as assistant on the twenty-foot, she was also helping to organise a vast team of workmen during the day, overseeing the accounts, and trying to bring some order to Herschel’s ever-increasing stream of distinguished and demanding visitors. In autumn 1787 these included the great French astronomer Pierre Méchain, director of the Royal Observatory in Paris and influential editor of the Connaissance des Temps. Praising Herschel for his preparatory work on the forty-foot, he also referred gallantly to ‘Miss Caroline, your worthy sister, whose celebrity will shine down through the ages’.39 When she discovered a second new comet in December 1788, any question of beginner’s luck melted away even in England.40 Her reputation continued to grow, especially in France and Germany.

Caroline remembered 1786-88 as the most intense and exciting years of her and William’s lives. They were both in their prime: in 1786 he was a vigorous forty-seven, she an animated and increasingly self-confident thirty-six. Their teamwork had never been closer. Thanks to Caroline, Herschel published over a dozen new papers with the Royal Society. (‘Very seldom could I get a paper out of his hands in time enough for finishing the copy against the appointed day for its being taken to Town.’41) Their great catalogue of nebulae had long since overtaken Flamsteed, and now stood at over 2,000 clusters, her own reputation as ‘comet-hunter’ gave her an independent scientific standing, and above all the great forty-foot telescope held out the promise of immense new discoveries. Sir Joseph Banks, the Astronomer Royal and the King himself all supported them. Sir William Watson commissioned a bust of Herschel for the Royal Society. Perhaps they would find more planets, new life elsewhere in the solar system, or even new civilisations among the galaxies. By 1789 they would certainly better understand how the universe had been created than at any previous time in history. This moment of scientific optimism coincided with the political optimism in Britain and France. In 1789 the Bastille would fall, and the Rights of Man would be declared.

Caroline’s picture of her brother at this period is heroic, but also unintentionally disturbing in its impression of his single-mindedness. The gentle, humorous, sociable man that Fanny Burney had observed is very little in evidence. Here instead was the man who cut down trees. He was in the grip of his dreams, ruled by a new kind of scientific obsession, intensely focused, workaholic, self-denying. He was driving, driven, indefatigable, omnipresent: ‘The garden and workrooms were swarming with labourers and workmen, smiths and carpenters going to and fro between the forge and the forty-foot machinery, and I ought not to forget that there was not one screw-bolt about the whole apparatus but what was fixed under the immediate eye of my brother. I have seen him lie stretched many hours in a burning sun, across the top beam whilst the iron work for the various motions was being fixed. At one time no less than twenty-four men (twelve and twelve relieving each other) kept polishing [the mirrors] day and night; my brother, of course, never leaving them all the while, taking his food without allowing himself time to sit down to table.’42

The subliminal image of Herschel almost crucified along the top beam of his telescope frame could not have been deliberate. Yet amidst all the bustle and excitement, Caroline slowly became aware of a growing financial crisis, which threatened to bring the entire project to a halt and wreck their fortunes. Over £500 had been wasted on the casting of a first, faulty mirror, a setback so severe that Alexander had urged the mirror’s ‘secret destruction’ because it called into question the whole viability of their casting techniques.43 Herschel had also seriously underestimated the costs of constructing the revolving gantry and paying the workmen for polishing the mirrors. Despite the sales of telescopes, they were threatened by bankruptcy. The whole glorious project could collapse in disaster and humiliation. By the summer of 1787 Herschel had to consider the delicate business of a new application to the King.

It was once again Sir Joseph Banks, the master of scientific diplomacy, who came to his aid. Although the huge half-ton mirrors were not yet finished, there was still a lot to see at The Grove: the great wooden gantry was partly installed on its turntable, now over seventy feet high, zone clocks and micrometers were assembled, and above all the enormous metal tube of the telescope was lying on its side, slumbering on the grass supported by wooden chocks, and ready to be winched into position. It was the moment, urged Banks, to give a Royal Telescope Garden Party.

Accordingly, on 17 August 1787 an impressive cortège of royal carriages rattled down from Windsor Castle, and Herschel and Caroline played host for the afternoon to a glittering party of dignitaries. The company included King George III and Queen Charlotte, the Duke of York, the Princess Royal, the Princess Augusta, the Duke of Queensberry, the Archbishop of Canterbury, many lords and ladies in waiting, a number of foreign visitors, and several distinguished Fellows of the Royal Society, although Banks himself seems to have remained tactfully absent. It was an impressive display which had the subtle effect, just as Banks would have foreseen, of further publicly committing the King to the scheme for which he was the acknowledged benefactor.

It also provided the occasion for another of the royal witticisms, a great additional gain. Caroline remembered it well even fifty years later. ‘One anecdote of the old tube…Before the optical parts were finished, many visitors had the curiosity to walk through it, among the rest King George III and the Archbishop of Canterbury: following the King, and finding it difficult to proceed, the King gave him his hand, saying, “Come, my Lord Bishop, I will show you the way to heaven.”’44

Now was the precise psychological moment to apply for the royal top-up grant. Herschel drafted a long letter to Banks for submission to the King, explaining the financial shortfall, the replacement of the faulty first mirror, the technical requirements of the gantry (now to be eighty feet high), and the fact that he expected no immediate profits except purely scientific ones. In an elegant formula probably devised by William Watson (if not by Banks himself), Herschel stated that his sole aims were ‘the advancement of astronomy, the honour of a liberal Monarch, and the glory of a nation which stands foremost in the cultivation of arts and sciences’. All details were then costed. The new sum required was huge: £950. But there were also, of course, the continuing running costs, which he estimated could (with careful economies) be kept at £200 per annum. If this increased grant was again assumed to cover operations until 1789, then the total requested (though not specifically stated) was in the region of £1,400-a very large amount indeed.45

Amazingly, Herschel did not stop there. He also raised through Banks something entirely new: the question of a separate royal stipend for Caroline as his official ‘astronomical assistant’. No British monarch had ever granted a woman a salary, or even a pension, for scientific work before. The very idea that Caroline might be eligible was as novel as that she might be elected to a Fellowship of the Royal Society, or to a professorship at Oxford or Cambridge or Edinburgh. The one concession Herschel made to convention (again probably advised by Banks himself) was that this stipend might come officially from Queen Charlotte. His phrasing was a fine mixture of reason, politesse and provocation. It also contained the interesting claim that the idea for the request had originally come from Caroline herself. She was after all the ladies’ comet hunter.

You know, Sir, that observations with this great telescope [the forty-foot] cannot be made without four persons: the Astronomer, the Assistant, and two workmen for the motions. Now, my good industrious Sister has hitherto supplied the place of Assistant, and intends to continue to do that work. She does it indeed much better, to my liking, than any other person I could have, that I should be very sorry ever to lose her from that office.

Perhaps our gracious Queen, by way of encouraging a female astronomer might be enduced to allow her a small annual bounty, such as 50 or 60 pounds, which would make her easy for life; so that if anything should happen to me she would not have the anxiety upon her mind of being left unprovided for.

She has often formed a wish but never had the resolution of causing an application to be made to her Majesty for this purpose. Nor could I have been prevailed upon to mention it now, were it not for her evident use in the observations that are to be made with the 40 foot reflector, and the unavoidable increase of the annual expense which, if my Sister were to decline, that office would probably amount to nearly one hundred pounds more for an assistant.46

Herschel made no bones about the fact that a female assistant, even his sister, would cost half as much as a male. It is possible to be indignant about this, but contemporary standards must be taken into account. Female domestic servants were paid £10 per annum, while a highly trained governess like Mary Wollstonecraft was paid £40 per annum by Lord Kingsborough in 1787. In fact a £60 stipend would have been handsome, exactly one-fifth of that paid to the Astronomer Royal. In Europe women who wanted to pursue science, like Voltaire’s beautiful mathematician Madame du Châtelet, or later Marie-Anne Paulze (Madame Lavoisier), simply had to have supportive or (even better) dead husbands, or private incomes. In Britain they had to be schoolteachers or children’s textbook writers, preferably both: like Margaret Bryan (astronomy), Priscilla Wakefield (botany) or Jane Marcet (chemistry). Only in the next generation was it possible to have a career like the physicist Mary Somerville, and (eventually) have an Oxford college named after you. But then, Caroline did live long enough to exchange letters with Mary Somerville drily remarking on this situation.47

Six days after the memorable Telescope Garden Party, on 23 August, the King summoned Banks to the palace. His Majesty informed him that he would renew the grant at nearly double Herschel’s requested sums, for a total of £2,000-with an additional £50 per annum for Caroline for life. Here was true royal largesse. It also marked a social revolution: the first professional salary ever paid to a woman scientist in Britain.

But the gift came with a royal sting. The Telescope Garden Party had backfired. The King told Banks that he was annoyed at being placed in such a compromising position by the Herschels. His generosity had been taken advantage of, he had anyway expected quicker results, and in no circumstances would he ever provide a penny more towards the telescope. There were no royal witticisms.

Even Banks was shaken by this royal outburst, later described as a ‘Storm’. It may perhaps have taken the alarming form of an early temper tantrum, since George III’s madness would declare itself the following year. Banks privately summoned Herschel to Soho Square as early as possible the following morning. He was uncharacteristically tight-lipped: ‘I have this moment seen the King, who has granted all you ask but upon certain conditions which I must explain to you.’48

The exact nature of these conditions was never put into writing, but probably referred to accounting of expenses, and the timing of future payments. Certainly the Herschels’ account books now became minutely detailed, and included such things as the cost of the workmen’s beer at lunchtime, and of ‘four or five’ individual candles burned each night.49 Caroline later called the stipulations ‘ungracious’, and said they came with a blunt message ‘that more must never be asked for’. They were sufficiently severe for Herschel to consider actually refusing the whole grant, as his old friend William Watson immediately wrote offering to send him ‘one or two hundred pounds’ instead. Herschel was dismayed at the unexpected turn of events; and for a few days gloomily considered abandoning the whole project. Caroline, despite-or perhaps because of-the success of her own application, was positively indignant. ‘Oh! How degraded I felt even for myself, whenever I thought of it!’50

Wiser counsels eventually prevailed. As Banks must have pointed out, the grant was, after all, spectacularly generous; and the future of astronomy in Britain was at stake. He may also had warned Herschel, in confidence, about the King’s fragile mental state. Watson sent a long, soothing letter on 17 September, urging a larger perspective, a wider field of view: ‘I most sincerely sympathise with you, & feel in some measure as you must feel at the unworthy treatment you (& I may add Science) has received. But I sincerely hope by the latter part of your letter that the Storm is passed…Let me hope, my dear Sir, that this affair has ceased to give you inquietude, & has not lessened your zeal for Science. Remember you have much cause for comfort & even of exultation. By your great discoveries…you have gained a high and universal reputation.’51

Herschel’s anger at the King’s peremptory attitude gradually faded, as the circumstances of his illness became known. Caroline found it less easy to forgive. She eventually blamed George’s courtiers. ‘I must say a few words of apology for the good King, and ascribe the close bargains which were made between him and my Brother to the shabby, meanspirited advisors who were undoubtedly consulted on such occasions.’ By contrast, Sir Joseph Banks remained ‘a sincere and well-meaning friend to the last’.52

Relations between Slough and Windsor never quite recovered their initial warmth, and it was only with the advent of the Prince Regent that further grants and honours were to be resumed, over twenty years later. Herschel was to be awarded a late knighthood in 1816, but his £200 stipend as the King’s Astronomer at Windsor remained unchanged for the next three decades, by which time wartime inflation had virtually halved its value.53

Gradually exultation and the hectic regime were resumed. ‘From this time on the utmost activity prevailed to forward the completion of the 40 foot…and several 7 foot telescopes were finished and sent off.’ A new optical workman was hired to oversee the polishing, and an enormous second mirror was successfully cast, much thicker than the first, and weighing in at nearly a ton. The quarterly instalment of Caroline’s royal stipend was promptly delivered in October 1787, precisely £12.10s. It was her first ever professional payment: as she proudly noted, ‘my Salary’. The ‘astronomical assistant’, for all her protests about royal behaviour, was evidently thrilled. It was ‘the first money I ever in all my life thought myself to be at liberty to spend to my own liking. A great uneasiness was by this means removed from my mind…For nothing but Bankruptcy had all the while been running through my silly head.’54

In November Pierre Méchain and Jacques Cassini came from Paris to inspect the preparations for the forty-foot, news of which was spreading across Europe. They also observed many of Herschel’s ‘new universes’ through the twenty-foot, and went away thoughtful and deeply impressed.55

At about this time, before the forty-foot was finally mounted, the Herschels gave a celebratory banquet which spilled out from the house, across the lawn and finished up with a kind of musical crocodile, dancing into one end of the tube and out the other. It must have been an extraordinary moment, and Caroline was in the highest spirits: ‘God Save the King was sung in it by the whole company, who got up from dinner and went into the tube, among the rest two Miss Stowes, the one a famous pianoforte player.’ Friends picked up oboes, ‘or any other instrument they could get hold of’, and accompanied the singing and dancing. ‘I, you will easily imagine,’ recalled Caroline fondly, ‘was one of the nimblest and foremost to get in and out of the tube.’56


It was a moment of hilarity and the highest spirits. Yet perhaps Caroline’s nimble dancing ‘in and out of the tube’ disguised a certain anxiety. Towards the end of 1787 her emergence as a serious astronomer in her own right was threatened by a crisis in her relations with William that she must have long dreaded. The great brother-sister team was threatened by Herschel’s growing friendship with an attractive neighbour. This woman was none other than the thirty-six-year-old Mrs Mary Pitt of Upton.57

Herschel and Caroline had often walked over to Upton village on summer afternoons to take tea with the Pitts in their handsome brick-floored parlour, before beginning their long nights of stellar observation. The little path was less than a mile long, eastwards along the escarpment and between large, scented hayfields.58 It made an idyllic walk, especially when they were coming back in the early evening, with Venus setting in the western sky.

Mary’s husband, John Pitt, was frail, and he died in September 1786. That winter the Herschels’ teatime visits had become more regular, as a sharp-eyed neighbour, Mrs Papendiek, noticed. ‘Widow Pitt, poor woman, complained much of the dullness of her life, and we did our best to cheer her, as did also Dr Herschel, who often walked over to her house with his sister of an evening, and as often induced her to join his snug dinner at Slough. Among friends it was soon discovered that an earthly star attracted the attentions of Dr Herschel.’ The ‘star’ innuendo was an obvious one to make, but the true world of English provincial gossip was revealed in that little word ‘snug’.59

Gossip did not concern Mary Pitt. She was a large, plain, kindly woman, whose friends described her as ‘sensible, good-humoured and unpretending’. An oval miniature portrait shows her in simple country clothes, with her hair caught up in a knotted scarf, as if about to go on a long country walk. But she is also wearing a good, expensive necklace, and her large eyes suggest a certain thoughtful and determined air.60 She was a woman of independent means, but with few social ambitions, and no wish to live in town. Altogether she had a calm, pleasant, down-to-earth quality that might well have appealed to a distracted astronomer, increasingly driven by his work and his celebrity. Now she was vulnerable, and perhaps that made her doubly attractive to a man like Herschel. Her only son, Paul, was often away from home at Eton; and her elderly mother, the wealthy Mrs Baldwin, was widowed, invalid and demanding. Mary Pitt was lonely, and William Herschel, in his own way, was lonely too.61

By early spring 1787 there began to be talk of marriage. Caroline, for whom the evening walks to Upton with her brother had seemed so innocent, was evidently unprepared for this, and shaken once she realised what was afoot. She wrote nothing in her journal, but there are tiny indications of increasingly erratic emotional behaviour. In February, when Alexander’s wife died in Bath, she reacted with quite uncharacteristic violence. Her sister-in-law’s death was not unexpected, as she had been ill for some time, and anyway Caroline had never been close to her, regarding her as a bore and a gossip. But according to Herschel, who responded phlegmatically enough himself, Caroline was almost hysterical with grief. As he told Alexander: ‘Having been up all night Carolina was still in bed when your letter came. Poor Girl, she has hardly had a dry eye today; however our late sister’s health had been so very bad we cannot say she died unexpectedly and therefore we should not grieve too much…Carolina is not well enough to write today but will either tomorrow or next day endeavour to take up the pen. Last week I went to London to cast a 40 foot speculum, much thicker and stronger than my present one.’62

Herschel himself was evidently looking towards the future. He foresaw no financial problem in marriage. On the contrary, Mary Pitt turned out to be much wealthier than he had supposed. She had inherited a life interest in her husband’s estate (her son Paul was left a handsome £2,000 to be going on with), and her difficult mother had promised to bequeath her all her properties (including the Crown Inn). It was calculated that this alone would bring rents worth at least £10,000 per annum.63 At the very least, the future financing of the forty-foot would not be put at risk. Though Herschel had never been a fortune-hunter (and would never cease manufacturing telescopes), this must have been a vital consideration, especially after his contretemps with the King.

But what of Caroline? The new situation posed delicate questions of social roles, domestic powers and emotional loyalties, which Herschel tried hard to negotiate. His initial proposal was that he would continue his working establishment, with Caroline as mistress of The Grove, while his married home would become Upton, with Mary. In effect he was proposing a double life: as a husband in one place, and as a man of science in the other. This seemed eminently reasonable to him, and was perhaps not unsatisfactory to Caroline.64

It would take one of Jane Austen’s unwritten novels to do justice to the social and emotional complications of this unfolding situation. The path between Upton House and The Grove must have been the scene of much drama. Herschel himself was evidently divided between attraction to Mary Pitt, loyalty to his sister and dedication to his science, none of which he hoped need be exclusive. Caroline had much to fear, and very little power of decision in her hands (though more than she first thought). Mary Pitt too was faced with real dilemmas, not least the risk of committing her fortune to a man with divided loyalties, and to coming between such a long-established brother-and-sister collaboration, all the more intense for being largely unexpressed.

Not surprisingly, Herschel’s first proposal was promptly turned down by Mary Pitt. The wealthy widow was perhaps not so vulnerable as she appeared. Herschel politely withdrew his offer, as Mrs Papendiek, all agog, soon learned. ‘Dr Herschel expressed his disappointment, but said that his [astronomical] pursuit he would not relinquish; that he must have a constant Assistant and that he had trained his Sister to be a most efficient one. She was indefatigable, and from her affection for him would make any sacrifice to promote his happiness.’65 Caroline was safe.

But only temporarily. After some months the delicate negotiations were reopened, and a different compromise was agreed upon. Mary Pitt as Mrs William Herschel would become undisputed mistress of both establishments, at The Grove and at Upton. She would keep her own servants in both houses, preside at William’s table in both, and oversee all his business accounts, including his scientific expenses (which of course she would be underwriting). Two of her maidservants would be kept at both houses, and finally, there would be a footman whose sole job was to take messages along the path between Upton and The Grove.

What was left for Caroline? She would remain at The Grove, but no longer as its mistress and housekeeper. She would move out permanently to the apartment above the stables, next to the observatory buildings. Here she would remain purely as William’s ‘astronomical assistant’, though she could continue as an astronomer in her own right with her sweeper telescopes on the flat roof.

Perhaps a greater blow to her pride was that Caroline would have no further control of the business accounts. In fact she would be offered a quarterly salary of £10, just like a regular employee. This was the same sum that William had once given her just to buy a dress for her singing performances. Caroline pointedly refused this financial proposal, though it is obvious that William would have much preferred her to accept, as no doubt it would have greatly eased his conscience.

But Caroline’s increasingly prickly sense of independence would not allow it. Indeed she later came to believe, or at least to claim, that she had arranged the royal salary precisely to avoid having to accept the fraternal one. ‘I refused my dear Brother’s proposal (at the time he resolved to enter the married state) of making me independent, and desired him to ask the King for a small salary to enable me to continue his assistant. £50 were granted to me, with which I was resolved to live without the assistance of my Brother.’ In fact of course the royal stipend had begun eighteen months before the marriage. Caroline would not feel able to accept her brother’s offer for another fifteen years.66

Whatever Herschel’s feelings for Mary Pitt, he was evidently uncertain about the whole arrangement, and was asking advice from the faithful William Watson as late as March 1788, a mere six weeks before the wedding. Watson ‘collected the general opinion’ of Herschel’s friends, and found that all were in favour of the union, ‘excepting some little fears with respect to Astronomy’. It was thought that Herschel might ‘relax somewhat’ the intensity of his night observations. Personally Watson thought this would be a good thing for his health-‘I fear your endeavours are too fatiguing, both to your mind and body’-and that it would ‘likewise turn out to the advantage of Science upon the whole’. No one apparently said a word about Caroline, unless she was included under the rubric of ‘Astronomy’.67

William Herschel and Mary Pitt were married on 8 May 1788, at the tiny parish church of Upton. Sir Joseph Banks rode down from London to be best man. In an inclusive gesture, Caroline Herschel was asked to be one of the two formal witnesses, and when William Watson volunteered to be the other one, Caroline gallantly agreed.68

Caroline’s last entry in her journal before the wedding is poignant in its determinedly matter-of-fact tone: ‘The observations on the Georgian satellites furnished a paper which was delivered to the Royal Society in May. And the 8th of that month being fixed on for my Brother’s marriage; it may easily be supposed that I must have been fully employed (besides minding the Heavens) to prepare everything as well as I could, against the time I was to give up the place of a Housekeeper which was the 8th of May, 1788.’69

There is no emotional outburst, no tears or recriminations. The only clue to the strength of Caroline’s feelings is the fact that she unconsciously repeats the date of William’s wedding in the same sentence, and suddenly invents that wonderfully imaginative phrase, ‘minding the Heavens’. It is such a tender and ironic description of her entire career: she is the housekeeper to the heavens. But she then seems to hurry it away-the career and the phrase-into a bracket. Caroline did eventually give one further indication of her feelings. It was an entirely silent one, yet was the most dramatic personal gesture she ever made. She completely destroyed her personal journals covering the whole of the next decade of her life. Her records do not begin again until October 1798.

The only person who may have glimpsed these journals before they were destroyed, or known something of their contents, was another woman, Caroline’s future editor Margaret Herschel, the wife of her nephew John. Though restrained by strong family loyalties, Margaret left one circumspect but highly sympathetic comment about the journals in print: ‘It is not to be supposed that a nature so strong and a heart so affectionate should accept the new state of things without much and bitter suffering. To resign the supreme place by her brother’s side which she had filled for sixteen years with such hearty devotion could not be otherwise than painful…One who could both feel and express herself so strongly was not likely to fall into her new place without some outward expression of what it cost her-tradition confirms the assumption-and it is easy to understand how this long significant silence is due to the light of later wisdom and calmer judgement, which counselled the destruction of all record of what was likely to be painful to survivors.’70

Over the years Caroline gave various quite different reasons for taking this extreme step. Mostly she passed it off by saying her journals were too dull to be of interest; or would not be understood; or else showed her lack of scientific achievement: ‘These books I thought it best to destroy; excepting some fragments which I some 4 or 5 years since sent to my Nephew as waste paper. For, in consequence of my employment at the Clocks and writing Desk, when my Brother was observing I had no other opportunity for looking out for Comets, but when he was absent from home, but this happened so seldom and my sweeps were so broken and unconnected that I could not bear the thoughts of their rising in judgement against me; and besides they contained nothing new but the discovery of 8 Comets and a few Nebs. & clusters of stars.’71

At the very least Caroline must have felt that a highly successful scientific partnership was being endangered, one that was now increasingly recognised in the international community of astronomers. But perhaps she felt more, much more. Caroline cannot have forgotten that ten years previously she had given up her own future as a concert singer, when she rejected the offer of a solo appointment after performing arias from Handel’s Messiah in 1778.72

It is hard to believe that she did not feel deeply hurt, and even in some obscure way emotionally rejected, by her brother. But it is difficult to gauge the exact nature of these deeper feelings, and she may not have analysed them too closely herself. More immediately evident was her sudden loss of social status within Herschel’s household. During this period in England, and even more so in Germany, previously dependent women-and notably unmarried younger sisters-would expect to be incorporated and remain happily within the newly married household. Caroline’s new quarters above the workshops at The Grove were an acceptable adaptation, but her loss of managerial and social responsibility must have felt humiliating. This eventually led her to take the extreme step of abandoning her apartment altogether, and taking rooms in Slough village with the wife of Herschel’s head workman, Mr Sprat.73

Yet outwardly things went on smoothly. Fanny Burney saw them all at a reception at Windsor later that summer, and thought the situation more amusing than tragic. ‘Dr Herschel was there, and accompanied them [the Miss Stowes] very sweetly on the violin; his new-married wife was with him and his sister. His wife seems good-natured; she was rich too! And astronomers are as able as other men to discern that gold can glitter as well as stars.’74

When the French astronomer Jérôme Lalande visited The Grove observatory in autumn 1788 he was evidently charmed by Herschel’s whole circle, and wrote to thank him with characteristic exuberance: ‘Je n’ai jamais passé de nuit plus agréable, sans en excepter celles de l’amour.’ Caroline may have considered that an odd turn of phrase, in the circumstances. Lalande also reported that he had had an audience with King George III, who announced that he was immensely proud of the Herschels and pointedly remarked, while walking on the terrace at Windsor, ‘that it was better to spend money on building telescopes than on killing men’.75

Caroline’s spirits were lifted a little just before Christmas 1788, when on 21 December she discovered her second comet. This time it was moving through the constellation of Lyra, the Harp or Lyre. Although it eventually turned out that it had already been spotted by Charles Messier, this discovery produced much more correspondence than the first, and letters of congratulation-mostly still addressed to William, but sometimes sent directly to her-came crowding in from all sides: from Alexander Aubert, Sir Harry Englefield, Nevil Maskelyne and Jérôme Lalande in Paris. Thereafter Lalande became one of her most faithful, witty and faintly flirtatious correspondents, happily conforming, as he himself pointed out, to the archetype of a Parisian professor. He sent ‘a thousand tender respects to la savante Miss, of whom I frequently speak with enthusiasm’. But then Lalande liked a little Gallic hyperbole, as he also addressed William on the envelope as: ‘Monsieur Herschel, le plus célèbre astronome de l’univers, Windsor, Angleterre’.76

Sir Harry Englefield, a stalwart of scientific committees, adopted a bluffer, but no less satisfactory manner, writing to Herschel on Christmas Day: ‘I beg you to make my compliments to Miss Herschel on her discovery. She will soon be the Great Comet Finder, and bear away the prize from Messier and Méchain.’77

The most significant, and perhaps unexpected, of these correspondents was the Astronomer Royal, Nevil Maskelyne. Writing directly to Caroline from Greenwich Observatory on 27 December, he began a regular and increasingly confidential exchange of letters. Although he wrote formally to congratulate her, he then added a long, teasing speculation about the interesting possibilities of a close physical encounter with her new comet. He wondered whether Caroline would ever be tempted to ride off on it into space. Any true astronomer like her, he suggested, would consider ‘without horror the thought of our being involved in its immense tail’. However, he hoped she would not be tempted: ‘I would not affirm there may not exist some astronomers so enthusiastic that they would not dislike to be whisked away from this low terrestrial spot into the higher regions of the heavens by the tail of a comet, and exchange our narrow uniform orbit for one vastly more extended and varied. But I hope you, dear Miss Caroline, for the benefit of terrestrial astronomy, will not think of taking such a flight, at least till your friends are ready to accompany you.’

Then he added, formally enough: ‘Mrs Maskelyne joins me in best compliments to yourself and Dr and Mrs Herschel.’ Yet these lighthearted urgings that Caroline should refrain from departing into outer space perhaps disguised Maskelyne’s deeper concern about her unsecured position at Slough. Maskelyne was a family man himself, with an only daughter, Margaret, whom he doted on. Perhaps he understood Caroline’s anxieties better than many in the scientific world.78


When the great forty-foot was at last put into operation in spring 1789, Herschel’s first discovery was Mimas, one of the tiny innermost moons of Saturn, with a diameter of only 250 miles. This was a remarkable piece of astronomical observation, and promised well for the powers of the new monster instrument. Mimas is dominated by a single huge crater, eighty miles across and six miles deep, which was much later photographed and named ‘Herschel’, but only after the Voyager flyby of 1980.

Herschel gave a detailed description of the way he managed the fortyfoot in a series of papers delivered to the Royal Society, illustrated by careful drawings.79 He also described Caroline’s wooden shed, situated some fifty feet beneath his own platform, equipped with masked candles, star atlases, warning bells and zone clocks.80

The completion of the telescope had finally been achieved with grants totalling £4,000 from King George III, an unprecedented amount for the sovereign to spend on a single scientific project of this kind. It was in fact exactly the same sum that the Royal Society had invested in 1768 in the entire scientific team (excluding Banks) for Cook’s first three-year expedition to the South Seas. Like King George’s Library (presented to the British Library by his son), the forty-foot telescope at Slough became one of the glories of his reign. It quickly became a tourist attraction, and was eventually featured in a popular Victorian magazine as one of ‘The Wonders of the World’, comparable to the Colossus of Rhodes.81

The doctor and writer Oliver Wendell Holmes included it in his tour of famous sites outside London. In his book The Poet at the Breakfast Table (1872) he described how he had previously seen an engraving of the great telescope in a child’s encyclopaedia back at home in America. So when he rode down the London-to-Bath turnpike road its huge outline reared up over the trees at Slough ‘like a reminiscence rather than a revelation’. It seemed a strange, unworldly shape. ‘It was a mighty bewilderment of slanted masts, spars and ladders and ropes, from the midst of which a vast tube, looking as if it might be a piece of ordinance such as the revolted Angels battered the wall of Heaven with, according to Milton, lifted its mighty muzzle defiantly towards the sky.’82

But Herschel found the huge barrel of the forty-foot telescope unexpectedly difficult to prepare and manoeuvre in anything but perfect weather conditions. The vast surface of the metal speculum was far more susceptible to misting, oxidisation and distortion than those in his smaller telescopes. The one-ton mirrors were also alarmingly cumbersome to change, and Caroline remembered how both William and Alexander ‘had many hair-breadth escapes from being crushed’ when taking them in and out of the base of the telescope, even with the help of their workmen.83 By the end of 1789 it was evident that the forty-foot was going to take years, rather than months, to prove its worth.

Through the 1790s Herschel had an ever-increasing sense that he must justify his project, and that the forty-foot was becoming something of a liability. He recorded that in the five years between 1788 and 1793 he managed only seventeen nights of ideal observations, a disastrous statistic.84 Ironically, the elegant twenty-foot (much preferred by Caroline) continued to be better for deep-space stellar observations, being both more manoeuvrable and more stable. After Mimas, Herschel’s best discoveries with the forty-foot remained inside the solar system: he added two new moons to Saturn, five already being known. The forty-foot fared much better as a national scientific showpiece, attracting a large number of European visitors, among them the head of the Paris Observatory and astronomy professors from Berlin, Cracow and Moscow.85

The annual need to repolish the huge three-foot mirrors became a growing burden, and in September 1807 Herschel was nearly killed when the one-ton speculum slipped from its harness while being removed from the tube. Many years later, in 1815, he quietly published a paper entitled ‘A Series of Observations on the Georgian Planet’, in which he admitted the insoluble problems of condensation, manoeuvring and servicing which the forty-foot had brought him.86

Yet Herschel’s theoretical work now blossomed in an extraordinary and daring way. In 1789, the year of the Fall of the Bastille, he published a paper carefully dated ‘Slough near Windsor May 1 1789’, and gave it the deliberately anodyne title ‘Catalogue of Second Thousand Nebulae with Remarks on the Construction of the Heavens’. This developed his revolutionary 1785 paper ‘On the Construction of the Heavens’, and extended it with a striking analogy between the botanical cycle as observed on earth, and an organic or ‘vegetative’ cycle which appeared to be operating throughout the entire universe.

The paper completely overturned any residual idea of a stable, overarching, temple-like universe, created once and for all by the great Celestial Architect and decoratively ‘fretted with golden fire’, as Hamlet once mentioned. On the contrary, Herschel suggested, the whole universe was subject to enormous fluid movements and changes, over vast periods of time, and these could be observed in the degree of ‘compression’ or ‘condensation’ of nebulae, and the ‘comparative variety’ of size and structure of deep-space star clusters. Herschel’s crucial observation was that some galaxies were evidently older, and more evolved, than others. ‘We are enabled to judge of the relative age, maturity, or climax, of a sidereal system, from the disposition of its component parts.’ Nebulae and star clusters were in effect like ‘species of plants’, at various stages of growth and decay.

He explained this in his usual quiet, patient manner. ‘Youth and age are comparative expressions; and an oak of a certain age may be called young, while a contemporary shrub is already on the verge of its decay.’ The fundamental force at work was gravity, gradually over time compressing nebulous gas into huge, bright galactic systems, and eventually condensing into individual stars, ‘So that, for instance, a cluster or nebula which is very gradually more compressed and bright towards the middle, may be in the perfection of its growth.’ While another type of cluster, showing a more equal compression or distribution of individual stars, might be looked upon as ‘very aged, and drawing towards a period of change, or dissolution’.

This method of viewing the galaxies (’to continue the simile I have borrowed from the vegetable kingdom’) presented the entire universe in a new kind of light, with the most radical implications. ‘The heavens are now seen to resemble a luxuriant garden which contains the greatest variety of productions, in different flourishing beds…and we can extend the range of our experience [of them] to an immense duration.’ In a garden we may live ‘successively to witness the germination, blooming, foliage, fecundity, fading, withering and corruption of a plant’. Just so, the universe presented ‘a vast number of specimens, selected from every stage through which the plant passes in the course of its existence’, but brought ‘at once to our eyes’, and viewed at one particular moment from the earth.87

In this paper, astronomy changed decisively from a mathematical science concerned primarily (for practical purposes) with navigation, to a cosmological science concerned with the evolution of the stars and the origins of the universe. The implications were slowly absorbed, most notably by the French astronomer Pierre Laplace, who published his first paper on what he called ‘the nebular hypothesis’ in 1796.88 But the revolutionary analogy, which made astronomy a life science with huge philosophical implications, was soon to be celebrated by Erasmus Darwin in the final book of The Botanic Garden (1791).

There were other, more personal forms of evolution. The year 1792 saw a decisive change in Herschel’s family life. At the age of fifty-three he rejoiced in the birth of his first and only child, his son John. The regime at The Grove became steadily more domestic and sociable. Annual summer holidays, previously unheard of, began, with trips to Cornwall, the south coast and Scotland. Although Caroline rarely participated in these, the arrival of this little child would eventually affect her life too, as much even as her comets.

For the moment, though lonely and isolated, Caroline was doing the best observational work of her career. Pierre Méchain wrote admiringly to William on 25 October 1789, ‘her renown will be held in honour throughout the ages’.89 She continued to find new comets. In 1790 she found her third and fourth, in December 1791 a fifth, and a sixth in October 1793. She herself reported this sixth comet directly to the Royal Society, and her reputation continued to grow fast in astronomical circles. Articles appeared about her work in a number of women’s journals, and a faintly scurrilous cartoon was published entitled ‘The Female Philosopher Smelling out a Comet’. The comet is depicted as a small child hurtling through the night sky, driven by a fart, while the female astronomer, peering through her telescope and clutching her hands in delight, remarks enthusiastically on the ‘strong sulpherous scent’ of the comet’s coma. But the depiction of Caroline, with her characteristic mass of curly hair, is surprisingly handsome.90

Her friendship with Maskelyne, the Astronomer Royal, continued to deepen, and he invited her to stay with him and his family at Greenwich, though she did not immediately accept. With his approval she had begun an updated Star Catalogue, which would eventually correct and supersede Flamsteed’s, and receive the signal honour of being published at the Royal Society’s own expense.

In November 1795 she ‘shared’ a comet with the German astronomer Johann Encke. Then in August 1797 she found her seventh. She was so excited by this last one that she did something unprecedented for her. After only one hour’s sleep, she had a horse saddled for her in Slough, and rode the twenty-odd miles into London at dawn, then crossed the Thames bridge, and appeared at Maskelyne’s observatory at Greenwich for a late breakfast. She gave him a precise memorandum of the comet’s position, which he confirmed that night.

At Maskelyne’s urging, Caroline wrote to Sir Joseph Banks in Soho Square pointing out that it was a truly historic day, since she had never previously ridden more than two miles beyond Slough. This letter, dated 17 August 1797 from Greenwich, has a light-headed, almost flirtatious tone, which was again quite new for Caroline.

Sir-This is not a letter from an astronomer to the President of the Royal Society announcing a comet, but only a few lines from Caroline Herschel to a friend of her brother’s, by way of apology for not sending intelligence of that kind immediately where it was due…Dr Maskelyne was so kind as to take some pains to persuade me to go this morning ‘to pay my respects to Sir Joseph’, but I thought a woman who knows so little of the world ought not to aim at such an honour; but go home, where she ought to be, as soon as possible.91

It would appear that Caroline stayed on with Maskelyne’s family for at least two days. This gesture of independence was shortly followed by a radical change in her lodging arrangements. In October 1797 she moved out of her apartment at The Grove, and into lodgings up the road in Slough village. She also began a new ‘day book’, in which the first entry read: ‘1797, in October I went to lodge with one of my brother’s workmen (Sprat), whose wife was to attend on me. My telescopes on the roof, to which I was to have occasional access, as also to the room with the sweeping and observing apparatus, remained in its former order [at The Grove], where I most days spent some hours in preparing work to go on with at my lodging.’92

The exact significance of this move remains puzzling. To take lodgings with her brother’s chief workman clearly sounds like a gesture of defiance against Mary Herschel. The reference to being allowed only ‘occasional access’ to her telescopes almost suggests that Caroline was being excluded from The Grove against her will. Yet she continued to work successfully on her enlarged and corrected edition of the Star Catalogue, which was completed and submitted to the Royal Society the following spring, on 8 March 1798. Its subsequent adoption and publication by the Society was a recognition of outstanding professional merit. Significantly, this was partly achieved through Nevil Maskelyne’s good offices.93

Caroline wrote to Maskelyne, thanking him for all his support, in terms that begin conventionally enough. ‘I thought the pains it had cost me were, and would be, sufficiently rewarded in the use it had already been, and might be in the future, to my brother. But your having thought it worthy of the press has flattered my vanity not a little.’ However, she continued in a rather more provoking vein. ‘You see, Sir, I do own myself to be vain, because I would not wish to be singular; and was there ever a woman without vanity?…Or a man either? Only with this difference, that among gentlemen the commodity is generally styled ambition.’ She leaves the implication of that-does she have any particular gentleman in mind?-hanging in the air, and turns to publication details of her Star Catalogue.

She ends her letter on a more intimate note. ‘Many times do I think with pleasure and comfort on the friendly invitation Mrs Maskelyne and yourself have given me to spend a few days at Greenwich. I hope yet to have that pleasure next spring or summer. This last has passed away, and I never thought myself well or in spirits enough to venture from home. If the heavens had befriended me, and afforded us a comet, I might, under its convoy, perhaps have ventured upon an emigration’. She had not forgotten Maskelyne’s original joke about her flying away on the comet of 1788; and perhaps she was also thinking of her first thrilling emigration from Germany with William long ago in 1772.94

Caroline’s move to lodgings in Slough can be seen as an assertion of professional independence, and even perhaps a recognition of rivalry with her brother. Her day book for the following summer suggests that she had established a steady but solitary routine. In July 1799 she entered: ‘My brother went with his family to Bath and Dawlish. I went daily to the Observatory and work-rooms to work, and returned home to my meals, and at night, except in fine weather, I spent some hours on the roof, and was fetched home by Sprat.’95 In fine weather, of course, she stayed on the roof all night.

But the move must also have reflected an increasing sense of loneliness. She later wrote poignantly about her feelings of solitude and isolation. Such a revelation is extremely rare in her Memoir, and it almost seems to have taken Caroline herself by surprise. In the second, revised version of the Memoir she writes about her brother Alexander’s unhappy love affairs, before he married. Unexpectedly, she adds a footnote: ‘…And I may here remark that I still was and remained almost throughout my long life without a Friend to whom I could have turned for comfort and advice when I was surrounded by trouble and difficulties. This was perhaps in consequence of my very dependent situation, for I never was allowed to form any acquaintance with any other but such as were agreeable to my eldest brother.’96 This is a surprisingly bitter remark, given Caroline’s correspondence with Aubert and Lalande, and above all her blossoming friendship with the Maskelyne family. Indeed, in summer 1799 she went to stay with them in Greenwich for about a fortnight.

When Faujas de Saint-Fond, the science writer and balloon enthusiast, on a long scientific tour of England and Scotland, visited The Grove at this time, he was encouraged to watch Herschel and Caroline working together on night observations. He saw nothing amiss, but on the contrary admired the constancy and ‘delightful accord’ of the brother-sister team working so closely together on ‘this sublime but abstruse science’. Caroline explained to him the unique system of communications between William, high up on the observation platform, and herself below at her desk with its shrouded candlelight, zone clocks and star atlases. To the original method of shouted question and answer-‘Brother, search near the star Gamma Orion’-they had now added a system of coded rope-pulls, hand signals and bells. Later they would add the flexible speaking-tube. Perhaps this was symbolic of their changing relationship.97

Herschel himself at last began to mention ‘my sister Miss Herschel’, or ‘my indefatigable assistant, Caroline Herschel’, more regularly in his Royal Society papers. She appears in his historic ‘The Description of a Forty Foot Reflecting Telescope’ (1795), and again in ‘A Third Catalogue of the Comparative Brightness of Stars’ (1797). But once again his own mind seems to have been elsewhere.


In 1791 Herschel had published a highly significant paper with the Royal Society, ‘On Nebulae Stars, Properly So-called’. For the first time he had observed an individual star with what he called ‘true nebulosity’, that is surrounded by a shining cloud of diffuse gas, even though it was already formed as a star. This observation caused him some dismay, because he had previously assumed that gas clouds were simply star clusters too far beyond our galaxy to be ‘resolved’ by his telescopes (even the forty-foot) into individual stars. The existence of true ‘nebulae stars’ suggested that perhaps most-or even all-gas clouds without resolvable stars were not distant star clusters after all, but simply nebulae much nearer than he had previously thought. ‘Perhaps it has been too hastily surmised that all milky nebulosity, of which there is so much in the heavens, is owing to starlight only.’98 He began to question his own extra-galactic theories, and wondered if all nebulae actually existed within the Milky Way. It therefore seemed possible-though he never stated this-that finally there were no other ‘island universes’ outside ours. It was a decisive retreat from his most radical thinking about the size and origin of the cosmos.

This theoretical retreat may have partly reflected a growing fear of radical science in England. When Erasmus Darwin published his long scientific poem in two parts, The Botanic Garden in 1791, he soon found that he had caused controversy by adopting Herschel’s galactic theories without caution or reservations. Drawing on Herschel’s earlier two papers on the ‘Construction of the Heavens’ (1785 and 1789), but ignoring the revisionist ‘On Nebulae Stars’ (1791), Darwin praised the great astronomer’s ‘piercing sight’ into the cosmos, and his liberating new concept of an evolving universe, with distant nebulae growing and expanding like plants.

In a bravura passage, Darwin also considers Herschel’s disturbing suggestion that the entire cosmos may eventually wither back into ‘one dark centre’. This implies that the universe not only had a beginning, but will have a physically destructive end, a ‘Big Crunch’. There are hints here too of Milton’s vision of the falling rebel angels dropping out of the firmament in Book I of Herschel’s favourite, Paradise Lost. This itself had possible political overtones for a reader in the 1790s, especially after the execution of Louis XVI in 1792.

So, late descried by Herschel’s piercing sight,

Hang the bright squadrons of the twinkling night…

Flowers of the sky! Ye to age must yield,

Frail as your silver sisters of the field!

Star after star from Heaven’s high arch shall rush,

Sun sink on suns, and systems systems crush,

Headlong, extinct, to one dark centre fall,

And death and night and chaos mingle all!99

Darwin’s note to this section calmly remarks: ‘From the vacant spaces in some parts of the heavens, and the correspondent clusters of stars in their vicinity, Mr Herschel concludes that the nebulae or constellations of fixed stars are approaching each other, and must finally coalesce in one mass. Philosophical Transactions Vol. LXXV.’ He adds however the consoling thought that a new universe may arise, phoenix-like, from the collapsed one (which might please contemporary proponents of multiverses). ‘The story of the phoenix rising from its own ashes with a twinkling star upon its head, seems to have been an ancient hyroglyphic emblem of the destruction and resuscitation of all things.’100

Atheistical ideas were growing among Continental astronomers, and with the declaration of war against France these became even more suspect in Britain. In 1792 Herschel’s great friend Jérôme Lalande published a third, enlarged edition of his authoritative Traité d’Astronomie, in three volumes, which expressed increasingly sceptical views. Eight years later he wrote an approving Preface to the Dictionnaire des Athées (1800). His final view before his death in 1807 was delivered with a flourish: ‘I have searched through the heavens, and nowhere have I found a trace of God.’101

Pierre Laplace, another avowed atheist, now drew on Herschel’s ‘nebulae hypothesis’ of star formation, and applied it to the formation of the solar system. He expanded this in the first volume of his classic Mécanique Céleste (1799). In effect he reasoned that the sun had slowly condensed out of a nebulous cloud of stardust, and then spun off our entire planetary system, just as in a thousand other star systems. There was no special act of Creation. In this way he was able to give a purely materialist account of the creation of the earth, the moon and all the planets. No divine intervention or Genesis was required, nor was it visible anywhere else in the universe.102 Years later, Herschel’s son John would argue that the nebula theory did not apply to the solar system, which was a special case, a ‘singularity’.

Laplace’s cool confidence in avowing atheistical sentiments was legendary. The story was told that after Napoleon had inspected a copy of Laplace’s Système du Monde, he challenged the astronomer about his beliefs. ‘Monsieur Laplace! Newton has frequently spoken of God in his book. I have already gone over yours, and I have not found His name mentioned a single time.’ To this Laplace made the magnificent and disdainful reply: ‘Citizen First Consul, I have no need of that hypothesis.103

Herschel however was still interested in extraterrestrial life, and in 1795 published one of his most extraordinary papers, ‘On the Nature and Construction of the Sun’, with the Royal Society, suggesting that the sun had a cool, solid interior and was inhabited by intelligent beings. He reiterated his original claim that the moon was inhabited, and added that by analogy ‘numberless globes’ among the stars must support ‘living creatures’. However, he disapproved of God-hunting within the galaxy, and attacked the ‘fanciful poets’ who had suggested that the sun was ‘a fit place for the punishment of the wicked’, viz. a fiery hell constructed for divine vengeance.104

Unlike Joseph Priestley, whose library was burnt down by a Birmingham mob in 1794, Herschel managed to avoid any public reputation for heterodox opinions. Visits to his observatory were regarded as uplifting, even religious experiences. Joseph Haydn claimed that his visit to Herschel at Slough in 1798 had helped him compose his oratorio The Creation. No scepticism undermines Haydn’s joyful celebration of a universe abounding in benevolence, and still safely in the hands of the omnipotent God of Genesis. The dramatic moment of declaration occurs when Chaos, suggested by the key of C-minor, gives way to D-flat major, then to C-major, with the thunderous Scriptural proclamation, ‘Let there be light!’105

In 1800 Herschel’s continued interest in the sun led him to return to the problem of the prismatic distribution of solar light. While making direct observations of the sun (an extremely hazardous operation), he noticed that there were some indications of heat just outside the visible spectrum. In a series of experiments with thermometers mounted along a marked bar, he succeeded in measuring raised temperatures above the visible spectrum of solar light. Though he did not name it, he had discovered the presence of infra-red light. Once again he had broken a boundary of conventional knowledge.

News of this discovery spread rapidly through the scientific community. Henry Cavendish came over from Cambridge to see the experiment, and Benjamin Thompson, a founding member of the newly formed Royal Institution, came down from London. Sir Joseph Banks, delighted to offset Herschel’s slow progress on the forty-foot, wrote that he considered that this would ultimately prove a more important discovery even than that of Uranus.106

On 3 July 1800 a young Cornishman named Humphry Davy wrote excitedly to his friend Davies Giddy: ‘You have undoubtedly heard of Herschel’s discovery concerning the production of heat by invisible rays emitted from the sun. By placing one thermometer within the red rays, separated by a prism, and another beyond them, he found the temperature of the outside thermometer raised by more than that of the inside.’107 This marked a decisive advance on Newton’s famous optical experiments with the prism, and implied a hitherto wholly unsuspected power in nature. It would also eventually lead to a decisive breakthrough in stellar astronomy in the twentieth century.

Herschel’s public reputation as an astronomer steadily increased. In September 1799 he had been secretly commissioned by the War Office to provide a hundred-guinea spy telescope to be mounted on the walls of Walmer Castle, on the extreme south-east coastal point of Kent, to give early warning of a possible French invasion fleet. It was thought that the telescope could also spot any signs of the suspected aerial invasion by troop-carrying Montgolfiers.108

In 1801 Herschel was included in the first volume of the new biographical series of Public Characters, alongside Nelson, Pitt, Charles James Fox, Erasmus Darwin, the artists James Northcote and John Opie, Priestley, the anthropologist Lord Monboddo, the actress Sarah Siddons and the Bishop of Llandaff (who was appointed Professor of Chemistry at Edinburgh and promptly blew up his entire laboratory). Besides astronomy, Herschel’s entry remarks on his gift for languages, his interest in metaphysics and (perhaps rather out of date) his habit of breaking off a concert to run outside and observe the stars. It also mentions in passing the remarkable talents of his sister Caroline.109

In July 1802 Herschel and his wife undertook a visit to Paris, during the short-lived Peace of Amiens. They were greeted as guests of honour by the Institut de France, and chaperoned by their old friend Lalande. They were introduced to the great mathematician Laplace, and were granted an audience with Napoleon, an interview that was chiefly memorable for the ice creams they were given to eat. They initially met the future Emperor in the garden of the Malmaison Palace, where he was supervising the irrigation of some newly planted flowerbeds. He was small and animated, appearing to be expertly informed on whatever subject arose (for example the construction of canals). Then, making a display of extreme informality, Napoleon bustled the party through some french windows into a drawing room, and flung himself down upon an upholstered chair. Herschel pointedly refused to sit in his presence, but carefully answered ‘a few questions on Astronomy and the construction of the Heavens’. After further rather stilted conversation, Napoleon became sententious and announced to the assembled company that astronomy ‘gave proof of an Almighty Wisdom’. Given the pronounced atheistical views of Laplace, his Chief Scientific Advisor (who was also present), Herschel thought Napoleon was being hypocritical, and actually believed nothing of the sort.

This rather froze the atmosphere, until the conversation turned to English racehorses (admirable, thought Napoleon), the English police system (slack), and English newspapers (unlicensed and amazingly out-spoken). Napoleon then had the delicious ice creams served, in several different fruit flavours, while he observed that it was singularly hot, the temperature in the Malmaison garden being precisely 38 degrees in the shade. Herschel noted that the First Consul pointedly used the new centigrade system, and made the quick mental calculation that this meant it was 100.4 degrees Fahrenheit.

Suddenly Napoleon rose from his chair, made a brisk farewell, and without more ado swept out through a side door, pursued by several anxious aides and officers. Herschel only relaxed when he was returning to their hotel in a carriage with Laplace, discussing the rotations of double stars. He suggested that three stars might orbit round a common centre of gravity; but Laplace with an ironic smile contended that as many as six was possible, if not advisable. The First Consul crowned himself sole Emperor four years later.110

During this diplomatic episode little John, now aged ten, was left in the care of an elderly Polish Count, who showed him the animals in the Jardin des Plantes, which looked as lonely as himself. Aunt Caroline did not go on this Paris trip, but was left behind at the observatory to look after the telescopes and the visitors. She must particularly have missed meeting Lalande, who always included her in his letters, and would still send ‘a thousand tender respects to la savante Miss’.111 

Yet the trip was to prove important to her in one way. On the family’s return from Paris to ‘dear old England’, the excitement of reunion began a new bond with her nephew John. The little boy had fallen ill on the return journey at Ramsgate, and it was Caroline who nursed him back to health, and listened to his tales of Continental adventures, and how he had sadly missed out on those delicious French ice creams. She had always felt tenderly towards the child, and after her move out to Slough in 1799 she noted: ‘my dear nephew was only in his sixth year when I came to be detached from the family, but this did not hinder John and I from remaining the most affectionate friends’. Small herself, she loved sitting beside him on the carpet, ‘listening to his prattle’. From the age of eight he would bring scraps of poetry to her, written ‘in a most shocking handwriting’.112

The solitary, rather solemn little boy came to adore his aunt, and it was she, as much as his father, who inspired in him an early passion for science and astronomy. The shy and diminutive Caroline was able to play with him, and enter deeply into his childhood world, in a way that his father, now about to enter his sixties, was unable, or simply too distracted, to do. She arranged games for him in the garden, and messy experiments on the floor of her lodgings. ‘Many a half or whole holiday he was allowed to spend with me…dedicated to making experiments in chemistry, where generally all boxes, tops of tea-cannisters, pepper-boxes, teacups etc served for the necessary vessels, and the sand-tub furnished the matter to be analysed. I only had to take care to exclude water, which would have produced havoc on my carpet.’113

When John was found climbing in the scaffolding of the forty-foot, or secretly having tea with the workmen, or cutting geometrical shapes in the panelling of the drawing room with a chisel, it was Caroline who always leaped to his defence.114 It was also she who gave him several workshop tools for his birthdays, including the small wood-plane, proudly incised with the name ‘John’ on the handle, which he kept for the rest of his life.115

When John was sent to Eton at the age of eight, it was Caroline who saw how unhappy he was there, and tried to persuade William and Mary to choose a different mode of education from John’s extrovert stepbrother Paul, who had flourished at the school. Mary was reluctant to make the change until she saw John knocked down in a boxing match with an older boy, after which she summarily withdrew him and employed a private tutor, much to Caroline’s delight.116 A portrait of John at this time shows a small, delicate, wide-eyed boy, wistfully holding a wooden hoop, with the towers of Windsor Castle and Eton distantly on the horizon.

In an extraordinary way the relationship between Caroline and her young nephew began to heal whatever suppressed strains and rivalries there were within the Herschel household. Caroline and Mary were increasingly united in their concern for John’s welfare, while Caroline knew how to interpret emotionally-as well as scientifically-between father and son. Later, this mentoring relationship would take on unusual importance.


As he grew older, Herschel was becoming a remoter figure in the household. His mind was ranging through the universe. His later papers for the Royal Society had begun to show an increasing awareness of the philosophical significance of astronomy. This was something urged upon him by his old supporter William Watson, who looked forward to conversations ‘on Kant’s metaphysics’, and wished to know how far Herschel agreed with the ‘ground and sources’ of Kant’s philosophy of knowledge.117

Already in a paper of 1802 Herschel considered the idea that ‘deep space’ must also imply ‘deep time’. He wrote in his Preface: ‘A telescope with a power of penetrating into space, like my 40 foot one, has also, as it may be called, a power of penetrating into time past…[from a remote nebula] the rays of light which convey its image to the eye, must have been more than 19 hundred and 10 thousand-that is-almost two million years on their way.’ The universe was therefore almost unimaginably older than people had previously thought. This idea of deep time was one which required a great deal of explanation to the layman.118

Other papers were unsettling in different ways. ‘Observations tending to investigate the Nature of the Sun’ (1801) proposed that sun-spot activity could be related to the price of wheat, because it affected the mildness or severity of terrestrial seasons, and hence the fertility of global harvests. Thus the sun, rather than the stars or comets, could bring about political revolutions on earth.119 Another paper, ‘On the Proper Motion of the Solar System’, showed that not only did the planets revolve round the sun, but that the entire solar system itself moved through stellar space, orbiting round an unidentified centre in the Milky Way, which was itself moving relative to other galaxies.120

Herschel continued to reach carefully towards the idea of an evolving universe, a concept as radical in its eventual implications as Erasmus Darwin’s notion of evolution within plants and animals. In a late paper published in 1811, ‘Astronomical Observations relating to the Construction of the Heavens’, Herschel further developed the idea, already explored in ‘On the Construction of the Heavens’(1785) and ‘Catalogue of Second Thousand Nebulae with Remarks on the Construction of the Heavens’ (1789), that all nebulae and large star clusters were at particular points in their sidereal life-cycles, which could be visually identified and catalogued almost in a Linnaean manner. Their characteristic shapes suggested distinct moments of youth, maturing and ageing.

Herschel accompanied this paper with numerous drawings of the nebulae he had observed over thirty years in these different phases: some globular, some spiral, some flattened, some mere blots of incoherent light or chaotic milky spillages. Many, such as the beautiful and characteristic whorl of Andromeda, are now instantly recognisable because of the modern Hubble photographs. These shapes, Herschel argued, were not different because they had been created differently, like different species. They were different simply because their stages of development in what he called ‘sidereal time’ (meaning stellar time) had reached different points. He was suggesting the inescapable idea of evolutionary youth and age in the universe.121

This presentation was radically different from anything seen in any previous astronomical papers anywhere in Europe, except in the broadest philosophical speculations of Kant, the French cosmologist the Comte de Buffon, or Laplace. It presented the universe as a living, growing, organic entity, with all nebulae belonging to one enormous extended family: ‘There is not so much difference between them, if I may use the comparison, as there would be in an annual description of the human figure, were it given from the birth of a child till he comes to be a man in his prime.’ This comparison is an intriguing premonition of ‘time-lapse’ photography, now one of the most powerful illustrative tools of modern natural history.122

Above all, Herschel’s studies of nebulae and the general ‘construction of the Heavens’ demonstrated how Copernicus’ rejection of an earthcentred universe had long been superseded by contemporary science. Not only a sun-centred galaxy, but even a cosmos centred on the Milky Way itself, had to be rejected. This implied an enormous psychological, even spiritual, shift in outlook: seeing our entire solar system as something very small, very far out, on the very edge of the edge of things. As Herschel had written: ‘We inhabit the planet of a star belonging to a Compound Nebula [the Milky Way] of the third form…‘123 

Over the next decade Herschel’s work began to be widely known by the younger generation of Romantic writers. Byron visited him at Slough in 1811, and viewed the stars through his telescope, which gave him an alarmingly religious experience: ‘The Night is also a religious concern; and even more so, when I viewed the Moon and Stars through Herschel’s telescope, and saw that they were worlds.124 Later Byron defended himself against accusations of atheism. ‘I did not expect that, because I doubted the immortality of Man, I could be charged with denying the existence of a God. It was the comparative insignificance of ourselves and our world, when placed in competition with the mighty whole, of which it is an atom, that first led me to imagine that our pretensions to eternity might be…over-rated.125

John Bonnycastle’s highly successful Introduction to Astronomy in Letters to his Pupil was reissued in an enlarged edition in 1811, with an expanded chapter dedicated to Herschel’s work and other ‘new discoveries’. This was the edition given to John Keats at his Enfield school, and later taken to his lodgings near Guy’s Hospital. Bonnycastle continued to include passages of poetry with his scientific explanations, and his work encouraged reflection on the imaginative as much as the philosophical impact of the new astronomy. In theological matters, however, Bonnycastle remained strictly orthodox.

Bonnycastle became apologetic about including poetry, too. In the Preface to his 1811 edition he warned his readers: ‘The frequent allusions to the Poets, and the various quotations interspersed throughout the work, were intended as an agreeable relief to minds accustomed to the regular deduction of facts, by mathematical reasoning…Poetical descriptions, though they may not be strictly conformable to the rigid principles of the Science they are meant to elucidate, generally leave a stronger impression on the mind, and are far more captivating than simple unadorned language.’126

Keats wrote his sonnet ‘On First Looking into Chapman’s Homer’ very early one autumn morning in October 1816. It celebrates a deeply Romantic idea of exploration and discovery. Without actually naming Herschel, it picks out the finding of Uranus, thirty-five years before, as one of the defining moments of the age. Although combining many sources of inspiration (it is possible that Keats may have attended Charles Babbage’s 1815 ‘Lectures on Astronomy’ at the Royal Institution), the poem itself was written in less than four hours.

Keats was twenty, and attending a full-time medical course at Guy’s Hospital. He had stayed out all night with his friend and mentor Charles Cowden Clarke at his house in Clerkenwell, drinking and discussing poetry. Clarke had acquired an old 1616 folio edition of Chapman’s verse translation of Homer’s Iliad, and they had taken turns to recite passages aloud. At particular passages Keats ‘sometimes shouted’ with delight. A favourite was the gloriously extended simile of shining light from Book Five. This compares the golden glow of the Greek warrior Diomed’s helmet to the glow of the planet Jupiter rising above the sea in autumn.

Like rich Autumnus’ golden lampe, whose brightness men admire, Past all the other host of Starres, when with his cheerful face, Fresh washt in lofty Ocean waves, he doth his Skies enchase.

With such images in his head, Keats left Clerkenwell at 6 a.m., shortly before autumn sunrise. The stars were still out as he crossed London Bridge making for his student lodgings at 8 Dean Street, Southwark, near Guy’s. He noticed the planet Jupiter, very bright, setting over the Thames. The moment he got to his lodgings, he sat down and began to write, starting with the inspired line, ‘Much have I travelled in the Realms of Gold…’. This perfectly introduced two linked ideas, of thrilling exploration and gleaming brightness, which orchestrate the whole poem.

Keats wrote so quickly that he was able to send a clean copy of the poem straight round to Cowden Clarke that same morning. Clarke remembered opening it at his breakfast table in Clerkenwell by 10 a.m. (a credit also to the postal system). He noticed the historical error-it was Balboa, not Cortez, who reached the Pacific-but was thrilled by the beauty and originality of the sonnet. Among other things, Keats had combined science and poetry in a new and intensely exciting way.127

Keats likens his own discovery of Homer’s poetry to the experience of the great astronomer and the great explorer finding new worlds.

…Then felt I like some watcher of the skies

When a new planet swims into his ken;

Or like stout Cortez when with wond’ring eyes

He stared at the Pacific-and all his men

Looked at each other with a wild surmise-

Silent upon a peak in Darien.

Both comparisons turn on moments of physical vision-watching, staring, looking with ‘wondering eyes’. (This was the original manuscript reading, although Keats later changed it to the more conventional ‘eagle eyes’.) Physical vision-one might say scientific vision-brings about a metaphysical shift in the observer’s view of reality as a whole. The geography of the earth, or the structure of the solar system, are in an instant utterly changed, and forever. The explorer, the scientific observer, the literary reader, experience the Sublime: a moment of revelation into the idea of the unbounded, the infinite.

In the case of Herschel’s sighting of Uranus, Keats’s word ‘swims’ is brilliantly evocative, because of its sense of new life and movement. The planet is like some unknown, luminous creature being born out of a mysterious ocean of stars. Keats may also have realised that convection currents in the atmosphere, or in the tube of the telescope itself, can give objects the appearance of being seen through a rippling water surface.128

Keats’s vivid idea of the Eureka moment of instant, astonished recognition celebrates the Romantic notion of scientific discovery. It is appropriate that this is expressed in the oddly anachronistic phrase ‘into his ken’ (grasp, knowledge), even though it may also be there for the rhyme. The efforts of Maskelyne, Messier and Lexell certainly took weeks, if not months, to confirm the identification of Herschel’s ‘comet’ in 1781. Yet it is also true that Herschel too, despite the evidence of his own Observation Journal, gradually convinced himself that precisely such a moment of instant, sublime discovery had occurred in the garden at New King Street. Herschel in the end may have remembered that night exactly as Keats imagined it.129


Journalists began to assess the current scientific views of such phenomena, ranging from the ‘deep time’ geological theories of James Hutton to the ‘deep space’ nebula theories of Herschel. An essayist in the Monthly Review for April 1816 noted archly that there was ‘a studious avoidance of any reference to God’ in any of these brave new theories. He presented them with a certain scepticism. ‘A long dissertation is allotted to the Huttonian Theory of the Earth; but all these speculations, we suppose, must now give way to the “discovery” of Dr Herschel, that planets began their being in the form of nebulous matter, and consist at first of a vast egg of gas!130

Meanwhile Herschel was quietly publishing more extraordinary late papers of cosmological speculation, notably ‘Astronomical Observations Relating to the Sidereal Part of the Heavens and the Connection with the Nebular Part: Arranged for the Purpose of a Central Examination’, a characteristically low-key title for a dramatic paper, dated 24 February 1814.131 Its final section was headed ‘The Breaking Up of the Milky Way’. In it he proposed that there was ‘a clustering power’ observable in many nebulae, that was producing a ‘progressive approaching’ within each star group. ‘We may be certain that from mere clustering stars they will be gradually compressed through successive stages of accumulation-till they come to what may be called the ripening period of the globular, and total insulation.’ So, as each star group was increasingly contracting in on itself, it would also be moving away from all the others into a state of greater and greater cosmic isolation.

From these vast movements within the observable universe, Herschel concluded that as some galaxies were being born, others were withering and dying. He had previously touched on this general idea. But he now put forward the apocalyptic proposition that our own galaxy was on the wane, and that there would inevitably be ‘a gradual dissolution of the Milky Way’. The progress of this observable dissolution would provide ‘a kind of chronometer that may be used to measure the time of its past and future existence’.

At all events, it was clear that the Milky Way ‘cannot last forever’; and equally that ‘its past duration cannot be admitted to be infinite’. It followed that neither the earth, nor even the solar system, was a separate creation, but merely an infinitesimal part of a galactic evolution. Our galaxy had a physical beginning, and would have a physical conclusion. Our solar system, our planet, and hence our whole civilisation would have an ultimate and unavoidable end.132

In 1817 Thomas Chalmers would publish his best-selling Discourses on Astronomy. He reflected on the atheistical implications of Herschel’s new cosmology, piously attempted to re-establish God’s role in the creation, but also raised intriguing questions about extraterrestrial life in the further planets of the solar system, and beyond. The book touched a public nerve, and sold 20,000 copies in its first year, although it was sceptically reviewed by William Hazlitt, one of his rare forays into the physical sciences. But the idea of a dramatically enlarged universe, which surely contained other civilisations apart from our own, was widely accepted among progressive thinkers of the next generation. William Whewell, the future Master of Trinity College, Cambridge, for exampled published an uplifting monograph, On the Plurality of Worlds, in 1850.133

Despite these apocalyptic conclusions, Herschel was beginning to be regarded as a kindly, silver-haired old sage. For all his remote speculations, there was said to be something disarmingly boyish about him. The poet Thomas Campbell was surprised to find him, with his son John, on holiday in Brighton in September 1813. John, incidentally, was ‘a prodigy in science and fond of poetry, but very unassuming’. Campbell was completely captured by the ‘great, simple, good old man’, as he called Herschel: ‘Now for the old astronomer himself: his simplicity, his kindness, his anecdotes, his readiness to explain-and make perfectly perspicuous too-his own sublime conceptions of the universe are indescribably charming. He is 76 [actually Herschel was then seventy-four], but fresh and stout, smiling at a joke…Anything you ask, he labours with a sort of boyish earnestness to explain…I asked him if he thought the system of Laplace to be quite certain, with regard to the total security of the planetary system, from the effects of gravity losing its present balance? He said, “No”.’

Campbell overlooked the startling bluntness of this reply, and its implication that the solar system could easily fly apart (or else implode). Instead he went on to record amiable chat about the newly discovered ‘asteroid’ belt between Mars and Jupiter. Herschel had actually named ‘asteroids’ himself in an earlier letter to Banks,134 and murmured, ‘remember there will be thousands more-perhaps 30 thousand-not yet discovered’. Herschel also mentioned applying Newton’s theories for measuring the speed of solar light to ‘inconceivably distant bodies’ in the stellar system, with unimaginable results. ‘Then speaking of himself, he said with a modesty of manner that quite overcame me, when taken with the greatness of the assertion: “I have looked further into space than ever human being did before me. I have observed stars of which the light, it can be proved, must have taken millions of years to reach the earth.”’

Campbell recalled that he felt he had been ‘conversing with a supernatural intelligence’. Finally, Herschel completely perplexed the poet by remarking that many distant stars had probably ‘ceased to exist’ millions of years ago, and that looking up into the night sky we were seeing a stellar landscape that was not really there at all. The sky was full of ghosts. ‘The light did travel after the body was gone.’ After leaving Herschel, Campbell walked onto the shingle of Brighton beach, gazing out to sea, feeling ‘elevated and overcome’.135 He was reminded of Newton’s observation that he was just a child picking up shells on the seashore, while the great ocean of truth lay all before him.136

 Adams never forgot this spirited meeting with Herschel. Years later, in 1825, he wrote to Thomas Jefferson, his successor as President, complaining of the orthodox Christian beliefs of most British scientists, and advising Jefferson not to hire them to teach at the University of Virginia, where he was Chancellor. Adams contrasted these scientists’ attitudes with Herschel’s untrammelled vision: ‘They all believe that great Principle which has produced this boundless universe, Newton’s universe and Herschel’s universe, came down to this little ball [planet earth], to be spit upon by the Jews. And until this awful blasphemy is got rid of, there never will be any liberal science in the world.’ This argument would presumably have been satisfactorily concluded the following year, when both Adams and Jefferson died and went to meet the Great Principle. See Michael J. Crowe, The Extraterrestrial Life Debate (1986).

 In modern times the passage of Hale-Bopp (1997) inspired a mass suicide by the Heaven’s Gate cult, though that was in California. Even today, great uncertainty surrounds comets. Little more than 1,000 periodic comets have been identified, although several have been visited by space probes. Just as James Thomson suspected, they partly consist of frozen water, and have been described less romantically as ‘dirty snowballs’ of ice and rock. But current geophysical speculation that comets, as well as volcanoes, may have caused sudden catastrophic climate changes on planet earth in the past curiously brings back their role as portents of disaster. See the chapter ‘Geology’ in Natalie Angier’s exuberant study of current scientific thinking, The Canon: The Beautiful Basics of Science (2007).

 Although there are many dissimilarities, not least that of age, it is interesting to compare Caroline’s situation with that described in Dorothy Wordsworth’s journal on the day her beloved brother William married their friend Mary Hutchinson in October 1802 at Grasmere. ‘At a little after 8 o’clock I saw them go down the avenue to the Church. William had parted from me upstairs. I gave him the wedding ring-with how deep a blessing! I took it from my forefinger where I had worn it the whole of the night before-he slipped it again onto my finger and blessed me fervently. When they were absent…I could stand it no longer, and threw myself on the bed, where I lay in stillness, neither hearing or seeing anything.’ Unlike Caroline, Dorothy contented herself with deleting only a single sentence of her journal, the one about wearing William’s wedding ring (Grasmere Journal, October 1802). For a subtle and tender account see Frances Wilson, The Ballad of Dorothy Wordsworth (2008).

 Lalande had published a popular guide to astronomy for women, Astronomie des Dames (1795), in which he gave the history of women astronomers, beginning with the legendary Hypatia of Alexandria (also to be praised by Humphry Davy in his lectures) and continuing with Voltaire’s mistress Émilie du Châtelet, who translated Newton into French. Caroline Herschel is described as the ‘great comet hunter’, renowned throughout Europe for her ‘proficiency’. The book was subsequently translated into English with the anodyne title of Astronomy for Ladies (1815). See Claire Brock, Comet Sweeper: Caroline Herschel’s Astronomical Ambition (2007).

 Something oddly similar happened in the Wordsworth household, when Dorothy Wordsworth became deeply attached to her brother’s first child, her nephew John Wordsworth, who was born in 1803, with Dorothy and Coleridge as his godparents. Dorothy nursed and played with John, who always remained Aunt Dorothy’s favourite, while Wordsworth doted on his beautiful daughter Dora (much to her discomfort in later adulthood). Dorothy even acted for several years as John’s devoted housekeeper, after he grew up and became a rather solemn young clergyman.

 Coleridge seized on this idea in a late essay: ‘Kepler and Newton, by substituting the idea of the Infinite-for the idea of a finite and determined world assumed in the Ptolemaic Astronomy-superseded and drove out the notion of one central point or body of the Universe. Finding a centre in every point of matter and an absolute circumference nowhere, they explained at once the unity and the distinction that co-exist throughout the Creation by focal instead of central bodies. The attractive and restraining power of the sun or focal orb, in each particular system, supposing and resulting from an actual power, present in all and over all, throughout an indeterminable multitude of systems. And this, demonstrated as it has been by science, and verified by observation, we rightly name the true system of the heavens’-Church and State (1830). Hubble put this simply and beautifully: ‘Our stellar system is a swarm of stars isolated in space. It drifts through the universe as a swarm of bees drifts through the summer air’-Edwin Hubble, The Realm of the Nebulae (1936).

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