The Age of Wonder

by Richard Holmes

  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.

  4

  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 multi
verses). ‘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 Systéme 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 outspoken). 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 sm
ile 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