Authors: Richard Holmes
Tags: #History, #Modern, #19th Century, #Biography & Autobiography, #Science & Technology, #Science, #Philosophy & Social Aspects, #Fiction
On 31 December 1783, New Year’s Eve, over a foot of snow had fallen, and the sky was overcast. William however postponed celebrations, and insisted on the last sweep of the year. Caroline gives the impression that he was particularly impatient, and perhaps shouting at her more than usual. ‘About 10 o’clock a few stars became visible, and in the greatest hurry all was got ready for observing. My Brother at the front of the Telescope [was] directing me to make some alterations in the lateral motion.’ As she hurried round the base of the telescope, ‘having to run in the dark on ground covered foot deep in melting snow’, she slipped and tripped over a hidden wooden stake. These stakes were used to peg down the telescope frame with guy ropes, and had large iron hooks facing vertically upwards, ‘such as butchers use for hanging their joints on’.
Caroline painfully recounted what followed. ‘I fell on one of these hooks which entered my right leg about six inches above the knee. My brother’s call-
make haste!
-I could only answer by a pitiful cry-
I am hooked!
’ She was impaled, like a fish on a barb, and could not move. Herschel was still high up on the observation platform, in complete darkness, and did not immediately realise what had happened. It seems he continued to call down through the dark, ‘
Make haste!
’, while Caroline continued to gasp back in agony, ‘
I am hooked!
’
176
Finally he grasped the situation, and called for help from the assistant who had been adjusting the telescope frame. ‘He and the workman were instantly with me, but they could not lift me without leaving near 2 oz. of my flesh behind. The workman’s wife was called but was afraid to do anything.’ Caroline was carried back to the house, but astonishingly no doctor was called. She bandaged the wound herself, retired to bed, and proudly recorded that she was back on telescope duties within a fortnight. It seems that the extreme cold had an antiseptic effect on the large, open wound, and prevented fatal gangrene.
No doubt it was characteristic of Caroline to treat this wound lightly, and not make any fuss. Yet there is an uneasy sense throughout her account that William did not treat her with sufficient tenderness or care: ’I was obliged to be my own surgeon by applying acquabaseda and tying a kerchief about it for some days.’ The local Windsor physician, Dr James Lind, only heard about the accident a week later, ‘and brought me ointment and lint and told me how to use it’. The deep wound did not heal easily, but there is still no mention of William’s concern at any point. Eventually Dr Lind was called back to Datchet in early February 1784. ‘At the end of six weeks I began to have some fears about my poor Limb and had Dr Lind’s opinion, who on seeing the wound found it going on well; but said, if a soldier had met with such a hurt he would have been entitled to 6 weeks nursing in a hospital.’
177
It is curious that Dr Lind compared Caroline to someone in military service, and it is hard to overlook a certain note of reproach in his words.
♣
Caroline surely intended some irony when she added in the
Memoir:
‘I had however the comfort to know that my Brother was no loser through this accident for the remainder of the night was cloudy and several nights afterwards afforded only a few short intervals favourable for sweeping, and until 16 January before there was any necessity for exposing myself for a whole night to the severity of the season.’
The wound had largely healed by the summer, but it would later return to give her chronic pain in old age. Her pitiful cry-‘
I am hooked!
’-is curiously symbolic of her relations with her brilliant, domineering brother at this period, at a time when he was obsessed by his astronomical ideas to the exclusion of all else. Including, it might seem, his sister’s well-being; although we have only her word for this.
178
It is hardly surprising that Herschel was a little distracted. In 1784 and 1785 he drew together his most radical ideas about the cosmos, and published two revolutionary papers in the Royal Society’s
Philosophical
Transactions.
These completely transformed the commonly held idea of our solar system being surrounded by a stable dome of ‘fixt stars’, with a broad ‘galaxy’ or ‘
via lactae
’ (meaning a ‘path or stream of milk’) of smaller, largely unknown stars spilt across it, roughly from east to west. This was a celestial architecture or ‘construction’, inspired fundamentally by the idea of a sacred temple, which had existed from the time of the Babylonians and the Greeks, and had not seriously been challenged by Flamsteed or even by Newton.
179
‘An Investigation of the Construction of the Heavens’, published in June 1784, quietly set out to change this immemorial picture. It was based on all Herschel’s ceaseless telescope observations, relentlessly pursued with Caroline over two years, with his new twenty-foot reflector telescope. He had identified 466 new nebulae (four times the number recently confirmed by Messier), and for the first time suggested that many, if not all, of these must be huge independent star clusters or galaxies
outsid
e our own Milky Way.
180
This led him on to propose a separate, three-dimensional shape to the apparent flat ‘milk stream’ of the Milky Way. His proposal was based on his new method of ‘gauging’ the number of stars in any direction as seen from the earth, and then deducing from the different densities observed the likely shape of this galactic star cluster
as it would be seen looking ‘inwards’ from another galaxy.
This was a daring mixture of observation and speculation. Herschel’s first galactic diagram appeared like a curious oblong box or tilting parallelogram of stars.
181
But his later calculations produced the now-familiar discus shape of the Milky Way, with its characteristic arms spinning out into space, and the slight bulge of stars at its centre.
182
He was never sure where the solar system was located in the galaxy, and at one point observed that its overall shape was relative, depending on the view as seen by ‘the inhabitants of the nebulae of the present catalogue…according as their situation is
more or less remote from ours
‘.
183
In the second paper, called simply ‘On the Construction of the Heavens’ (1785), Herschel began to develop these ideas into a startling new ‘natural history’ of the universe. He opened by arguing that astronomy required a delicate balance of observation and speculation. ‘If we indulge a fanciful imagination and build worlds of our own…these will vanish like Cartesian vortices.’ On the other hand, merely ‘adding observation to observation’, without attempting to draw conclusions and explore ‘conjectural views’, would be equally self-defeating.
184
His own conjecture would be radical. The heavenly ‘construction’ was not something architecturally fixed by the Creator, but appeared to be constantly changing and even evolving, more like some enormous living organism. His telescopes seemed to show that all gaseous nebulae were actually ‘resolvable’ into stars. They were not amorphous zones of gas left over from the Creation. They were enormous star clusters scattered far beyond the Milky Way, and were dispersed throughout the universe as far as his telescopes could penetrate. The nebulae themselves were active. Their function seemed to be that of constantly forming new stars out of condensing gas, in a process of
continuous creation.
They were replacing stars which were lost.
Herschel found a memorable phrase for this astonishing speculation: ‘These clusters may be the
Laboratories of the universe,
if I may so express myself, wherein the most salutary remedies for the decay of the whole are prepared.’
185
He also pursued the possibility that some nebulae may be ‘island universes’
outside
the Milky Way, thereby hugely increasing the sense of the actual size of the cosmos. Among these was the beautiful nebula in Andromeda, ‘faintly red’ at the centre. By 1785 his nebulae count had risen to well over 900. They appeared ‘equally extensive with that which we inhabit [the Milky Way]…yet all separate from each other by a very considerable distance’.
186
He picked out at least ten ‘compound nebulae’ which he considered larger and more developed than the Milky Way, and imagined the star-cluster view of our own galaxies from theirs. ‘The inhabitants of the planets that attend the stars that compose them must likewise perceive the same phenomena. For which reason they may also be called Milky Ways by way of distinction.’
187
As Kant had speculated, the cosmos might be infinite,
whatever that might mean.
Though Herschel’s estimates of cosmological distances were much too small by modern calculation, they were outlandishly, even terrifyingly, vast by contemporary standards. Beyond the visible parts of our own Milky Way, he estimated that a huge surrounding ‘vacancy’ of deep space existed, ‘not less than 6 or 8 thousand times the distance of Sirius’. He admitted that these were ‘very coarse estimates’. The implications seemed clear, though they were cautiously expressed in his paper: ‘This is amply sufficient to make our own nebula a detached one. It is true, that it would not be consistent confidently to affirm that we were an
Island Universe
unless we had actually found ourselves everywhere bounded by the ocean…A telescope with a much larger aperture than my present one [twelve inches], grasping together a greater quantity of light, and thereby enabling us to see further into space, will be the surest means of completing and establishing the argument.’
188
The dramatic implications of these ideas were soon picked up by journalists and popularisers. The following year Bonnycastle assessed the situation in the first edition of his
Introduction
to
Astronomy:
‘Mr Herschel is of opinion that the starry heaven is replete with these nebulae, and that each of them is a distinct and separate system, independent of the rest. The Milky Way he supposes to be that particular nebula in which our sun is placed; and in order to account for the appearance it exhibits, he supposes its figure to be much more extended towards the apparent zone of illumination than in any other direction…These are certainly grand ideas, and whether true or not, do honour to the mind that conceived them.’
189
Also contained in Herschel’s revolutionary paper of 1785 were the seeds of a new, long-term project. He was planning the building of a monster forty-foot telescope, with a
four-foot mirror.
This would be the biggest and most powerful reflector in the world. With this he believed he could resolve once and for all the problem of the nebulae-whether they were other galaxies far beyond the Milky Way, or merely gas clouds within it. He would also have a better chance of establishing the true distance of the stars, through the measurement of stellar parallax. Above all he believed he would be able to understand how the stars were created, and whether the whole universe was changing or evolving according to some definite law or plan. Finally, he believed he might establish if there were observable signs of extraterrestrial life, a discovery which would have enormous impact on philosophical and even theological beliefs.
There was one other small, but revolutionary, departure in his 1785 paper. For the first time William Herschel carefully credited Caroline in print with a small ‘associate nebula’ in Andromeda. It was a previously unknown cluster ‘which my Sister discovered on August 27 1783 with a Newtonian 2 foot sweeper’. It was not in Messier’s annual catalogue
La Connaissance des Temps,
so this was Caroline Herschel’s first new addition to the universe.
190
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Caroline eventually wrote out two versions of this memoir, the first in summer 1821, when she was seventy, and the second in 1840. She also destroyed two sections of the original record which she did not want read by other family members. A composite version was edited by her great-niece, Mrs John Herschel, and published by Murray in 1769. The manuscript still exists in the private collection of John Herschel-Shorland. The individual Memoirs have been meticulously published by Michael Hoskin, as
Caroline Herschel’s Autobiographies
(2003). William wrote a ‘Memorandum of my Life’ when he was nearly sixty, but this was a sort of professional CV for fellow scientists, comparatively short and characteristically reserved (Herschel,
Scientific Papers
1, p.xiii). For full details see the Bibliography.
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Three of William Herschel’s works are currently available on CD. They are his Oboe Concertos in C major and E-flat major, and his Chamber Symphony in F major (Newport Classics, Rhode Island, USA, 1995). They are notable for their light musical touch and fine, sprightly melodic lines, sometimes with a certain melancholy in the slower passages. The rapid, complex orchestration around the solo oboe in the concertos is handled with great confidence, and suggests Herschel’s ability to manage patterns and counterpoint. This was a conceptual skill which he seemed to transfer (visually) to the patterning of stars and constellations. He moved from earthly music to the music of the spheres.
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A typical brass eighteenth-century orrery showed the sequence of six known planets: Mercury, Venus, Earth, Mars, Jupiter (with moons) and Saturn (with rings) orbiting around a central sun (sometimes operated by clockwork and illuminated by candles). Flamsteed showed all constellations-such as Herschel’s early favourites Orion, Andromeda and Taurus-against mythological engravings of their signs: the Hunter, the Goddess, the Bull. His
Atlas Coelestis
catalogued 3,000 stars; the modern Hubble telescope has identified some nineteen million. But the presentation of the night sky as a curved dome of mythological constellations is still quite usual, as for instance in the magnificently restored curved ceiling of Grand Central Station, New York.