The Reflecting Telescope

The close of the year 1671 was marked by the public appearance of Newton upon the national stage of the Royal Society of London. It is strange that with both Newton and his arch-rival Leibniz this event happened in the same unexpected and unlikely way: each of them presented a gadget to the Royal Society. In Leibniz's case it was an arithmetical machine, a toothed-wheel device of the type pioneered by Blaise Pascal, in Newton's his miniature reflecting telescope. Newton's introduction to the Society (December 1671) preceded Leibniz's by just over a year. Both men were, for their pains, severely mauled by Robert Hooke, with assertions that their inventions were valueless and much inferior to his own schemes. Both were deeply wounded by this reception, though also conscious of the warmer welcome extended to them by other Fellows of the Royal Society, not least its Secretary, Henry Oldenburg.

Newton and Leibniz certainly did not meet during this first visit of Leibniz to London (January–March 1673), though before long Collins would be sharing with Leibniz an outline of the mathematical progress accomplished by James Gregory and Isaac Newton. Yet curiously there may be a link between Leibniz and Newton's reflecting telescope. In a letter that Oldenburg received probably about 20 October 1671, Leibniz (writing about the innovations made by a young German optician) mentioned ‘Tubos Catadioptricos, quales mihi in mentem venerunt’ (‘reflecting-refracting tubes, such as occurred to my mind’). No explanation of this phrase has been found, but Newton had certainly invented a catadioptrical telescope.

Warden of the Mint, 1696

It is a fair guess that Newton was never fully content with his professorial and collegiate life in Cambridge after the university had sent him to Parliament in 1689. Indeed, it may be that his eye began to rove as early as 1687, in the period of lassitude that must inevitably have followed the intense and exciting task of bringing the Principia to a conclusion in the summer of that year. By that time the acquaintance or friendship between Samuel Pepys PRS and Isaac Newton must have been established; besides the Royal Society, Christ's Hospital mathematical school had brought the two men together. Pepys was then at the height of his career and of his influence. At the peak of his psychological crisis in 1693 Newton wrote to Pepys: “I never designed to get anything by your interest, or King James favour,” an obvious allusion to days before the Revolution, after which Pepys's influence was nil. If we may read this anxious denial as evidence that there really was some such talk or manoeuvre (as with Newton's parallel denial to Locke), it must have occurred in 1687 or 1688.

Similarly and in the same disturbed frame of mind, Newton wrote to Locke: “I beg your pardon also for saying or thinking that there was a designe to sell me an office.” In this case, letters do hint at Locke's enlisting the help of the Earl of Monmouth (a favourite of William Ill's and recently First Lord of the Treasury) who had been a patron of Locke himself.

Our society depends upon science, and yet to many of us what scientists do is a mystery. The sciences are not just collections of facts, but are ordered by theory, and this is where Einstein's famous phrase about science being a free creation of the human mind comes in. Science is a fully human activity; the personalities of those who practise it are important in its progress and often interesting to us. Looking at the lives of scientists is a way of bringing science to life.

By the time of his death in 1727 Newton stood as the representative figure of modern science. His name was something to conjure with, evoking ideas of the absent-minded professor, the solitary genius, and the power of mathematical and experimental science to answer questions about the world. He became a key figure in the Enlightenment of the eighteenth century, and his work correspondingly aroused unease among Romantics who saw his science as inhuman and reductive.

A mythical Newton, a new Adam born on Christmas Day and nourished by an apple from the tree of knowledge, came to obscure the real man who had worked in dynamics, astronomy and optics, and less successfully in chemistry, to synthesize the work of great predecessors such as Kepler, Galileo, Descartes and Boyle. Rupert Hall comes to this biography after editing the correspondence of both Newton himself and also Henry Oldenburg, the first secretary of the Royal Society and the editor of its journal. He has also edited some of Newton's unpublished papers.

Newton first took up residence in a house in Jermyn Street (now number 88) towards the socially superior western end, in which he lived four years, then from 1700 to 1709 in the next-door house (87). Sir Robert Gayer was a near neighbour (letter 710). Leases for these properties had been granted by the trustees of the Earl of St Albans in 1665, and the buildings were put up about ten years later. Number 87 is at present undergoing total reconstruction and number 88 is a shop (‘James Bodenham’) with the original brick structure preserved.

After his brief sojourn in Chelsea (where he lived at the east end of Paradise Row) Newton moved to 35 St Martin's Street, a few yards south of Leicester Fields (now Square), an area just newly developed by Lord Leicester. There he lived in a house built c.1695 from 1711 to 1725. It had three storeys with basement and was built of brick with a tiled roof; there was a bracketed hood over the front door. On the main floors were rooms front and back with a projecting ‘closet’ wing at the rear. The ground-floor front room was panelled. According to a footnote in the Survey of London Newton had a small observatory built at the top of the house.

In Kensington he lived (in lodgings?) in Orbell's Buildings, a little north of Kensington High Street and west of Church Street, a site now occupied by Bullingham Mansions. He already owned property south of the High Street.

Newton was painted at least seventeen times by seven or more artists: Sir Godfrey Kneller depicted him four times, Sir James Thornhill and John Vanderbank twice. In addition one may examine a death mask, ivory medallions made by David Le Marchand at various dates and an excellent medal in profile (1726) by Newton's Mint artist, John Croker. All these images of Newton, except the 1689 Kneller (of which at least two versions exist) were made after Newton's move to London, hence after the age of sixty (Kneller, 1702). Many of the portraits were engraved and widely circulated.

Three of especial interest are the 1689 Kneller painting of Newton with a youthful, alert, intellectual appearance, of which the original has always been in the family; the 1720 Kneller painted for Pierre Varignon; and the 1725 Vanderbank, commissioned by the Royal Society and still hanging in its rooms.

Of the second, showing Newton at the age of seventy-eight, Varignon remarked that he appeared no more than fifty years old, yet Brook Taylor had assured him of its excellence as a likeness. Stukeley, present at the ‘sittings’ for this portrait, wrote that ‘it was no little entertainment to hear the discourse that passed between these two first men in their way. tho it was Sir Isaac's temper to say little, yet it was one of Sir Godfrey's arts to keep up a perpetual discourse, to preserve the lines and spirit of a face’ (Memoirs, 1936, pp. 12–13). This portrait was later acquired in Paris by Lord Egremont and now hangs at Petworth.

When his work ceased, the story of Newton's life ended. William Stukeley and John Conduitt – the latter in a memoir sent to Fontenelle, then writing his éloge of Newton as a membre étranger of the Académie Royale des Sciences – agree that his decay began with ‘a relaxation of the sphincter of the bladder; so that he was oblig'd to make water frequently’. Newton curtailed his social life and dined simply: ‘chiefly upon broth, vegetables, and fruit, of which he ate very heartily’. This was about 1722. In August 1724 he passed a bladder-stone, without much pain, and in the following winter suffered bronchitis (or worse). Temporarily, he was much improved in general health by moving out to the village of Kensington, in country air, though he suffered an attack of gout. Through two good years he worked on the third Principia with Pemberton. It was on 7 March 1725 that he had a ‘curious conversation’ with Conduitt about his notion of a secular revolution in the cosmos, whereby matter from the Sun was condensed into bodies, becoming planets, then comets which ultimately fall into the Sun, and so falling may destroy the Earth by fuelling the Sun to excessive heat. Man's duration on Earth Newton took to be brief: for all arts and sciences had been discovered ‘within the memory of history, which could not have happened, if the world had been eternal; and … there were visible marks of ruin upon it which could not be effected by a flood alone.’

Hooke and Newton, 1679–80

Recently D. T. Whiteside has published an authoritative article on the evolution of the Principia from 1664 to 1686, following hard upon a large volume of facsimiles of the relevant documents. My account here, therefore, may be confined to bare essentials, especially as so little is known of Newton's personal life in the period of most intense effort devoted to his great work, that is, from the summer of 1684 to the late spring of 1686, when his surviving correspondence with Edmond Halley opens. Of the dozen extant letters from this period of some twenty-six months, no fewer than nine concern Flamsteed's putative provision of astronomical data for use in the Principia.

We must go back to chapter 6, where we left Robert Hooke enticing Newton (against his desire) into a philosophical correspondence. In a rejoinder of 9 December Hooke returned to Newton's carelessly considered spiral of descent, ending at the centre of the globe, as sketched in his letter to Hooke of 28 November 1679 (see figure 6.1). Regretting Newton's renunciation of philosophy as ‘a little Unkind’ and disclosing that he had read Newton's reply to his first approach at a meeting of the Royal Society, Hooke agreed, as had other Fellows then present, that a weight would fall to the east of its point of departure, not the west.

“The same year I found the method of Tangents …”

The origins of Newton's principal innovations in mathematics and science are to be found in the records of his reading as an undergraduate; immediately after these studies came “the prime of my age for invention” which Newton placed in 1665 and 1666. In mathematics and optics the transition from reading to original investigation can be perceived (though not exactly dated). In mechanics, on the other hand, we find Newton's earliest discovery on the first page of his “Waste Book” (Cambridge University Library MS Add. 4004), where the tenth page is dated “Jan 20th 1664” (that is, 1665 in our reckoning). No known annotation from Galileo or any other likely source antedates the “Waste Book”. From this and other dates in the notebooks it is evident that Newton's great epoch of creative scientific work began some months before the start of the year 1665, while he continued to mine the rich veins that he had opened as late as (probably) 1668. The two years of Newton's reminiscences stretch more accurately to three or more, of which 1665 and 1666 were central and critical.

That a large portion of this creative epoch was passed in Lincolnshire – not by any means altogether at home in Woolsthorpe, but probably also at Grantham and certainly at Boothby Pagnell – was a matter of chance. Not for the first time, Cambridge University was closed by plague. Bubonic plague had been endemic in Britain since the great pandemic of the mid-fourteenth century; the last major outbreak had been in 1625.

The Queries in Opticks

The last quarter of Newton's life was distinguished from the first three-quarters by the profusion of his written work that was published by himself or by others for him. As always with Newton, none of this publication was fundamentally new: his intellectual effort was devoted to making more perfect what had been published before (as with the Principia and Opticks), to bringing to light from his files writings and correspondence of long ago (as with Commercium Epistolicum), or to polishing for the benefit of posterity the results of studies that he had pursued for decades (as with The Chronology of Ancient Kingdoms Amended and The Prophecies of Daniel and John). In making this point I do not mean quite to assert that, had Newton died in 1705, it would have been possible to reconstruct from his papers all that was subsequently published under his name. Only of the posthumous System of the World would this be exactly true. On most of the late books Newton was always at work, modifying, adding new material from experiments and reading, extending and revising.

Of the Queries appended to the successive editions of Opticks this is particularly true. The main text of this book was not greatly changed when it was republished in Latin in 1706, nor indeed in the subsequent English editions. The Queries, however, developed into the most important series of statements that Newton released to the public about the deepest questions of natural philosophy: the concepts of matter and force, the possible role of an aether and the relation of God to the universe.

On the first of March, 1704, David Gregory noted in his diary that Newton had been ‘provoked by Dr Cheyns book to publish his Quadratures, and with it, his Light & Colours, &c.’ And just one month later Newton indeed signed and dated his “Advertisement” to this volume. Some sixteen months had passed since he had promised ‘Mr [Francis] Robarts, Mr Fatio, Capt. Hally & me to publish his Quadratures, his Treatise of Light, and his treatise of the curves of the 2d Genre [sic]’. In the interval Robert Hooke had died, thus clearing the way for the publication of Opticks,a book which Newton had sworn to keep to himself so long as Hooke lived. Opticks, like the pair of mathematical treatises that was to appear with it, had been long anticipated by Newton's friends. In 1694 Gregory had examined its three Books – hence it was substantially complete then, though Newton was not yet ‘fully satisfied about a certain kind of colours and the way of producing it’ – and summarized it in his diary of his visit to Cambridge (5 to 7 May). Newton meant to publish it after leaving the university, in English as it was written, or translated into Latin if he remained at Cambridge. By April 1695 John Wallis at Oxford knew of it (through Flamsteed's protégé Caswell) as ‘a Treatise about Light, Refraction and Colours’ already completed. ‘Tis pitty it was not out long since. If it be in English (as I hear it is) let it, however, come out as it is; & let those who desire to read it, learn English.’ Thus spoke this fervid Englishman! Through successive letters Wallis continued to prod Newton, but he would not budge.

The Master of Arts

After looking so far forward to the origins of the Principia, it comes almost as a shock to realize that young Isaac Newton was still barely twenty-four years old, not yet a Master of Arts, when he returned to Cambridge in 1667. It would be strange indeed if he were not now far more conscious of his own potentiality in the world of learning than he had been before the plague. Five years into the future he would be arguing for his own discoveries on equal terms with the acknowledged leaders of the scientific movement in Europe. As yet, however, he stood on the lowest rung of the ladder of academic promise and his name was unknown. Newton had a chance of a minor fellowship at Trinity College at the next election, in the coming October, and no doubt hoped for something from the support of his family connection, Humphrey Babington. Candidates for the fellowship had to submit, at least in theory, to four days of oral examination by the Seniors in the college chapel. By whatever means, and whoever was convinced of his merits, Newton was indeed among the chosen. He was assigned the ‘Spiritual Chamber’ to reside in, but probably remained where he was with his friend (and amanuensis) John Wickins, renting out the room allotted to him. Trinity College now paid him ‘wages’ of £2 per annum, gave him allowances for livery and commons (that is, clothing and food) and allowed him his share (‘dividend’) of the college revenues. Trinity also assigned him his first pupil, a Fellow-commoner named St Leger Scroope, who made no mark in history.

In response to my request, some years ago, Professor Karin Figala prepared an elementary account of the results of her investigation of Newton's alchemical papers and related documents. This was communicated to me privately in March 1984. In the following paragraphs Professor Figala's summary is printed, with her permission. For her technical paper on this material, see ‘Die exakte Alchemie von Isaac Newton’ in Verhandlungen der Naturforschenden Gesellschaft Basel 94, 1984, pp. 157–228.

The search for a combination of the exact sciences with magical thought was a central motive of the seventeenth-century attitude of mind: Newton was no exception to this rule. His personal attitude towards the problem is best illustrated by his (al)chemical research, for he seems to have seen in traditional alchemy – which he considered to be of divine origin – a possible synthesis of seemingly divergent lines of thought. He was convinced that God had arranged everything in Heaven and on Earth according to number and measure, thus sharing the firm belief of the ancient Pythagoreans. Harmonic proportion seems to be a key concept in Newton's thought, as mirrored in his theory of the material world. In fact, his theory of the composition of matter – laid down in principle in Opticks – centres on the material world; accordingly, contemporary alchemy immediately presented itself to his mind. It is in Newton's ‘rational alchemy’ that we can get hold of at least a small part of his attempt to reconcile magic and science.

In Newton's theory of the composition of matter, seemingly impenetrable particles are built up from cubic elementary cells, some of which hold matter, some of which do not.

Swift was in England from November 1707 to May 1709 and from September 1710 to the middle of 1713, on Irish Church business. His first known reference to Catherine Barton is in his terse accounts, where he notes a loss of two shillings at ombre, at ‘Barton's’ on 4 December 1708. Twelve days later he was there again, suffering very bad ‘fitts’ of his habitual giddiness; he was forced to take a chair home, instead of walking as usual, and next day rewarded Mrs Barton's servants with the large present of 7s.6d in gratitude for their attentions. In April, July and August 1709 he recorded letters from Catherine, and on 26 May 1709 one written to her.

During his second and longer visit to England Swift noted in his journal for ‘Stella’ (Esther Johnson) that he dined with Mrs Barton three times in thirty-three months (28.ix.1710; 30.xi.1710; 7.iii.l711); he records visits to her on nine further occasions (19.xii.1710; 23.i.l711; 2.iv.l711; 10.iv.1711; 6.vii.l711; 18.vii.1711; 14.X.1711; 25.x.1711; 20.xii.1711). It is notable that by his own record Swift saw nothing of Mrs Barton during the whole of 1712, nor during the six months of 1713 that he spent in London.

During his first visit to London Swift associated with the Whigs and became friendly with Halifax, among others. He never in any way connected Halifax with Mrs Barton, though he continued to meet both during his second visit to London, when he supported the Tory interest (and therefore disputed with Mrs Barton, who like her uncle was a Whig).

In his translation of Hermann Boerhaave's Elements of Chemistry (1741) Peter Shaw wrote: ‘It is by means of chemistry, that Sir Isaac Newton has made a great part of his surprizing discoveries in natural philosophy,’ an opinion which becomes more understandable, if no less extravagant, when related to Shaw's wide claim that ‘chemistry, in its extent, is scarce less than the whole of natural philosophy.’ Such a high view of chemistry would not have been expressed a century earlier, indeed the rise of chemistry as a department of natural philsophy had taken place in Newton's lifetime. In this rise the writings of Robert Boyle had played a principal part, exercising (as we have seen) considerable influence over Newton himself. Many considerations lead me to believe that Newton's chemical atomism was Boyle's corpuscular chemistry revised, made more precise and rendered more complete, but also more deeply speculative. However, as Shaw correctly states, the Queries in Newton's Opticks had done much to enhance chemistry's reputation as a branch of theoretical science, the science of matter.

When Newton's chemical interests first took shape, Opticks and its Queries were still half a century in the future. It would be rash indeed to extrapolate the sophisticated atomist theory of chemical reaction found in them back into Newton's initial experiments of the late 1660s. No positive statements can be made about their date, nor about what book or which individual may have inspired Newton to attempt this kind of investigation.