Sir Isaac Newton
O N A certain Christmas morning, two hundred and seventy-five years ago (the date was 1642, just eleven months after the death of Galileo), when the bells of Colsterworth were ringing, and the folk were wending their way to church, a fatherless child was born in the old manor-house of Woolsthorpe, about 8 miles south of Grantham in Licolnshire. The child was a boy of so diminutive a size and so feeble a frame that his life was despaired of from the first, and two women who were sent to the house of a neighbour at North Witham to procure some strengthening medicine for the infant, did not expect to find him alive on their return. 'Providence, however, had otherwise decreed; and that frail tenement, which seemed scarcely able to imprison its immortal mind, was destined to enjoy a vigorous maturity, and to survive even the average term of human existence.'
The child was named Isaac after his father, Isaac Newton, who had died shortly after his marriage to Hannah Ayscough. The father's station was that of a yeoman, who owned and farmed the small estate of Woolsthorpe, which had been in the possession of his family for about a hundred years. The manor, we are told, was worth only £30 a year, but Mrs. Newton owned another property at Sewstern, in the neighbouring county of Leicestershire, which brought her income up to about £80, and with these slender means, aided by the cultivation of the little farm on which she resided, she supported herself and her child. Some two years after Isaac's birth the widow married the Rev. Barnabas Smith, the rector of North Witham, to whom she had been recommended as 'an extraordinary good woman', and when she went to reside at the Rectory little Isaac was left at Woolsthorpe in the charge of his grandmother, Mrs. Ayscough.
Of Isaac's childhood nothing is known beyond the fact that he attended two village schools at Skillington and Stoke. At the age of twelve he was sent to the grammar school at Grantham, kept by a Mr. Stokes, and was boarded with Mr. Clark, an apothecary in the town. He seems to have been a very indifferent scholar at first, and consequently was placed very low in the school. One day a boy above him administered a kick which aroused Isaac's temper, and in the fight which followed Isaac came off victorious. This proved to be the stimulus necessary to awaken his dormant faculties; Isaac was determined to get above his antagonist. By sticking to his books he at length accomplished this feat, and thenceforth continued to rise until he became head of the school. The fight had made him popular, and his popularity was increased by his cleverness in constructing mechanical toys. Amongst other things he made a working model of a windmill which had been erected near the town; this he fixed on the roof of his lodging so that it could be turned by the wind. Another of his contrivances was a water-clock, the hands of which were moved by a piece of wood which either fell or rose by the action of dropping water. The clock stood in his bedroom, and he supplied it every morning with sufficient water to keep it going for the day; it was used as a clock by the Clark family, and remained in the house long after its inventor had quitted Grantham. He also made kites on scientific principles for his schoolfellows, and paper lanterns to light his way to school on winter mornings. On a dark night he would tie on fo these lanterns on to the tail of his kite so as to make the country people believe they had seen a comet. He seems also to have had some talent for drawing, for Mr. Clark told Dr. Stukely when the latter visited Grantham that the walls of Newton's bedroom 'were covered with charcoal sketches of birds, beasts, men, ships, and mathematical figures, all of which were very well designed. These were all framed by his own hands.
Upon the death of the Rev. Barnabas Smith in 1656 the widow returned to Woolsthorpe with her three children, Mary, Benjamin, and Hannah Smith, and Newton was called home to help his mother on the farm. As may be imagined, the student, who was now as forward with his studies as at first he had been behindhand, was not very willing to exchange his books for the plough. Isaac obeyed his mother's wishes, however, and undertook his duties cheerfully; but on Saturday mornings, as this was market-day at Grantham, he was sent in the company of an old servant to the town to sell grain and purchase necessaries for the house. Newton, however, left the old woman to do the marketing, and betook himself to his garret at the apothecary's, where he spent the time reading books borrowed from Mr. Clark's parlour. After a while he took to deserting his companion at an earlier stage of the journey, and ensconcing himself in a hedge beguiled the time with a book till the servant returned from Grantham. 'The perusal of a book, the execution of a model, or the superintendence of a water-wheel of his own construction, whirling the glittering spray from some neighbouring stream, absorbed all his thought; whilst the sheep were going astray, and the cattle were devouring or treading down the corn.'
His thoughts, too, were now turned to the movements of the celestial bodies. Remembering the imperfections of his water-clock, he sought to obtain a more accurate measurement of time by observations of the sun. He traced the sun's passage upon the walls of the house and garden, and having marked the hourly and half-hourly subdivisions by means of fixed pins, he constructed two sun-dials. One of these, known as 'Isaac's dial', was constantly referred to by the neighbours to learn the hour of the day, and was in existence at Woolsthorpe long after Newton's death.
Isaac's presence at the farm seemed to promise small benefit either to his mother or himself, and at length his uncle, Mr. William Ayscough, the Rector of Burton Coggles, wisely went to the mother and urged her not to thwart the young man in his pursuits, but to send him back to Grantham to complete his studies with a view to going to Cambridge. The widow decided to accept this good advice, and as Mr. Ayscough was himself a Trinity man Isaac entered that college in the ensuing term.
He became a scholar in 1664, and took his B.A. degree in the following year. In 1667 he was made a Junior Fellow of his college. He proceeded m.A. in 1668, and in the same year was appointed to a Senior Fellowship. In 1669, at the age of twenty-seven, he was appointed to the Lucasion Chair of Mathematics on the resignation of his friend and tutor, Dr. Barrow.
Dr. Barrow's lectures were, in fact, the means of drawing Newton's attention to the subject of light, in which he was destined to make some of his most brilliant discoveries. We learn of his going to Stourbridge fair to buy a prism for the purpose of testing Descarte's theory of colours; and his account-book for 1664, containing the entry relating to the purchase, has been preserved. His experiments, however, according to his own account, appear to have been begun in 1666. Thus he says: 'In the beginning of the year 1666 … I procured me a triangular glass prism to try therewith the celebrated phenomena of colours'; and he adds: 'Amidst these thoughts I was forced from Cambridge by the intervening plague, and it was more than two years before I proceeded further.'
During this enforced absence from Cambridge, Newton's thoughts were first turned to the subject of universal gravitation. 'As he sat alone in a garden' (says Henry Pemberton, his intimate friend of later years), 'he fell into a speculation on the power of gravity; that as this power is not found sensibly diminished at the remotest distance from the centre of the earth to which we can rise… it appeared to him reasonable to conclude that this power must extend much further than is usually thought. Why not as high as the moon? Said he to himself, and, if so, her motion must be influenced by it; perhaps she is retained in her orbit thereby.'
We owe the story that this train of thought was started by the fall of an apple from the tree to Voltaire, who received it from Newton's step-niece, Mrs. Conduitt. There is, fortunately, no reason to doubt its truth. For many years tradition pointed out the tree in the garden at Woolsthorpe, and it was shown to Sir David Brewster when he visited the spot in 1814. In 1820 the tree was cut down, but a portion of the wood was preserved.
It would be unjust, as well as mistaken, to ignore the fact of Newton's indebtedness to those who had patiently wrestled with the great problems of the heavens and established the laws by which they were governed upon a scientific footing. It is sometimes stated that Newton 'discovered' the force of gravitation; whereas in reality he did nothing of the sort. Gravitation—i.e. the attractive force exercised by the earth upon objects resting upon its surface—was a commonly accepted theory long before Newton's time. What Newton did was to demonstrate by the aid of mathematical science the existence of a universal law of gravity extending throughout the whole of space—to show that the force which acted at the surface of our globe did not belong exclusively to the earth, but extended to and was shared by every one of the celestial bodies, however distant from the earth; and that these bodies acted and reacted upon one another in a degree of intensity regulated by their relative sizes and the distances which separated them.
Having made his calculations with regard to the supposed influence of the earth's attraction upon the moon and compared these with the observed motions of that planet, however, Newton found that the two things were not, as he had hoped, in exact agreement. 'I found them,' to use his own words, 'answer pretty nearly'; but this was not enough for his purpose. There was a discrepancy, for which he could not account at the time, between his theory and the known facts regarding the moon's motions; and so he quietly laid his proofs aside; the fact was that Newton, in order to make his calculation, had been compelled to rely upon the estimate then in use among geographers, which was based on the supposition that a degree of latitude contained 60 miles. But, as Pemberton says: 'As this is a very faulty supposition, each degree containing about 69½ of our miles, his computation did not answer expectation, whence he concluded that some other cause must at least join with the power of gravity on the moon.' As this cause was unknown to him he abandoned his investigations till in 1671 a fresh series of measurements by a French observer named Picard was published at Paris, giving 69 1/10 miles to the degree; and this discovery was announced at a meeting of the Royal Society early in 1672. Newton was then a Fellow of the Society, and 'when he repeated his work with Picard's numbers some years later, he found an exact agreement between the theory and the fact'.
'Every body in the universe attracts every other body with a force which varies inversely as the square of the distance.' The establishment of this profound and universal law we owe to the genius of Newton, but for five years the world remained in ignorance of his achievements; in the month of August, 1684, a visit paid to Newton at Cambridge, by Halley, the astronomer, elicited the fact that Newton had solved the great problem of the elliptical path of the planets some years before, but that he was unwilling to make it public. Halley's own account of the matter is given in a letter to Newton, dated June 29, 1686; the object in writing the letter being to clear up a dispute regarding the claim of Robert Hooke to have been the first to solve the problem in question. In this letter Halley says: 'And this I know to be true, that in January, 1684, I, Having from the consideration of the sesquialterate proportion of Kepler concluded that the centripetal force decreased in the proportion of the squares of the distances reciprocally, came on Wednesday to town, where I met with Sir Christopher Wren and Mr. Hooke, and falling in discourse about it, Mr. Hooke affirmed that upon that principle all the laws of the celestial motion were to be demonstrated, and that he himself had done it. I declared the ill-success of my own attempts, and Sir Christopher, to encourage the inquiry, said he would give Mr. Hooke or me two months' time to bring him a convincing demonstration thereof, and, besides the honour, he of us that did it should have from him a present of a book of forty shillings. Mr. Hooke then said he had it, but would conceal it for some time, that others, trying and failing, might known how to value it when he should make it public. However, I remember that Sir Christopher was little satisfied that he could do it; and though Mr. Hooke then promised to show it him, I do not find that in that particular he has been as good as his word. The August following, when I did myself the honour to visit you, I then learned the good news that you had brought this demonstration to perfection; and you were pleased to promise me a copy thereof, which the November following I received with a great deal of satisfaction from Mr. Paget [mathematical master at Christ's Hospital].' W. W. Ball's Essay on Newton's Principia, 1893
On April 28, 1686, the MS. of the first book of the Principia was presented to the Royal Society. Dr. Birch, in his History of the Society already quoted, says: 'Dr. Vincent presented to the Society a manuscript treatise entitled Philosophiae Naturalis Principia Mathematica, and dedicated to the society by Mr. Isaac Newton, wherein he gives a mathematical demonstration of the Copernican hypothesis, and makes out all the phenomena of the celestial motions by the only supposition of a gravitation to the centre of the sun decreasing as the squares of the distance reciprocally. . . .'
The Principia was published in 1687, about mid-summer (it is undated). The MS. is preserved in the Royal Society's library, but it is not in Newton's handwriting. 'It consists, says Brewster, 'of three books. The first and second, which occupy three-fourths of the work, are entitled On the Motion of Bodies—the first treating of their motions in free space, and the second of their motions in a resisting medium; whilst the third bears the title, On the System of the World. The first two books contain the mathematical Principles of Philosophy, namely, the laws and conditions of motions and forces. . . . The object of the third book is to deduce from these principles the constitution of the system of the world; and this book has been drawn up in as popular a style as possible, in order that it may be generally read.'
We are told that 'the conclusions of the Principia excited almost as much interest, however, among philosophers and literary men as among mathematicians.' W. W. Ball's Essay on Newton's Principia. For instance, the Earl of Halifax appealed to Newton to know whether there was any way of mastering the subject except by the aid of mathematics. Newton replied that it was impossible. Thereupon the nobleman set himself to learn mathematics from Machin, to whom he gave fifty guineas as an encouragement; but he found the task too hard, and abandoned it in despair. Though there were numerous readers, there were at first but few converts to the new order of things. By many of the philosophers on the Continent (where Descartes's system still reigned supreme) Newton's discoveries and conclusions were resisted with all the strength which long-standing error and deep-rooted prejudice could bring to bear against them; and it was not until long after Newton himself had passed away that the truths expounded in his Principia were accepted by the scientific world of Europe.
Newton's position in the eyes of his countrymen was always deservedly high, though he remained for long in comparatively poor circumstances. How poor at the time when he was proposed as a Fellow of the Royal Society, and when he was engaged upon his immortal work, may be guessed from the fact that he was excused the weekly payment of one shilling to the society; he had also expressed a wish to resign, alleging as the cause the distance between Cambridge and London.
In 1699 Newton was appointed Master of the Mint, performing his incongruous duties with scrupulous care and efficiency. A distinction he valued more highly was his election to the Presidentship of the Royal Society in 1703. He represented his University in Parliament from 1688 to 1705, and in 1705 he was knighted by Queen Anne.
There are numerous facts and stories concerning Newton, his traits, habits, and personal appearance, and one description, coming from an authentic source, holds us like a charm. Mr. Conduitt (who married Newton's niece) said of Newton that he 'had a very lively and piercing eye, a comely and gracious aspect, with a fine head of hair as white as silver'. In size he was not above the middle height; and he was usually untidy and slovenly in his dress. Humphrey Newton says: 'I never knew him to take any recreation or pastime, either in riding out to take the air, walking, bowling, or any other exercise whatever; thinking all hours lost that were not spent in his studies, to which he kept so close that he seldom left his chamber, except at term time, when he read in the schools. . . . He very rarely went to dine at the hall, except on some public days; and then if he has not been minded, would go very carelessly with shoes down at heel, stockings untied, surplice on, and his hair scarcely combed.' Dr. Stukely, who knew him intimately, also relates that 'when he had friends to entertain, if he went into his study to fetch a bottle of wine, there was danger of his forgetting them'. The same writer tells that on one occasion when Newton was going home to Colstersworth from Grantham, 'he led his horse up Spittlegate Hill, at the town end; when he designed to remount, his horse had slipped the bridle and gone away without his perceiving it, and he had only the bridle in his hand all the while.' He had constantly to be reminded of the fact that he had not dined, and he ate and drank very sparingly at all times. Once when Dr. Stukely called upon him at his college rooms, he found the table laid for dinner, but Newton himself was absent. After waiting for some time, Dr. Stukely, who was aware of Newton's absent-mindedness in regard to meals, resolved to play off a joke upon him. Lifting the cover, he found a roasted chicken, which he devoured, and then replaced the bones on the dish beneath the cover. Presently Newton appeared, and having apologized for his delay, went to the table and lifting the cover disclosed the remnants of the chicken. For a moment he seemed surprised, then he said, 'Ah, I thought I had not dined; but I see I have.'
In London, Newton lived first in Jermyn Street, Piccadilly; then for a short time in Chelsea; afterwards in Haydon Square, Minories, in a house pulled down in 1852. From 1710 until 1727 he occupied a large plain-build brick house (to which he added a small observatory) next Orange Street Chapel, in St. Martin's Street, Leicester Square. A Society of Arts tablet has been placed upon the front of this house. Article 'Newton' in Dictionary of National Biography. For the most part his years were spent at Cambridge, his rooms at Trinity being on the first floor to the right of the staircase leading from Neville's Court. The college authorities built a small observatory for his use on the roof of the Gate Tower. It was in these rooms that the 'distressing accident which some believe to have shaken his great mind for a time' occurred in 1692. The story as commonly received runs as follow: 'One winter morning having shut his pet dog Diamond in his study, Newton came back from early chapel to find all his manuscripts upon the theory of colours, notes upon the experiments of twenty busy years, reduced to a heap of tinder. The dog had knocked down a lighted candle, and set the papers in a blaze. “Ah! Diamond, Diamond, little do you know the mischief you have done,” was the only rebuke the dog received, though, as a Cambridge student writing in his diary at that very time tells us, “Every one thought Newton would have run mad; he was so troubled thereat that he was not himself for a month after.”'
Newton died at Kensington on March 20, 1727, in the 85th year of his age. He was buried in Westminster Abbey on March 28; the grave is immediately below the monument, and on the stone are the words: 'Hic depositum est quod mortale fuit Isaaci Newtoni' ('Here lies what was mortal of Isaac Newton').
In the Chapel of Trinity College is Roubillac's wonderfully fine statue of Newton, given to the college in 1755 by the then Master, Dr. Robert Smith; and in 'The Prelude' we read how, from his bed, Wordsworth loved to gaze on moonlight nights at the windows of the Chapel—
Pope's famous epitaph (which is engraved on a tablet in the room at Woolsthorpe in which Newton was born) echoes the wide appreciation in which Newton's genius was held:—
Newton's own estimate of himself was uttered shortly before his own death: 'I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay still undiscovered before me.'