Isaac Newton was born on Christmas-day, 1642 (O. S.), at Woolsthorpe, a
hamlet in the parish of Colsterworth, in Lincolnshire. In that spot his
family had possessed a small estate for more than a hundred years; and
his father died there a few months after his marriage to Harriet
Ayscough, and before the birth of his son. The widow soon married again,
and removed to North Witham, the rectory of her second husband, Mr.
Smith, leaving her son, a weakly child who had not been expected to live
through the earliest infancy, under the charge of her mother.
Newton’s education was commenced at the parish school, and at the age of
twelve he was sent to Grantham for classical instruction. At first he
was idle, but soon rose to the head of the school. The peculiar bent of
his mind soon showed itself in his recreations. He was fond of drawing,
and sometimes wrote verses; but he chiefly amused himself with
mechanical contrivances. Among these was a model of a wind-mill, turned
either by the wind, or by a mouse enclosed in it, which he called the
miller; a mechanical carriage moved by the person who sat in it; and a
water-clock, which was long used in the family of Mr. Clarke, an
apothecary, with whom he boarded at Grantham. This was not his only
method of measuring time: the house at Woolsthorpe, whither he returned
at the age of fifteen, still contains dials made by him during his
residence there.
Mr. Smith died in 1656, and his widow then returned to Woolsthorpe with
her three children by her second marriage. She brought Newton himself
also thither, in the hope that he might be useful in the management of
the farm. This expectation was fortunately disappointed. When sent to
Grantham on business, he used to leave its execution to the servant who
accompanied him, and passed his time in reading, sometimes by the
way-side, sometimes at the house of Mr. Clark. His mother no longer
opposed the evident tendency of his disposition. He returned to school
at Grantham, and was removed thence in his eighteenth year to Trinity
College, Cambridge.
The 5th of June, 1660, was the day of his admission as a sizer into that
distinguished society. He applied himself eagerly to the study of
mathematics, and mastered its difficulties with an ease and rapidity
which he was afterwards inclined almost to regret, from an opinion that
a closer attention to its elementary parts would have improved the
elegance of his own methods of demonstration. In 1664 he became a
scholar of his college, and in 1667 was elected to a fellowship, which
he retained beyond the regular time of its expiration in 1675, by a
special dispensation authorizing him to hold it without taking orders.
It is necessary to return to an earlier date, to trace the series of
Newton’s discoveries. This is not the occasion for a minute enumeration
of them, or for any elaborate discussion of their value or explanation
of their principles; but their history and succession require some
notice. The earliest appear to have related to pure mathematics. The
study of Dr. Wallis’s works led him to investigate certain properties of
series, and this course of research soon conducted him to the celebrated
Binomial Theorem. The exact date of his invention of the method of
Fluxions is not known; but it was anterior to 1666, when the breaking
out of the plague obliged him for a time to quit Cambridge, and
consequently when he was only about twenty-three years old.
This change of residence interrupted his optical researches, in which he
had already laid the foundation of his great discoveries. He had
decomposed light into the coloured rays of which it is compounded, and
having thus ascertained the principal cause of the confusion of the
images formed by refraction, he had turned his attention to the
construction of telescopes which should act by reflection, and be free
from this evil. He had not, however, overcome the practical difficulties
of his undertaking, when his retreat from Cambridge for a time stopped
this train of experiment and invention.
On quitting Cambridge Newton retired to Woolsthorpe, where his mind was
principally employed upon the system of the world. The theory of
Copernicus and the discoveries of Galileo and Kepler had at length
furnished the materials from which the true system was to be deduced. It
was indeed all involved in Kepler’s celebrated laws. The equable
description of areas proved the existence of a central force; the
elliptical form of the planetary orbits, and the relation between their
magnitude and the time occupied in describing them, ascertained the law
of its variation. But no one had arisen to demonstrate these necessary
consequences, or even to conjecture the universal principle from which
they were derived. The existence of a central force had been surmised,
and the law of its action guessed at; but no proof had been given of
either, and little attention had been awakened by the conjecture.
Newton’s discovery appears to have been quite independent of any
speculations of his predecessors. The circumstances attending it are
well known: the very spot in which it first dawned upon him is
ascertained. He was sitting in the garden at Woolsthorpe, when the fall
of an apple called his attention to the force which caused its descent,
to the probable limits of its action and law of its operation. Its power
was not sensibly diminished at any distance at which experiments had
been made: might it not then extend to the moon and guide that luminary
in her orbit? It was certain that her motion was regulated in the same
manner as that of the planets round the sun: if, therefore, the law of
the sun’s action could be ascertained, that by which the earth acted
would also be found by analogy. Newton, therefore, proceeded to
ascertain by calculation from the known elements of the planetary
orbits, the law of the sun’s action. The great experiment remained: the
trial whether the moon’s motions showed the force acting upon her to
correspond with the theoretical amount of terrestrial gravity at her
distance. The result was disappointment. The trial was to be made by
ascertaining the exact space by which the earth’s action turned the moon
aside from her course in a given time. This depended on her actual
distance from the earth, which was only known by comparison with the
earth’s diameter. The received estimate of that quantity was very
erroneous; it proceeded on the supposition that a degree of latitude was
only sixty English miles, nearly a seventh part less than its actual
length. The calculation of the moon’s distance and of the space
described by her, gave results involved in the same proportion of error;
and thus the space actually described appeared to be a seventh part less
than that which corresponded to the theory. It was not Newton’s habit to
force the results of experiments into conformity with hypothesis. He
could not, indeed, abandon his leading idea, which rested, in the case
of the planetary motions, on something very nearly amounting to
demonstration. But it seemed that some modification was required before
it could be applied to the moon’s motion, and no satisfactory solution
of the difficulty occurred. The scheme therefore was incomplete, and, in
conformity with his constant habit of producing nothing till it was
fully matured, Newton kept it undivulged for many years.
On his return to Cambridge Newton again applied himself to the
construction of reflecting telescopes, and succeeded in effecting it in
1668. In the following year Dr. Barrow resigned in his favour the
Lucasian professorship of mathematics, which Newton continued to hold
till the year 1703, when Whiston, who had been his deputy from 1699,
succeeded him in the chair. On January 11, 1672, Newton was elected a
Fellow of the Royal Society. He was then best known by the invention of
the reflecting telescope; but immediately on his election he
communicated to the Society the particulars of his theory of light, on
which he had already delivered three courses of lectures at Cambridge,
and they were shortly afterwards published in the Philosophical
Transactions.
It is impossible here to state the various phenomena of light and
colours which were first detected and explained by Newton. They entirely
changed the science of optics, and every advance which has since been
made in it has only added to the importance and confirmed the value of
his observations. The success of the new theory was complete. Newton,
however, was much vexed and harassed by the discussions which it
occasioned. The annoyance which he thus experienced made him even think
of abandoning the pursuit of science, and although it failed to withdraw
him from the studies to which he was devoted, it confirmed him in his
unwillingness to publish their results.
The next few years of Newton’s life were not marked by any remarkable
events. They were passed almost entirely at Cambridge, in the
prosecution of the researches in which he was engaged. The most
important incident was the communication to Oldenburgh, and, through
him, to Leibnitz, that he possessed a method of determining maxima and
minima, of drawing tangents, and performing other difficult mathematical
operations. This was the method of fluxions, but he did not announce its
name or its processes. Leibnitz, in return, explained to him the
principles and processes of the Differential Calculus. This
correspondence took place in the years 1676 and 1677: but the method of
fluxions had been communicated to Barrow and Collins as early as 1669,
in a tract, first printed in 1711, under the title ‘Analysis per
equationes numero terminorum infinitas.’ Newton had indeed intended to
publish his discovery as an introduction to an edition of Kinckhuysen’s
Algebra, which he undertook to prepare in 1672; but the fear of
controversy prevented him, and the method of fluxions was not publicly
announced till the appearance of the Principia in 1687. The edition of
Kinckhuysen’s treatise did not appear; but the same year, 1672, was
marked by Newton’s editing the Geography of Varenius.
In 1679 Newton’s attention was again called to the theory of
gravitation, and by a fuller investigation of the conditions of
elliptical motion, he was confirmed in the opinion that the phenomena of
the planets were referable to an attractive force in the sun, of which
the intensity varied in the inverse proportion of the square of the
distance. The difficulty about the amount of the moon’s motion remained,
but it was shortly to be removed. In 1679 Picard effected a new
measurement of a degree of the earth’s surface, and Newton heard of the
result at a meeting of the Royal Society in June, 1682. He immediately
returned home to repeat his former calculation with these new data.
Every step of the process made it more probable that the discrepance
which had so long perplexed him would wholly disappear: and so great was
his excitement at the prospect of entire success that he was unable to
proceed with the calculation, and intrusted its completion to a friend.
The triumph was perfect, and he found the theory of his youth sufficient
to explain all the great phenomena of nature.
From this time Newton devoted unremitting attention to the development
of his system, and a period of nearly two years was entirely absorbed by
it. In 1684 the outline of the mighty work was finished; yet it is
likely that it would still have remained unknown, had not Halley, who
was himself on the track of some part of the discovery, gone to
Cambridge in August of that year to consult Newton about some
difficulties he had met with. Newton communicated to him a treatise De
Motu Corporum, which afterwards, with some additions, formed the first
two books of the Principia. Even then Halley found it difficult to
persuade him to communicate the treatise to the Royal Society, but he
finally did so in April, 1686, with a desire that it should not
immediately be published, as there were yet many things to complete.
Hooke, whose unwearied ingenuity had guessed at the true law of gravity,
immediately claimed to himself the honour of the discovery; how unjustly
it is needless to say, for the merit consisted not in the conjecture but
the demonstration. Newton was inclined in consequence to prevent the
publication of the work, or at least of the third part, De Mundi
Systemate, in which the mathematical conclusions of the former books
were applied to the system of the universe. Happily his reluctance was
overcome, and the whole work was published in May, 1687. Its doctrines
were too novel and surprising to meet with immediate assent; but the
illustrious author at once received the tribute of admiration for the
boldness which had formed, and the skill which had developed his theory,
and he lived to see it become the common philosophical creed of all
nations.
We next find Newton acting in a very different character. James II. had
insulted the University of Cambridge by a requisition to admit a
Benedictine monk to the degree of Master of Arts without taking the
oaths enjoined by the constitution of the University. The mandate was
disobeyed; and the Vice-Chancellor was summoned before the
Ecclesiastical Commission to answer for the contempt. Nine delegates, of
whom Newton was one, were appointed by the University to defend their
proceedings; and their exertions were successful. He was soon after
elected to the Convention Parliament as member for the University of
Cambridge. That parliament was dissolved in February, 1690, and Newton,
who was not a candidate for a seat in the one which succeeded it,
returned to Cambridge, where he continued to reside for some years,
notwithstanding the efforts of Locke, and some other distinguished
persons with whom he had become acquainted in London, to fix him
permanently in the metropolis.
During this time he continued to be occupied with philosophical
research, and with scientific and literary correspondence. Chemical
investigations appear to have engaged much of his time; but the
principal results of his studies were lost to the world by a fire in his
chambers about the year 1692. The consequences of this accident have
been very differently related. According to one version, a favourite
dog, called Diamond, caused the mischief, and the story has been often
told, that Newton was only provoked, by the loss of the labour of years,
to the exclamation, “Oh, Diamond! Diamond! thou little knowest the
mischief thou hast done.” Another, and probably a better authenticated
account, represents the disappointment as preying deeply on his spirits
for at least a month from the occurrence.
We have more means of tracing Newton’s other pursuits about this time.
History, chronology, and divinity were his favourite relaxations from
science, and his reputation stood high as a proficient in these studies.
In 1690 he communicated to Locke his ‘Historical account of two notable
corruptions of the Scriptures,’ which was first published long after his
death. About the same time he was engaged in those researches which were
afterwards embodied in his Observations on the Prophecies: and in
December, 1692, he was in correspondence with Bentley on the application
of his own system to the support of natural theology.
During the latter part of 1692 and the beginning of 1693 Newton’s health
was considerably impaired, and he laboured in the summer under some
epidemic disorder. It is not likely that the precise character or amount
of his indisposition will ever be discovered; but it seems, though the
opinion has been much controverted, that for a short time it affected
his understanding, and that in September, 1693, he was not in the full
possession of his mental faculties. The disease was soon removed, and
there is no reason to suppose that it ever recurred. But the course of
his life was changed; and from this time forward he devoted himself
chiefly to the completion of his former works, and abstained from any
new career of continued research.
His time indeed was less at his own disposal than it had been. In 1696,
Mr. Montague, the Chancellor of the Exchequer, an early friend of
Newton, appointed him to the Wardenship of the Mint, and in 1699 he was
raised to the office of Master. He removed to London, and was much
occupied, especially during the new coinage in 1696 and 1697, with the
duties of his office. Still he found time to superintend the editions of
his earlier works, which successively appeared with very material
additions and improvements. The great work on Optics appeared for the
first time in a complete form in 1704, after the death of Hooke had
freed Newton from the fear of new controversies. It was accompanied by
some of his earlier mathematical treatises; and contained also, in
addition to the principal subject of the work, suggestions on a variety
of subjects of the highest philosophical interest, embodied in the shape
of queries. Among these is to be found the first suggestion of the
polarity of light; and we may mention at the same time, although they
occur in a different part of the work, the remarkable conjectures, since
verified, of the combustible nature of the diamond, and the existence of
an inflammable principle in water. The second edition of the Principia
appeared under the care of Cotes in 1713, after having been the subject
of correspondence between Newton and his editor for nearly four years.
Dr. Pemberton published a third edition in 1725, and he frequently
communicated about the work with Newton who was then eighty-two years
old.
These were the chief scientific employments of Newton’s latter life: and
it is not necessary to particularize all its minor details. In 1712 he
made some improvements in his Arithmetica Universalis, a work containing
his algebraical discoveries, of which Whiston had surreptitiously
published an edition in 1707. It is also worthy of remark that at the
beginning of the year 1697, John Bernouilli addressed two problems as a
challenge to the mathematicians of Europe, and that Leibnitz in 1716
made a similar appeal to the English analysts; and that Newton in each
case undertook and succeeded in the investigation.
This enumeration of Newton’s philosophical employments has far outrun
the order of time. After his return to London, compliments and honours
flowed in rapidly upon him. In 1699 he was elected one of the first
foreign associates of the Académie des Sciences at Paris; and in 1701 he
was a second time returned to Parliament by the University of Cambridge.
He did not, however, long retain his seat. At the election in 1705 he
was at the bottom of the poll, and he does not appear again to have been
a candidate. In 1703 he was chosen President of the Royal Society, and
held that office till his death. In 1705 he was knighted by Queen Anne
upon her visit to Cambridge.
Newton’s life in London was one of much dignity and comfort. He was
courted by the distinguished of all ranks, and particularly by the
Princess of Wales, who derived much pleasure from her intercourse both
with him and Leibnitz. His domestic establishment was liberal, and was
superintended during great part of his time by his niece, Mrs. Barton, a
woman of much beauty and talent, who married Mr. Conduitt, his assistant
and successor at the Mint. Newton’s liberality was almost boundless, yet
he died rich.
The only material drawback to Newton’s enjoyment during this portion of
his life, seems to have arisen from controversies as to the history and
originality of his discoveries; a molestation to which his slowness to
publish them very naturally exposed him. There was a long and angry
dispute with Leibnitz about the priority of fluxions or the differential
calculus; and, after the fashion of most disputes, it diverged widely
from the original ground, and it became necessary for Newton to
vindicate the religious and metaphysical tendencies of his greatest
works. His success was complete on all points. Leibnitz does not appear
to have been acquainted with the method of fluxions at the time of his
own discovery, but there is now no doubt of Newton’s having preceded him
by some years; and the attacks made on the tendency of Newton’s
discoveries have long been remembered only as disgracing their author.
But such discussions had always been distasteful to Newton, and this
controversy, which was conducted with great rancour by his opponents and
some of his supporters, embittered his later years.
The same fate awaited him in another instance. His system of Chronology
had been long conceived, but he had not communicated it to any one until
he explained it to the Princess of Wales. At her desire, he afterwards,
in 1718, drew up a short abstract of it for her use, and sent it to her
on condition that no one else should see it. She afterwards requested
that the Abbé Conti might have a copy of it, and Newton complied, but
still on the terms that it should not be farther divulged. Conti,
however, showed the manuscript at Paris to Freret, who, without the
author’s permission, translated and published it with observations in
opposition to its doctrines. Newton drew up a reply which was printed in
the Philosophical Transactions for 1725, and this was the signal for a
new attack by Souciet. Newton was then roused to his last great
exertion, that of fully digesting his system; which as yet existed only
in confused papers, and preparing it for the press. He did not live to
complete his task, but the work was left in a state of great
forwardness, and was published in 1728 by Mr. Conduitt. Its value is
well known. As a refutation of the systems of chronology then received,
it is almost demonstrative; and the affirmative conclusions, if not
always minutely correct, or even generally satisfactory, are yet among
the most valuable contributions which science has made to history.
With the exception of the attack of 1693, Newton’s health had usually
been very good. But he suffered much from stone during the last few
years of his life. His mental faculties remained in general unaffected,
but his memory was much impaired. From the year 1725 he lived at
Kensington, but was still fond of going occasionally to London, and
visited it on February 28th, 1727, to preside at a meeting of the Royal
Society. The fatigue appears to have been too great: for the disease
attacked him violently on the 4th of March, and he lingered till the
20th, when he died. His sufferings were severe, but his temper was never
soured, nor the benevolence of his nature obscured. Indeed his moral was
not less admirable than his intellectual character, and it was guided
and supported by that religion, which he had studied not from
speculative curiosity, but with the serious application of a mind
habitually occupied with its duties, and earnestly desirous of its
advancement.
Newton died without a will, and his property descended to Mrs. Conduitt
and his other relations in the same degree. He was buried with great
pomp in Westminster Abbey, where there is a monument to his memory,
erected by his relations. His Chronology appeared, as has been already
mentioned, almost immediately after his death; and the Lectiones Opticæ,
the substance of his lectures at Cambridge in the years 1669, 1670, and
1671, were published from his manuscripts in 1729. In 1733, Mr. Benjamin
Smith, one of the descendants of his mother’s second marriage, published
the Observations on the Prophecies. These, in addition to the works
already mentioned, are Newton’s principal writings; there are, however,
several smaller tracts, some of which appeared during his lifetime, and
some after his death, which it is not necessary here to specify. They
would have conferred much honour on most philosophers;—they are hardly
remembered in reckoning up Newton’s titles to fame.
[Illustration: Roubiliac’s Statue from the Chapel of Trinity College.]
Many portraits of Newton are in existence. The Royal Society possesses
two; and Lord Egremont is the owner of one, which is engraved as the
frontispiece to Dr. Brewster’s Life of Newton. Trinity College,
Cambridge, abounds in memorials of its greatest ornament. Almost every
room dedicated to public purposes possesses a picture of him, and the
chapel is adorned by Roubiliac’s noble statue. The library also has a
bust by the same artist, of perhaps even superior excellence. As works
of art these are far superior to any of the paintings extant: but they
have not the claim to authenticity possessed by the contemporary
portraits. It is remarkable, that until the recent publication of Dr.
Brewster’s life, no one had thought it worth while to devote an entire
work to the history of so remarkable a man as Newton. There is, however,
an elaborate memoir of him, written by M. Biot, in the Biographie
Universelle, which has been republished in the Library of Useful
Knowledge.
[Illustration:
_Engraved by R. Woodman._