gave the explanation of the tides that ebb and flow around our
shores. Even in the earliest times the tides had been shown to be
related to the moon. It was noticed that the tides were specially
high during full moon or during new moon, and this circumstance
obviously pointed to the existence of some connection between the
moon and these movements of the water, though as to what that
connection was no one had any accurate conception until Newton
announced the law of gravitation. Newton then made it plain that the
rise and fall of the water was simply a consequence of the attractive
power which the moon exerted upon the oceans lying upon our globe. He
showed also that to a certain extent the sun produces tides, and he
was able to explain how it was that when the sun and the moon both
conspire, the joint result was to produce especially high tides,
which we call "spring tides"; whereas if the solar tide was low,
while the lunar tide was high, then we had the phenomenon of "neap"
tides.
But perhaps the most signal of Newton's applications of the law of
gravitation was connected with certain irregularities in the
movements of the moon. In its orbit round the earth our satellite
is, of course, mainly guided by the great attraction of our globe. If
there were no other body in the universe, then the centre of the moon
must necessarily perform an ellipse, and the centre of the earth
would lie in the focus of that ellipse. Nature, however, does not
allow the movements to possess the simplicity which this arrangement
would imply, for the sun is present as a source of disturbance. The
sun attracts the moon, and the sun attracts the earth, but in
different degrees, and the consequence is that the moon's movement
with regard to the earth is seriously affected by the influence of
the sun. It is not allowed to move exactly in an ellipse, nor is the
earth exactly in the focus. How great was Newton's achievement in
the solution of this problem will be appreciated if we realise that
he not only had to determine from the law of gravitation the nature
of the disturbance of the moon, but he had actually to construct the
mathematical tools by which alone such calculations could be
effected.
The resources of Newton's genius seemed, however, to prove equal to
almost any demand that could be made upon it. He saw that each
planet must disturb the other, and in that way he was able to render
a satisfactory account of certain phenomena which had perplexed all
preceding investigators. That mysterious movement by which the pole
of the earth sways about among the stars had been long an unsolved
enigma, but Newton showed that the moon grasped with its attraction
the protuberant mass at the equatorial regions of the earth, and thus
tilted the earth's axis in a way that accounted for the phenomenon
which had been known but had never been explained for two thousand
years. All these discoveries were brought together in that immortal
work, Newton's "Principia."
Down to the year 1687, when the "Principia" was published, Newton had
lived the life of a recluse at Cambridge, being entirely occupied
with those transcendent researches to which we have referred. But in
that year he issued from his seclusion under circumstances of
considerable historical interest. King James the Second attempted an
invasion of the rights and privileges of the University of Cambridge
by issuing a command that Father Francis, a Benedictine monk, should
be received as a Master of Arts in the University, without having taken
the oaths of allegiance and supremacy. With this arbitrary command
the University sternly refused to comply. The Vice-Chancellor was
accordingly summoned to answer for an act of contempt to the authority
of the Crown. Newton was one of nine delegates who were chosen to
defend the independence of the University before the High Court.
They were able to show that Charles the Second, who had issued a
MANDAMUS under somewhat similar circumstances, had been induced after
due consideration to withdraw it. This argument appeared satisfactory,
and the University gained their case. Newton's next step in public
life was his election, by a narrow majority, as member for the
University, and during the years 1688 and 1689, he seems to have
attended to his parliamentary duties with considerable regularity.
An incident which happened in 1692 was apparently the cause of
considerable disturbance in Newton's equanimity, if not in his
health. He had gone to early morning chapel, leaving a lighted
candle among his papers on his desk. Tradition asserts that his
little dog "Diamond" upset the candle; at all events, when Newton
came back he found that many valuable papers had perished in a
conflagration. The loss of these manuscripts seems to have had a
serious effect. Indeed, it has been asserted that the distress
reduced Newton to a state of mental aberration for a considerable
time. This has, apparently, not been confirmed, but there is no
doubt that he experienced considerable disquiet, for in writing on
September 13th, 1693, to Mr. Pepys, he says:
"I am extremely troubled at the embroilment I am in, and have
neither ate nor slept well this twelve-month, nor have my former
consistency of mind."
Notwithstanding the fame which Newton had achieved, by the
publication of his, "Principia," and by all his researches, the State
had not as yet taken any notice whatever of the most illustrious man
of science that this or any other country has ever produced. Many of
his friends had exerted themselves to procure him some permanent
appointment, but without success. It happened, however, that Mr.
Montagu, who had sat with Newton in Parliament, was appointed
Chancellor of the Exchequer in 1694. Ambitious of distinction in his
new office, Mr. Montagu addressed himself to the improvement of the
current coin, which was then in a very debased condition. It
fortunately happened that an opportunity occurred of appointing a new
official in the Mint; and Mr. Montagu on the 19th of March, 1695,
wrote to offer Mr. Newton the position of warden. The salary was to
be five or six hundred a year, and the business would not require
more attendance than Newton could spare. The Lucasian professor
accepted this post, and forthwith entered upon his new duties.
The knowledge of physics which Newton had acquired by his experiments
was of much use in connection with his duties at the Mint. He
carried out the re-coinage with great skill in the course of two
years, and as a reward for his exertions, he was appointed, in 1697,
to the Mastership of the Mint, with a salary between 1,200 Pounds and
1,500 Pounds per annum. In 1701, his duties at the Mint being so
engrossing, he resigned his Lucasian professorship at Cambridge, and
at the same time he had to surrender his fellowship at Trinity
College. This closed his connection with the University of
Cambridge. It should, however, be remarked that at a somewhat
earlier stage in his career he was very nearly being appointed to an
office which might have enabled the University to retain the great
philosopher within its precincts. Some of his friends had almost
succeeded in securing his nomination to the Provostship of King's
College, Cambridge; the appointment, however, fell through, inasmuch
as the statute could not be evaded, which required that the Provost
of King's College should be in holy orders.
In those days it was often the custom for illustrious mathematicians,
when they had discovered a solution for some new and striking
problem, to publish that problem as a challenge to the world, while
withholding their own solution. A famous instance of this is found
in what is known as the Brachistochrone problem, which was solved by
John Bernouilli. The nature of this problem may be mentioned. It
was to find the shape of the curve along which a body would slide
down from one point (A) to another point (B) in the shortest time. It
might at first be thought that the straight line from A to B, as it
is undoubtedly the shortest distance between the points, would also
be the path of quickest descent; but this is not so. There is a
curved line, down which a bead, let us say, would run on a smooth
wire from A to B in a shorter time than the same bead would require
to run down the straight wire. Bernouilli's problem was to find out
what that curve must be. Newton solved it correctly; he showed that
the curve was a part of what is termed a cycloid--that is to say, a
curve like that which is described by a point on the rim of a
carriage-wheel as the wheel runs along the ground. Such was Newton's
geometrical insight that he was able to transmit a solution of the
problem on the day after he had received it, to the President of the
Royal Society.
In 1703 Newton, whose world wide fame was now established, was
elected President of the Royal Society. Year after year he was
re-elected to this distinguished position, and his tenure, which
lasted twenty-five years, only terminated with his life. It was in
discharge of his duties as President of the Royal Society that Newton
was brought into contact with Prince George of Denmark. In April,
1705, the Queen paid a visit to Cambridge as the guest of Dr.
Bentley, the then Master of Trinity, and in a court held at Trinity
Lodge on April 15th, 1705, the honour of knighthood was conferred
upon the discoverer of gravitation.
Urged by illustrious friends, who sought the promotion of knowledge,
Newton gave his attention to the publication of a new edition of the
"Principia." His duties at the Mint, however, added to the supreme
duty of carrying on his original investigations, left him but little
time for the more ordinary task of the revision. He was accordingly
induced to associate with himself for this purpose a distinguished
young mathematician, Roger Coates, a Fellow of Trinity College,
Cambridge, who had recently been appointed Plumian Professor of
Astronomy. On July 27th, 1713, Newton, by this time a favourite at
Court, waited on the Queen, and presented her with a copy of the new
edition of the "Principia."
Throughout his life Newton appears to have been greatly interested in
theological studies, and he specially devoted his attention to the
subject of prophecy. He left behind him a manuscript on the
prophecies of Daniel and the Apocalypse of St. John, and he also
wrote various theological papers. Many other subjects had from time
to time engaged his attention. He studied the laws of heat; he
experimented in pursuit of the dreams of the Alchymist; while the
philosopher who had revealed the mechanism of the heavens found
occasional relaxation in trying to interpret hieroglyphics. In the
last few years of his life he bore with fortitude a painful ailment,
and on Monday, March 20th, 1727, he died in the eighty-fifth year of
his age. On Tuesday, March 28th, he was buried in Westminster Abbey.
Though Newton lived long enough to receive the honour that his
astonishing discoveries so justly merited, and though for many years
of his life his renown was much greater than that of any of his
contemporaries, yet it is not too much to say that, in the years
which have since elapsed, Newton's fame has been ever steadily
advancing, so that it never stood higher than it does at this moment.
We hardly know whether to admire more the sublime discoveries at
which he arrived, or the extraordinary character of the intellectual
processes by which those discoveries were reached. Viewed from
either standpoint, Newton's "Principia" is incomparably the greatest
work on science that has ever yet been produced.
[PLATE: SIR ISAAC NEWTON'S SUN-DIAL IN THE ROYAL SOCIETY.]
FLAMSTEED.
Among the manuscripts preserved at Greenwich Observatory are certain
documents in which Flamsteed gives an account of his own life. We
may commence our sketch by quoting the following passage from this
autobiography:--"To keep myself from idleness, and to recreate
myself, I have intended here to give some account of my life, in my
youth, before the actions thereof, and the providences of God
therein, be too far passed out of my memory; and to observe the
accidents of all my years, and inclinations of my mind, that
whosoever may light upon these papers may see I was not so wholly
taken up, either with my father's business or my mathematics, but
that I both admitted and found time for other as weighty
considerations."
The chief interest which attaches to the name of Flamsteed arises
from the fact that he was the first of the illustrious series of
Astronomers Royal who have presided over Greenwich Observatory. In
that capacity Flamsteed was able to render material assistance to
Newton by providing him with the observations which his lunar theory
required.
John Flamsteed was born at Denby, in Derbyshire, on the 19th of
August, 1646. His mother died when he was three years old, and the
second wife, whom his father took three years later, only lived until
Flamsteed was eight, there being also two younger sisters. In his
boyhood the future astronomer tells us that he was very fond of those
romances which affect boy's imagination, but as he writes, "At twelve
years of age I left all the wild ones and betook myself to read the
better sort of them, which, though they were not probable, yet
carried no seeming impossibility in the picturing." By the time
Flamsteed was fifteen years old he had embarked in still more serious
work, for he had read Plutarch's "Lives," Tacitus' "Roman History,"
and many other books of a similar description. In 1661 he became ill
with some serious rheumatic affection, which obliged him to be
withdrawn from school. It was then for the first time that he
received the rudiments of a scientific education. He had, however,
attained his sixteenth year before he made any progress in
arithmetic. He tells us how his father taught him "the doctrine of
fractions," and "the golden rule of three"--lessons which he seemed
to have learned easily and quickly. One of the books which he read
at this time directed his attention to astronomical instruments, and
he was thus led to construct for himself a quadrant, by which he
could take some simple astronomical observations. He further
calculated a table to give the sun's altitudes at different hours,
and thus displayed those tastes for practical astronomy which he
lived to develop so greatly. It appears that these scientific
studies were discountenanced by his father, who designed that his son
should follow a business career. Flamsteed's natural inclination,
however, forced him to prosecute astronomical work, notwithstanding
the impediments that lay in his path. Unfortunately, his
constitutional delicacy seems to have increased, and he had just
completed his eighteenth year, "when," to use his own words, "the
winter came on and thrust me again into the chimney, whence the heat
and the dryness of the preceding summer had happily once before
withdrawn me. But, it not being a fit season for physic, it was
thought fit to let me alone this winter, and try the skill of another
physician on me in the spring."
It appears that at this time a quack named Valentine Greatrackes, was
reputed to have effected most astonishing cures in Ireland merely by
the stroke of his hands, without the application of any medicine
whatever. Flamsteed's father, despairing of any remedy for his son
from the legitimate branch of the profession, despatched him to
Ireland on August 26th, 1665, he being then, as recorded with
astronomical accuracy, "nineteen years, six days, and eleven hours
old." The young astronomer, accompanied by a friend, arrived on a
Tuesday at Liverpool but the wind not being favourable, they remained
there till the following Friday, when a shift of the wind to the east
took place. They embarked accordingly on a vessel called the SUPPLY
at noon, and on Saturday night came in sight of Dublin. Ere they
could land, however, they were nearly being wrecked on Lambay
Island. This peril safely passed, there was a long delay for
quarantine before they were at last allowed on shore. On Thursday,
September 6th, they set out from Dublin, where they had been
sojourning at the "Ship" Hotel, in Dame Street, towards Assaune,
where Greatrackes received his patients.
[PLATE: FLAMSTEED'S HOUSE.]
Flamsteed gives an interesting account of his travels in Ireland.
They dined at Naas on the first day, and on September 8th they
reached Carlow, a town which is described as one of the fairest they
saw on their journey. By Sunday morning, September 10th, having lost
their way several times, they reached Castleton, called commonly Four
Mile Waters. Flamsteed inquired of the host in the inn where they
might find a church, but was told that the minister lived twelve
miles away, and that they had no sermon except when he came to
receive his tithes once a year, and a woman added that "they had
plenty enough of everything necessary except the word of God." The
travellers accordingly went on to Cappoquin, which lies up the river
Blackwater, on the road to Lismore, eight miles from Youghal. Thence
they immediately started on foot to Assaune. About a mile from
Cappoquin, and entering into the house of Mr. Greatrackes, they saw
him touch several patients, "whereof some were nearly cured, others
were on the mending hand, and some on whom his strokes had no
effect." Flamsteed was touched by the famous quack on the afternoon
of September 11th, but we are hardly surprised to hear his remark
that "he found not his disease to stir." Next morning the astronomer
came again to see Mr. Greatrackes, who had "a kind of majestical yet
affable presence, and a composed carriage." Even after the third
touching had been submitted to, no benefit seems to have been
derived. We must, however record, to the credit of Mr. Greatrackes,
that he refused to accept any payment from Flamsteed, because he was
a stranger.
Finding it useless to protract his stay any longer, Flamsteed and his
friend set out on their return to Dublin. In the course of his
journey he seems to have been much impressed with Clonmel, which he
describes as an "exceedingly pleasantly seated town." But in those
days a journey to Ireland was so serious an enterprise that when
Flamsteed did arrive safely back at Derby after an absence of a
month, he adds, "For God's providence in this journey, His name be
praised, Amen."
As to the expected benefits to his health from the expedition we may
quote his own words: "In the winter following I was indifferent
hearty, and my disease was not so violent as it used to be at that
time formerly. But whether through God's mercy I received this
through Mr. Greatrackes' touch, or my journey and vomiting at sea, I
am uncertain; but, by some circumstances, I guess that I received a
benefit from both."
It is evident that by this time Flamsteed's interest in all
astronomical matters had greatly increased. He studied the
construction of sun-dials, he formed a catalogue of seventy of the
fixed stars, with their places on the heavens, and he computed the
circumstances of the solar eclipse which was to happen on June 22nd,
1666. It is interesting to note that even in those days the
doctrines of the astrologers still found a considerable degree of
credence, and Flamsteed spent a good deal of his time in astrological
studies and computations. He investigated the methods of casting a
nativity, but a suspicion, or, indeed, rather more than a suspicion,
seems to have crossed his mind as to the value of these astrological
predictions, for he says in fine, "I found astrology to give
generally strong conjectural hints, not perfect declarations."
All this time, however, the future Astronomer Royal was steadily
advancing in astronomical inquiries of a recondite nature. He had
investigated the obliquity of the ecliptic with extreme care, so far
as the circumstances of astronomical observation would at that time
permit. He had also sought to discover the sun's distance from the
earth in so far as it could be obtained by determining when the moon
was exactly half illuminated, and he had measured, with much
accuracy, the length of the tropical year. It will thus be seen
that, even at the age of twenty, Flamsteed had made marked progress,
considering how much his time had been interfered with by ill-health.
Other branches of astronomy began also to claim his attention. We
learn that in 1669 and 1670 he compared the planets Jupiter and Mars
with certain fixed stars near which they passed. His instrumental
means, though very imperfect, were still sufficient to enable him to
measure the intervals on the celestial sphere between the planets and
the stars. As the places of the stars were known, Flamsteed was thus
able to obtain the places of the planets. This is substantially the
way in which astronomers of the present day still proceed when they
desire to determine the places of the planets, inasmuch as, directly
or indirectly those places are always obtained relatively to the
fixed stars. By his observations at this early period, Flamsteed
was, it is true, not able to obtain any great degree of accuracy; he
succeeded, however, in proving that the tables by which the places of
the planets were ordinarily given were not to be relied upon.
[PLATE: FLAMSTEED.]
Flamsteed's labours in astronomy and in the allied branches of
science were now becoming generally known, and he gradually came to
correspond with many distinguished men of learning. One of the first
occasions which brought the talents of the young astronomer into fame
was the publication of some calculations concerning certain
astronomical phenomena which were to happen in the year 1670. In the
monthly revolution of the moon its disc passes over those stars which
lie along its track. The disappearance of a star by the
interposition of the moon is called an "occultation." Owing to the
fact that our satellite is comparatively near us, the position which
the moon appears to occupy on the heavens varies from different parts
of the earth, it consequently happens that a star which would be
occulted to an observer in one locality, would often not be occulted
to an observer who was situated elsewhere. Even when an occultation
is visible from both places, the times at which the star disappears
from view will, generally speaking, be different. Much calculation
is therefore necessary to decide the circumstances under which the
occultations of stars may be visible from any particular station.
Having a taste for such computations, Flamsteed calculated the
occultations which were to happen in the year 1670, it being the case
that several remarkable stars would be passed over by the moon during
this year. Of course at the present time, we find such information
duly set forth in the NAUTICAL ALMANAC, but a couple of centuries ago
there was no such source of astronomical knowledge as is now to be
found in that invaluable publication, which astronomers and
navigators know so well. Flamsteed accordingly sent the results of
his work to the President of the Royal Society. The paper which
contained them was received very favourably, and at once brought
Flamsteed into notice among the most eminent members of that
illustrious body, one of whom, Mr. Collins, became through life his
faithful friend and constant correspondent. Flamsteed's father was
naturally gratified with the remarkable notice which his son was
receiving from the great and learned; accordingly he desired him to
go to London, that he might make the personal acquaintance of those
scientific friends whom he had only known by correspondence
previously. Flamsteed was indeed glad to avail himself of this
opportunity. Thus he became acquainted with Dr. Barrow, and
especially with Newton, who was then Lucasian Professor of
Mathematics at Cambridge. It seems to have been in consequence of
this visit to London that Flamsteed entered himself as a member of
Jesus College, Cambridge. We have but little information as to his
University career, but at all events he took his degree of M.A. on
June 5th, 1674.