Great Astronomers by Robert Stawell Ball (uplifting novels .txt) ๐
Ptolemy commences with laying down the undoubted truth that the shape of the earth is globular. The proofs which he gives of this fundamental fact are quite satisfactory; they are indeed the same proofs as we give today. There is, first of all, the well-known circumstance of which our books on geography remind us, that when an object is viewed at a distance across the sea, the lower part of the object appears cut off by the interposing curved mass of water.
The sagacity of Ptolemy enabled him to adduce another argument, which, though not quite so obvious as that just mentioned, demonstrates the curvature of the earth in a very impressive manner to anyone who will take the trouble to understand it. Ptolemy mentions that travellers who went to the south
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Woolsthorpe, she entrusted little Isaac to her mother, Mrs.
Ayscough. In due time we find that the boy was sent to the public
school at Grantham, the name of the master being Stokes. For the
purpose of being near his work, the embryo philosopher was boarded
at the house of Mr. Clark, an apothecary at Grantham. We learn
from Newton himself that at first he had a very low place in the
class lists of the school, and was by no means one of those model
schoolboys who find favour in the eyes of the school-master by
attention to Latin grammar. Isaacโs first incentive to diligent
study seems to have been derived from the circumstance that he was
severely kicked by one of the boys who was above him in the class.
This indignity had the effect of stimulating young Newtonโs
activity to such an extent that he not only attained the desired
object of passing over the head of the boy who had maltreated him,
but continued to rise until he became the head of the school.
The play-hours of the great philosopher were devoted to pursuits
very different from those of most schoolboys. His chief
amusement was found in making mechanical toys and various
ingenious contrivances. He watched day by day with great interest
the workmen engaged in constructing a windmill in the
neighbourhood of the school, the result of which was that the boy
made a working model of the windmill and of its machinery, which
seems to have been much admired, as indicating his aptitude for
mechanics. We are told that Isaac also indulged in somewhat
higher flights of mechanical enterprise. He constructed a
carriage, the wheels of which were to be driven by the hands of
the occupant, while the first philosophical instrument he made
was a clock, which was actuated by water. He also devoted much
attention to the construction of paper kites, and his skill in
this respect was highly appreciated by his schoolfellows. Like a
true philosopher, even at this stage he experimented on the best
methods of attaching the string, and on the proportions which the
tail ought to have. He also made lanthorns of paper to provide
himself with light as he walked to school in the dark winter
mornings.
The only love affair in Newtonโs life appears to have commenced
while he was still of tender years. The incidents are thus
described in Brewsterโs โLife of Newton,โ a work to which I am
much indebted in this chapter.
โIn the house where he lodged there were some female inmates, in
whose company he appears to have taken much pleasure. One of these,
a Miss Storey, sister to Dr. Storey, a physician at Buckminster,
near Colsterworth, was two or three years younger than Newton and
to great personal attractions she seems to have added more than
the usual allotment of female talent. The society of this young
lady and her companions was always preferred to that of his own
schoolfellows, and it was one of his most agreeable occupations
to construct for them little tables and cupboards, and other
utensils for holding their dolls and their trinkets. He had lived
nearly six years in the same house with Miss Storey, and there is
reason to believe that their youthful friendship gradually rose to
a higher passion; but the smallness of her portion, and the
inadequacy of his own fortune, appear to have prevented the
consummation of their happiness. Miss Storey was afterwards twice
married, and under the name of Mrs. Vincent, Dr. Stukeley visited
her at Grantham in 1727, at the age of eighty-two, and obtained
from her many particulars respecting the early history of
our author. Newtonโs esteem for her continued unabated during
his life. He regularly visited her when he went to Lincolnshire,
and never failed to relieve her from little pecuniary difficulties
which seem to have beset her family.โ
The schoolboy at Grantham was only fourteen years of age when his
mother became a widow for the second time. She then returned to
the old family home at Woolsthorpe, bringing with her the three
children of her second marriage. Her means appear to have been
somewhat scanty, and it was consequently thought necessary to
recall Isaac from the school. His recently-born industry had been
such that he had already made good progress in his studies, and
his mother hoped that he would now lay aside his books, and those
silent meditations to which, even at this early age, he had become
addicted. It was expected that, instead of such pursuits, which
were deemed quite useless, the boy would enter busily into the
duties of the farm and the details of a country life. But before
long it became manifest that the study of nature and the pursuit
of knowledge had such a fascination for the youth that he could
give little attention to aught else. It was plain that he would
make but an indifferent farmer. He greatly preferred
experimenting on his water-wheels to looking after labourers,
while he found that working at mathematics behind a hedge was much
more interesting than chaffering about the price of bullocks in
the market place. Fortunately for humanity his mother, like a
wise woman, determined to let her boyโs genius have the scope
which it required. He was accordingly sent back to Grantham
school, with the object of being trained in the knowledge which
would fit him for entering the University of Cambridge.
[PLATE: TRINITY COLLEGE, CAMBRIDGE.
Showing Newtonโs rooms; on the leads of the gateway he placed
his telescope.]
It was the 5th of June, 1660, when Isaac Newton, a youth of
eighteen, was enrolled as an undergraduate of Trinity College,
Cambridge. Little did those who sent him there dream that this
boy was destined to be the most illustrious student who ever
entered the portals of that great seat of learning. Little could
the youth himself have foreseen that the rooms near the gateway
which he occupied would acquire a celebrity from the fact that he
dwelt in them, or that the ante-chapel of his college was in good
time to be adorned by that noble statue, which is regarded as one
of the chief art treasures of Cambridge University, both on
account of its intrinsic beauty and the fact that it commemorates
the fame of her most distinguished alumnus, Isaac Newton, the
immortal astronomer. Indeed, his advent at the University seemed
to have been by no means auspicious or brilliant. His birth was,
as we have seen, comparatively obscure, and though he had already
given indication of his capacity for reflecting on philosophical
matters, yet he seems to have been but ill-equipped with the
routine knowledge which youths are generally expected to take with
them to the Universities.
From the outset of his college career, Newtonโs attention seems to
have been mainly directed to mathematics. Here he began to give
evidence of that marvellous insight into the deep secrets of
nature which more than a century later led so dispassionate a
judge as Laplace to pronounce Newtonโs immortal work as
pre-eminent above all the productions of the human intellect.
But though Newton was one of the very greatest mathematicians
that ever lived, he was never a mathematician for the mere sake
of mathematics. He employed his mathematics as an instrument for
discovering the laws of nature. His industry and genius soon
brought him under the notice of the University authorities.
It is stated in the University records that he obtained a
Scholarship in 1664. Two years later we find that Newton, as well
as many residents in the University, had to leave Cambridge
temporarily on account of the breaking out of the plague.
The philosopher retired for a season to his old home at
Woolsthorpe, and there he remained until he was appointed a Fellow
of Trinity College, Cambridge, in 1667. From this time onwards,
Newtonโs reputation as a mathematician and as a natural philosopher
steadily advanced, so that in 1669, while still but twenty-seven
years of age, he was appointed to the distinguished position of
Lucasian Professor of Mathematics at Cambridge. Here he found the
opportunity to continue and develop that marvellous career of
discovery which formed his lifeโs work.
The earliest of Newtonโs great achievements in natural philosophy
was his detection of the composite character of light. That a
beam of ordinary sunlight is, in fact, a mixture of a very great
number of different-coloured lights, is a doctrine now familiar
to every one who has the slightest education in physical science.
We must, however, remember that this discovery was really a
tremendous advance in knowledge at the time when Newton announced
it.
[PLATE: DIAGRAM OF A SUNBEAM.]
We here give the little diagram originally drawn by Newton, to
explain the experiment by which he first learned the composition
of light. A sunbeam is admitted into a darkened room through an
opening, H, in a shutter. This beam when not interfered with will
travel in a straight line to the screen, and there reproduce a
bright spot of the same shape as the hole in the shutter.
If, however, a prism of glass, A B C, be introduced so that the
beam traverse it, then it will be seen at once that the light is
deflected from its original track. There is, however, a further
and most important change which takes place. The spot of light is
not alone removed to another part of the screen, but it becomes
spread out into a long band beautifully coloured, and exhibiting
the hues of the rainbow. At the top are the violet rays, and then
in descending order we have the indigo, blue, green, yellow,
orange, and red.
The circumstance in this phenomenon which appears to have
particularly arrested Newtonโs attention, was the elongation
which the luminous spot underwent in consequence of its passage
through the prism. When the prism was absent the spot was nearly
circular, but when the prism was introduced the spot was about
five times as long as it was broad. To ascertain the explanation
of this was the first problem to be solved. It seemed natural to
suppose that it might be due to the thickness of the glass in the
prism which the light traversed, or to the angle of incidence at
which the light fell upon the prism. He found, however, upon
careful trial, that the phenomenon could not be thus accounted
for. It was not until after much patient labour that the true
explanation dawned upon him. He discovered that though the beam
of white light looks so pure and so simple, yet in reality it is
composed of differently coloured lights blended together. These
are, of course, indistinguishable in the compound beam, but they
are separated or disentangled, so to speak, by the action of the
prism. The rays at the blue end of the spectrum are more
powerfully deflected by the action of the glass than are the rays
at the red end. Thus, the rays variously coloured red, orange,
yellow, green, blue, indigo, violet, are each conducted to a
different part of the screen. In this way the prism has the
effect of exhibiting the constitution of the composite beam of
light.
To us this now seems quite obvious, but Newton did not adopt it
hastily. With characteristic caution he verified the explanation
by many different experiments, all of which confirmed his
discovery. One of these may be mentioned. He made a hole in the
screen at that part on which the violet rays fell. Thus a violet
ray was allowed to pass through, all the rest of the light being
intercepted, and on this beam so isolated he was able to try
further experiments. For instance, when he interposed another
prism in its path, he found, as he expected, that it was again
deflected,
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