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of five hundred pounds of money. He gave bricks from Tilbury
Fort, while materials, in the shape of wood, iron, and lead, were
available from a gatehouse demolished in the Tower. The king also
promised whatever further material aid might be shown to be
necessary. The first stone of the Royal Observatory was laid on
August 10th, 1675, and within a few years a building was erected
in which the art of modern practical astronomy was to be created.
Flamsteed strove with extraordinary diligence, and in spite of
many difficulties, to obtain a due provision of astronomical
instruments, and to arrange for the carrying on of his
observations. Notwithstanding the king’s promises, the astronomer
was, however, but scantily provided with means, and he had no
assistants to help him in his work. It follows that all the
observations, as well as the reductions, and, indeed, all the
incidental work of the observatory, had to be carried on by
himself alone. Flamsteed, as we have seen, had, however, many
staunch friends. Sir Jonas Moore in particular at all times
rendered him most valuable assistance, and encouraged him by the
warm sympathy and keen interest which he showed in astronomy. The
work of the first Astronomer Royal was frequently interrupted by
recurrent attacks of the complaints to which we have already
referred. He says himself that “his distempers stick so close
that that he cannot remove them,” and he lost much time by
prostration from headaches, as well as from more serious
affections.
The year 1678 found him in the full tide of work in his
observatory. He was specially engaged on the problem of the
earth’s motion, which he sought to derive from observations of the
sun and of Venus. But this, as well as many other astronomical
researches which he undertook, were only subsidiary to that which
he made the main task of his life, namely, the formation of a
catalogue of fixed stars. At the time when Flamsteed commenced
his career, the only available catalogue of fixed stars was that
of Tycho Brahe. This work had been published at the commencement
of the seventeenth century, and it contained about a thousand
stars. The positions assigned to these stars, though obtained
with wonderful skill, considering the many difficulties under
which Tycho laboured, were quite inaccurate when judged by our
modern standards. Tycho’s instruments were necessarily most
rudely divided, and he had, of course, no telescopes to aid him.
Consequently it was merely by a process of sighting that he could
obtain the places of the stars. It must further be remembered
that Tycho had no clocks, and no micrometers. He had, indeed, but
little correct knowledge of the motions of the heavenly bodies to
guide him. To determine the longitudes of a few principal stars
he conceived the ingenious idea of measuring by day the position
of Venus with respect to the sun, an observation which the
exceptional brightness of this planet rendered possible without
telescopic aid, and then by night he observed the position of
Venus with regard to the stars.
It has been well remarked by Mr. Baily, in his introduction
to the “British Catalogue of Stars,” that “Flamsteed’s
observations, by a fortunate combination of circumstances,
commenced a new and a brilliant era. It happened that, at that
period, the powerful mind of Newton was directed to this subject;
a friendly intercourse then existed between these two
distinguished characters; and thus the first observations that
could lay any claim to accuracy were at once brought in aid of
those deep researches in which our illustrious geometer was then
engaged. The first edition of the `Principia’ bears testimony to
the assistance afforded by Flamsteed to Newton in these inquiries;
although the former considers that the acknowledgment is not so
ample as it ought to have been.”
Although Flamsteed’s observations can hardly be said to possess
the accuracy of those made in more recent times, when instruments
so much superior to his have been available, yet they possess
an interest of a special kind from their very antiquity. This
circumstance renders them of particular importance to the
astronomer, inasmuch as they are calculated to throw light on the
proper motions of the stars. Flamsteed’s work may, indeed, be
regarded as the origin of all subsequent catalogues, and the
nomenclature which he adopted, though in some respects it can
hardly be said to be very defensible, is, nevertheless, that which
has been adopted by all subsequent astronomers. There were also a
great many errors, as might be expected in a work of such extent,
composed almost entirely of numerical detail. Many of these
errors have been corrected by Baily himself, the assiduous editor
of “Flamsteed’s Life and Works,” for Flamsteed was so harassed
from various causes in the latter part of his life, and was so
subject to infirmities all through his career, that he was unable
to revise his computations with the care that would have been
necessary. Indeed, he observed many additional stars which he
never included in the British Catalogue. It is, as Baily well
remarks, “rather a matter of astonishment that he accomplished so
much, considering his slender means, his weak frame, and the
vexations which he constantly experienced.”
Flamsteed had the misfortune, in the latter part of his life, to
become estranged from his most eminent scientific contemporaries.
He had supplied Newton with places of the moon, at the urgent
solicitation of the author of the “Principia,” in order that the
lunar theory should be carefully compared with observation. But
Flamsteed appears to have thought that in Newton’s further request
for similar information, he appeared to be demanding as a right
that which Flamsteed considered he was only called upon to render
as a favour. A considerable dispute grew out of this matter, and
there are many letters and documents, bearing on the difficulties
which subsequently arose, that are not, perhaps, very creditable
to either party.
Notwithstanding his feeble constitution, Flamsteed lived to the
age of seventy-three, his death occurring on the last day of the
year 1719.
HALLEY.
Isaac Newton was just fourteen years of age when the birth of
Edmund Halley, who was destined in after years to become Newton’s
warmly attached friend, and one of his most illustrious scientific
contemporaries, took place. There can be little doubt that the
fame as an astronomer which Halley ultimately acquired, great as
it certainly was, would have been even greater still had it not
been somewhat impaired by the misfortune that he had to shine in
the same sky as that which was illumined by the unparalleled
genius of Newton.
Edmund Halley was born at Haggerston, in the Parish of
St. Leonard’s, Shoreditch, on October 29th, 1656. His father, who
bore the same name as his famous son, was a soap-boiler in
Winchester Street, London, and he had conducted his business with
such success that he accumulated an ample fortune. I have been
unable to obtain more than a very few particulars with respect to
the early life of the future astronomer. It would, however,
appear that from boyhood he showed considerable aptitude for the
acquisition of various kinds of learning, and he also had some
capacity for mechanical invention. Halley seems to have received
a sound education at St. Paul’s School, then under the care of
Dr. Thomas Gale.
Here, the young philosopher rapidly distanced his competitors in
the various branches of ordinary school instruction. His
superiority was, however, most conspicuous in mathematical
studies, and, as a natural development of such tastes, we learn
that by the time he had left school he had already made good
progress in astronomy. At the age of seventeen he was entered as
a commoner at Queen’s College, Oxford, and the reputation that he
brought with him to the University may be inferred from the remark
of the writer of “Athenae Oxonienses,” that Halley came to Oxford
with skill in Latin, Greek, and Hebrew, and such a knowledge of
geometry as to make a complete dial.” Though his studies were
thus of a somewhat multifarious nature, yet it is plain that from
the first his most favourite pursuit was astronomy. His earliest
efforts in practical observation were connected with an eclipse
which he observed from his father’s house in Winchester Street.
It also appears that he had studied theoretical branches of
astronomy so far as to be conversant with the application of
mathematics to somewhat abstruse problems.
Up to the time of Kepler, philosophers had assumed almost as an
axiom that the heavenly bodies must revolve in circles and that
the motion of the planet around the orbit which it described must
be uniform. We have already seen how that great philosopher,
after very persevering labour, succeeded in proving that the
orbits of the planets were not circles, but that they were
ellipses of small eccentricity. Kepler was, however, unable to
shake himself free from the prevailing notion that the angular
motion of the planet ought to be of a uniform character around
some point. He had indeed proved that the motion round the focus
of the ellipse in which the sun lies is not of this description.
One of his most important discoveries even related to the fact
that at some parts of its orbit a planet swings around the sun
with greater angular velocity than at others. But it so happens
that in elliptic tracks which differ but little from circles, as
is the case with all the more important planetary orbits, the
motion round the empty focus of the ellipse is very nearly
uniform. It seemed natural to assume, that this was exactly the
case, in which event each of the two foci of the ellipse would
have had a special significance in relation to the movement of the
planet. The youthful Halley, however, demonstrated that so far as
the empty focus was concerned, the movement of the planet around
it, though so nearly uniform, was still not exactly so, and at the
age of nineteen, he published a treatise on the subject which at
once placed him in the foremost rank amongst theoretical
astronomers.
But Halley had no intention of being merely an astronomer with his
pen. He longed to engage in the practical work of observing. He
saw that the progress of exact astronomy must depend largely on
the determination of the positions of the stars with all
attainable accuracy. He accordingly determined to take up this
branch of work, which had been so successfully initiated by Tycho
Brahe.
At the present day, astronomers of the great national
observatories are assiduously engaged in the determination of the
places of the stars. A knowledge of the exact positions of these
bodies is indeed of the most fundamental importance, not alone
for the purposes of scientific astronomy, but also for navigation
and for extensive operations of surveying in which accuracy is
desired. The fact that Halley determined to concentrate himself
on this work shows clearly the scientific acumen of the young
astronomer.
Halley, however, found that Hevelius, at Dantzig, and Flamsteed,
the Astronomer Royal at Greenwich, were both engaged on
work of this character. He accordingly determined to direct his
energies in a way that he thought would be more useful to
science. He resigned to the two astronomers whom I have named the
investigation of the stars in the northern hemisphere, and he
sought for himself a field hitherto almost entirely unworked. He
determined to go to the southern hemisphere, there to measure and
survey those stars which were invisible in Europe, so that his
work should supplement the labours of the northern astronomers,
and that the joint result of his labours and of theirs might be a
complete survey of the most important stars on the surface of the
heavens.
In these days, after so many ardent students everywhere have
devoted themselves to the study
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