Daily globe., 1879-06-01
New Planets Near the Sun.

Perhaps no scientific achievement dur
ing the present century has been deemed
more marvellous than the discovery of the
outermost member $50 far as is knewn)
of the suns family Of planets. In many
respects, apart from the great difficulty
Of the mathematical problem involved,
the discovery appealed strongly to the
imagination. A planet seventeen hun
dred millions of miles from the sun had
been discovered in March, 1871, by a
mere accident, though the accident was
not one likely to occur to any one but an
astronomer constantly studying the star
depths. Engaged in such observation,
but with no idea of enlarging the known
domain Of the sun, Sir W. Herschel per-
ceived the distant planet Uranus. His
experienced eye at once recognized the
fact that the starnger was not fixed
star. He judged it to be comet. Itwas
not until several weeks had elapsed that
the newly discovered body was proved to
be planet, travelling nearly twice as far
away from the sun s Saturn, the remot-
est planet before known. A century on
" had elapsed since the theory of gravi-
tation had been established. Yet it was
once perceived how greatly this theory
had increased the power of the astrono-
mer to deal with planatory motions
Before a year had passed more was
known about the motions of Uranus than
! had been learned about the motion of any
of the cd planets during 1900 years pre-
ceding the time of Copernicus. It was
possible to calculate in advance the
position Of the newly discovered planet, to
calculate retrogressively the path along
which it had been travelling, unseen and
unsuspected, during the century preced-
ing its discovery. And now observations
which many might have judged to be of
little value came in most usefully. As
tromers since the discovery Of the teles-
cope had formed catalogues of the places
of many hundreds of stars invisible tc
the naked eye. Search among the obser.
vations by which such catalogues had
been formed revealed the fact that Uran.
us had been seen and catalogued as fix.
ed star 81 several times! Flamsteed had
seen it five times, each time recording il
as star of the sixth magnitude, SO that
five of Flamsteed's stars had to be can
celed from his lists, Lemonnier had act
ually seen Uranus 10 times, and only es
capped the honor Of discovering the plane
Gas such) through the most marvellous
carelessness, his astronomical papers be
ing, as Arago said, ga very picture o
chaos" Bradley saw Uranus three times
Mayer saw the planet once only. It wa
from the study Of the movement Of Uran
us as thus seen, combined with the plan
cts progress after its discovery, tina
mathematicians first began to supect thu
existence of some unknown disturbing
body. The observations preceding th'
discovery Of the planet range over an in
terval of 80 years and few months, tn,
earliest observation used being one
made by Flamsteed Dec. %, 1890. Ther,
is something very strange in the though
that science was able thus to deal will
the motions of a planet for nearly a cen
tury before the planet was known. As
tronomy calulated in the first place wher
the planet had been during that time
} and then, from records made by departed
observers, who had no suspicion of tn
real nature Of the body they were observ
ing, astronomy corrected her calculation
and deduced more vigorously the tru
nature of the new planets motions.