New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1898-04-18
THE VISIBLE HEAVENS.
A GOOD ASTRONOMICAL HANDBOOK.

other eight members Of that lovely sisterhood
lent inspiration only 20 some form Of art Ana
even at the present day the material "ohoers
OF the skies have an exceptional fascination ho'
only for the professional devotees OF Orah'a'
but also for the general public. 1t Is par'icu-
larry happy event. then. when three such SUI
dents and writer's as Miss Clerke. Mr.. fowie'
and Mr.. Gore collaborate In bringing the SUIT!
Of astronomical research up to date.
A large octave volume was devoted pg MISS
Clerke. several years ago. merely 10 d si"eie
century's record: that which began WIN ."
William Hersche,s work She now packs away
in about forty Introductory pages the chlei IN
cidents that mark the development OF stellar
science. from the days of Hipparchus. who. IN
spired by the appearance OF a brilliant ne" star
IN scorpio, 1874 B. c.. made a catalogue OF over
one thousand stars. down to the present oecaue
achievements In celestial photography. Ptoi-
emy the Alexandrian. whose theory OF the uni
verse was accepted for fourteen centuries
PASSED the torch Of knowledge along to the
Arabs: and the Moors brought It into Spain In
A. D. 1910 A new starting point was reached.
however. when Copernicus laid down the doc
&rine that the earth and planets revove about
The sun Kepler quickly followed with three
xreat laws relating to planetary motions, New
ton with his discoveries regarding gravitaton'
and Laplace with his lucid mathematical expo
sition Of celestial mechanics"
Observational astronomy may be said 10 date
from Galileo's use of the telescope In lolo Inc
amount of knowledge in regard to the heavenly
bodies which the world possessed prior 10 tha'
event was Insignificant compared 10 the as
coveries Of the last three centuries
Much Of the material to be found In Mt Fow-
ler.s $50 pages Of "Geometrical Astronomy and
Astronomical Instruments" is familiar 10 the
.tudent Of college text books. 1t is interesting
70 note however, that this writer. VINO Is an
assistant OF Sir Norman Lockyer, frankly recog-
nizes the influence Of an American. professor L.
C. Pickering in introducing to common use the
camera with a prism IN front OF II, piece OF
apparatus greatly In favor with the great Eng
fish spectroscopist just mentioned. MT. Fowier
gives Professor Hale Of Chicago, due credit TOT
devising the spectre heliograph. and briefly no.
tices Professor Langley's original work with the
bolometer The opinion Of Professor Keller that
the forty-!nch refractor in the Yerkes Observa-
tory practically marks the limit Of possible in
etrumental development in that particular line
IS quoted approvngly.
In the third division OF the Appleton volume
Miss Clerke sums up our present knowledge In
regard to the solar system" She accepts as
approximately accurate. the estimate made by
Wilson and Gray that the temperature OF the
suns surface Is 5000 or 5000 degrees c. Young's
notion Of a reversing layer" Of vapor. situated
close TO the luminous cloud sheet around the
sun, and producing the dark lines OF the spec
trum Is regarded having been fully estab-
lished by Mr.. Shackeltons eclipse photographs
Of 1896 Miss Clerke appears to side with Dr.
Higgins as against Professor Campbell. OF the
Lick Observatory, In giving Mars more aoun-
dant atmosphere than our moon Is believed TO
possess. Professor Keeler's demonstration with
the spectroscope in 1893. that Saturn's ring is
made up Of a multitude of tiny objects. probably
meteorites. is among the more recent discoveries
which find place in Miss Clerkes record
Mr. Gore takes us out TO the stars. every one
of which is believed to be sun; many Of them
larger than ours most OF them millions OF times
more distant from the earth. Here indeed. are
countless and impressive marvels; double and
triple stars, revolving about a common centre
variously colored orbs bodies that fuctuate In
brilliancy. clusters containing thousands Of suns
and runaway stars. Sirius. though the bright
est Of all the heavenly bodies outside Of our
solar system is thought to be only three and
half times big as our sun. Arcturus. there
Is reason to believe is the largest sphere of the
whole celestial host. though 1t is very much
further away. Olgol, the demon star" which
undergoes a partial eclipse every three days
from its huge. dark companion, Is believed to
have a diameter exceeding 100000 miles, while
the Invisible associate Is nearly as large as our
sun. its diameter being not far from $4,000
miles The companion Of Sirius, while faint. Is
not altogether hidden from human sight. But
It Is so far away from Its primary that fifty
years are required for single circuit around
their common centre Of gravity
OF all the fixed stars. Alpha Centauri. in the
southern hemisphere, Is still believed TO be the
nearest to us. its light taking only four and one
quarter years to cross the abyss between u.s. II
II travels las it doubtless does) at the same
rate as the suns light. which reaches the earth
in eight minutes. The star G1 Cygni has long
been regarded the nearest one in the northern
hemisphere, and distant about seven and a
quarter light years; but Capteyn's parallax COM
putations place Latande Piss trife nearer.
1t takes the light of Sirius between eight and
nine years to reach us. the Pole Stars forty
four years. and Vegas nine,y-six years. while
the parallax which Elklns finds for Arcturus IN
dicates a distance OF $50 light years
great many Of the so-caled fixed stars slowly
shift their positions in the skies relatively to
the other stars And. when their distance from
US Is once estimated. some idea OF the velocities
with which they move be formed. For
years the palm has been accorded 10 Groom
bridge. 1880. which Is credited with speed OF
1913 miles second. But II Pritchards parallax
for Mu Cass,op@ia is right. that star is flying
through space at the rate Of 302 miles n second:
and Elkins's figures compel one 10 believe that
Arcturus has a velocity Of 376 miles. The elder
Herschei believed that. with a sufficiently pow
erful telescope all nebuln could be resolved into
star clusters. This has proved true of only a
few. however. Hundreds Of these clouds of dust
and gas are now known. which retain their filmy
character. The forms OF some Of them strength
en- ones belief in the soundness of the theory.
advanced by Kant and Laplace, that suns and
planets are evolved from such material Mr.
Gore devotes an interesting chapter to this class