New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1904-01-24

a moon HSG SINS Summary o. Existing KnowleSgs
Atlas By William II. Pickering. OF Harvard
Doubleday, Page & Co.
THE PLANETARY SYSTEM: A Study OF Its
Structure and Growth By Frank Bursley Tay
lor l2mo, PIP 27S Fort Wayne: Published by
THE SOLAR SYSTEM. By Percival Lowell 12mo
PIP lS4 Houghton. Mifilin & Co.
Miss Clerke is not a practical astronomer her
self, but she has grasp of the work done
BY others. its significance and its limitations
.she puts these before her readers NTH mar
'yellous intelligence, truthfulness and fascina-
Itiol. The initiated will consult her latest vol
.ume with profit and eagerness, and the I'M
Initiated with amazement and delight Though
astronomy is probably the Oldest Of the sciences.
it has not yet got its growth" With the new
Instruments of research put at its disposal in
the last half century, the spectroscope and
Photographic dry plate it has made great adj
vances, but at the same time it has been con-
fronted with an entirely fresh set OF questions
What Miss Clerke has now undertaken to do Is
TO show where the frontier of knowledge lies
today, and In what directions further explora-
ton is apparently most needed.
Much Of the older astronomy dealt with the
effects % gravitation, motions in orbits, ce-
Iosli2I mechanics and external appearances
The newest inquiries relate to internal forces
causes the occasional disturbances OF an area
there which is from eighty thousand to one
hundred thousand miles in length? OF the yisi-
bic stars. something like two hundred million
In number. and ali believed to be suns Cnany
Of them bigger than Ours). how great proper
ton are hotter and how large a share are
colder? Can anything like system be detected
In this collocation, and are there any sugges-
tons about past history and future experienced
- 4Txr
unravelled or not unravelled at all. are at the
bottom Of astrophysics. Such problems. too, are
infinitely more interesting than the mathe-
maticaI ones with which Newton. Kepler and
Laplace wrestled-
a great many estimates have been made OF
solar temperature but anything like precision
Is rendered difficult by two phenomena
Some Of the heat radiated by the sun is abb
sorbed by the outer envelopes of that body, and
hence does not traverse space. Much is alb
sorbed by the earths atmosphere and does not
reach the ground After making allowance for
these influences, temperature of between 10000
and 1900 Fair. is regarded a modest guess
In time greater certainty may be hoped for. and
also indications Of possible huctuation in the
heat emissions. It is thought that the spots are
shallow concavities in the suns luminous cloud
shell, the philosophers. but observers not
agreed even upon so simple a matter this
Few experts think that the spots are the direct
result of explosive action Belief now incliDes
to the theory that they are the scene OF falling
material, elected elsewhere and cooled during
descent More positive information is needed. II
is especially important to know what lifts the
faculae, or patches Of especial brightness above
the general solar level and what is the relation
ship between them and the spots with which
they are associated. No explanation has been
found for the fact that spots are larger AMI
terval from maximum stage to another be- !
ing approximately eleven years Lockyer long |
ago noted that the lines Of the spectrum given |
out by the darkest part of a sunspot near the !
minimum stage differ from those at the maxi !
mum, whereas the spectrum Of the undlsturbed
portions Of the solar surface remains unchanged |
year after year Why should there be such a |
discrepancy? 1t has long been known that the
microscopic daily swing of the magnetic needle |
on the earth is longer at sunspot maximum |
than at a minimum, and that hysterical dis |
turbances Of the compass often accompany the |
appearance of unusually large spots. What Is /
the means by which the thus influences a
body ninety-thre million miles away? Not one |
OF the various theories advanced to account for /
It Is satisfactory enough to win general Gre
oence. Miss Clerke tells that there is no
evidence that Hertz waves reach the earth from
the