Omaha daily bee., 1895-12-29

VI the elgnty telescopes IN use To-Day WIN
object glasses of twelve inches diameter or
more, seventy-six are in stations north of the
equator, and only four, or one-twenteth of
the whole number, in stations in the south
ern hemisphere. OF this scanty proportion,
too, not one has an object glass exceeding
thirteen inches in diameter, or, in other
words, there is no refractng telescope south
of the equator today of one-half the size of
our largest instruments in North America or
European stations. When we consider the
comparative novelty and possibilities of the
southern field of observation it is really veX-
ing to see endowment after endowment going
into the erection Of new northern observator-
les or additional telescopes, when the south
ern hemisphere is so destitute.
"There is misplaced local pride, too, on
the part of well-meaning contributors which
insists blindly on the erection Of an OBJ
sarvatory, as IL 1t were local monument or
attraction. The atmosphere of any large city
is inevitably clouded and unsatisfactory for
an astronomical station, and the essential
freedom from jarring cannot possibly be se-
cured within city limits. Moreover, the in
PRODUCTION of electric lights, brilliant and de-
sirable as they are for city service, Is found
to interfere seriously with the observation of
faint objects, such as comets, nebulae and
zodiacal phenomena. In truth, the ldeal
place for the location of an observatory is
in the heart of great desert or
on an isolated mountain peak but these stu
atoms are doubtless less desirable than city
streets for advertising purposes, il obserya-
tories are to be erected chiefly as memorial
tablets or for the attraction of sightseers."
POSSIBILITIES OF ASTRONOMY.
"What are the probabilities or possibilities
of marked advances in our scientific knowl-
edge Of the stars and planets?'
Half century ago." said Prof. Pickering,
many people were inclined to look upon
astronomy in the light of dead science, and
il must be confessed that there did not seem
tn hs ambitious b.
servers in the discovery OF novelties with the
appliances then at hand. But great change
for the better came with the application OF
tho spectroscope and photography to astro-
nomical research. The spectroscope may be
regarded as second only to the telescope in
the importance Of its contributions to our
knowledge of the physical properties of
the stars. 1t has given us information
Of the origin and composition OF the heav-
emily bodies otherwise unattainable and also
of the velocity and peculiarities of their
movements.
"The increase in the size and power Of
telescope object glasses has been remark
able also during the half century just clos
ing. In 1850 the largest refracting tele-
scopes were those at the Russian National
and Harvard observatories, both of 15-inch
aperture. The object glass Of the refrac-
tor at the Lick observatory today is thirty
six inches in diameter, and the one lately
constructed for the Yerkes observatt : of
the Chicago university is forty inches in
diameter. At stations whsre clear atmos-
phere permits the full utilization of the
greater power of the enlarged telescopes
their service in the extension Of knowl-
edge OF the heavens is OF high value
I'm photography as applied to astronomy
the principal advance to be looked for is
in the increase Of sensityeness of plates,
but 1t is unfortunately true that certain
difficulties in the way of their use will
increase with the sensitiyenesa.
The Jogging OF the plates on moonlight
nights is already SO great that long ex-
posures cannot be made with telescopes
of large angular aperture, and any marked
increase OF sensltyeness will make II i'm
possible to work to advantage in the vi
cinity Of a large city on account OF the
illumination Of the atmosphere by artificial
light. 1t VIII then be necessary 20 take
the photographs in places far from centers
OF population and preferably at great ele-
vatlons, where the rejecting atmosphere is
diminished in amount.
"As to the possible enlargement by this or |
other means OF the number of stars known |
to us no approximate limit can be fixed. 1t |
has been estimated that as many as 20, 900 600 |
distinct stars will appear upon the plan |
isphers OF the visible heavens when COM
pleted by the Photographic reproduction OF |
all stars down TO the fourteenth magnitude. |
In the Investigation Of the planets the appli- |
cation OF photography is OF comparatively |
slight service, This Is particularly illustrated |