The morning news. [volume] (Savannah, Ga.) 1887-1900, 1896-06-07

upon the largest telescopes does not ex-
coed 500, but this enormous maguifica-
IOn IS or but little real value. EXCEPT
upon very faint stars The maximum
power which can be used upon the sun
moon and planets. with advantage. does
NOT exceed l.otN or l.5f4. and even a power
OF 80 or So is often far more satisfactory.
WIKI a power OF loo or l,sN the moon
appears under the same conditions as IL
u were viewed with the naked eye AZ a
800 feet square could thus be recognized.
and cities, canals and any prom nauJ
evidence Of highly organized life could
The first look through a large telescope
Dy those not accustomed TO IL is often
menl taits 10 perform what IS claimed Tor
II, but the chance observer falls 10 prop
erly 10 appreciate what he sees.
A great enemy of large telescopes is the
unsreadiness Of our own atmosphere. The
dust, smoke and light of cities are very
objectionable in fine telescope work, and
that is why the worlds large Observable
ries are located away from the haunts
OF men upon high mountains, where the
ar IS clear ana still since the intro
duction OF electric lights some very eX-
cellent telescopes located in cites have
been rendered almost useless. For this
reason Prof. swift moved MS telescope
Southern California, where the atuos-
phere is unsurpassed for clearness and
Much Of the success in using a telescope
depends upon its perfect steadiness. for
the instrument magnines not only distant
objects, but also every tremor IN us sup
port in the same proportion. When tel
escOpe is eQuatOrially mounted upon
firm support the pleasure to be derived
from, ffs iIsas is of a very fascinating and
lofty character. With the naked eye
from 1900 to 5000 stars are visible, while
with the largest telescope the number Is
perhaps 100,0O0O00.
one of the greatest advances made in
astronomical science in recent times is
in the direction of celestial photography.
In few hours a section of the heavens
can be in this way mapped out with a
precision and fullness that would require
years by the old methods to attain. 1t
is a curious fact that stars too faint to
be seen in the largest telescopes impress
themselves upon the Photographic plate
clearly. The explanation lies in the fact
that while the sensation of sight is a
mOmentary effect produced upon the or
gans of vision, the impress upon the
Photographic plate is an accumulated eff
feet of several hours exposure. A few
years ago the great ObserVatories Of the
world agreed upon a gigantic plan of pho
tOgraphing the entire heavens, and then
work is now going on with great success.
The question of an increase in the size
and power of telescopes depends upon the
production of glass discs Of sufficient size
and quality. At present the limit Of skill
in producing these discs seems to be
nearly reached, but it is not at all i'm
probable that new discoveries will be
made in the manufacture of glass; and
improved methods will be employed IN
shaping and polishing the lenses, so that
muCn larger ana more powerful lnSkIu-
ments will doubtless be made in the flu
ture. While forty inches is the maximum
diameter yet actually attained IN object
glasses there are in process of cOnStruc-
ton in England and in Paris glasses of
much larger diameter. Some of these are
to be constructed in sections, but the final
results are very uncertain.
A telescope may be regarded as great
eye or light gathering device, whose
power Is as much greater than the natural
eye as the object glass is greater than
diameter Of the pupil Of the human eye
is one-fifth of an inch, while the dame
ter of the largest telescope objective in the
world Is forty inches, and as the areas
of circles are proportional to the squares
of their diameters the theoretical power
of this enormous tense is 10000 times IS
great as that of the naked eye.
Previous to the present century even
a six-inch telescope was very rare, but
made it possible to produce an Instrument
of more than forty that power. The
United States leads the world in large tel
inch objective the next Is the Lick, with
a thirty-six-inch, then the equatorials of
Washington and the University of Vir-
ginia each a twenty-siX-inch and num-
Der of others above twelve inches. The
largest glasses IN Europe are the thirty
inch of the Pulkowa observatory I'm Rus
STA; the thirty-inch at Nice, in France; the
twenty-nine-inch in Paris; the twenty
seventeen of Vienna, and the twenty
five-inch Of Mr.. NewalPs, at Gateshead,
EnEldnu. II - d CufAOuS LdNl llldL SOlllb
of the most modist telescopes Of the
world have contributed most to astronOm-
ical science. The largest glass at the
great Greenwich observatory IS only
twenty-four-inch. The observatory at
Bonn, in Germany possesses a glass no
larger than six and one-hah inches, and
yet with this celebrated instrument some
of the best astronomical work of the world
has been done. The positions of more
than 100000 stars have by 1t been deter
mined, with great accuracy. The skillful
and accurate work of Father Secchi at
Rome with a 9.6-inch objective is unsur-
passed for it's reliability and great scien-
tihc value. A necessary complement to
any telescope is a keen eye and a good
judgment, for after all the greatest reve-
lations in astronomical science are those
dedUced from visible phenomena, which
of themselves, particularly TO an untrain-
ed mind, mean but little. Otis Ashmore.