Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1892-04-15
Its Value in Astronomy and Import
ant Discoveries Resulting from
Its Employment.
Special Care Must be Taken in Secur-
ing Pictures of the Heavenly
Bodies.
BY this Method Stars are Revealed
that Are Invisible Through
the Telescope.


graphy, which ranks in Importance next
indispensable to the astronomer in his ob-
servations of the heavens, and it has re
Gently been developed TO such an extent
that 1t promises to rival, if it does not al
together supersede, the telescope as a
means of astronomical research. Already
1t has succeeded In supplementing human
vision almost beyond belief, and has re
vealed the existence of celestial objects so
faint and obscure that the most powerful
telescopes have failed to detect them.
Could the famous astronomers, Coperni-
Gus, Calico, kepier, and Newton, return
to our earth from the realms CT the I'M
known, and be permitted to revisit the
scenes of their former greatness it
is difficult 70 Imagine which would
most excite their interest and
astonishment-the wonderful revelations
of the telescope, the brilliant researches in
spectrum analysis, or the glorious achieve
ments OF celestial photography, the mar.
velous science that has recently developed
the most surprising results, and expanded
our views of the august scenes of creation
to an almost unlimited extent, having thus
laid foundation for our acquiring an an
proximate idea of the infnity Of space,
and for obtaining still further glimpses of
celestial scenery than even the largest
telescopes have revealed to our observa-
ton. As recent writer has well remark
ed: The many wonderful discoveries In
astronomy recently made by the aid of
photography have seemed to leave the
Older methods Of astronomical investiga-
ton far in the rear"
Many intelligent persons, who for the
first time were shown a stereoscopic pic
ture of the full moon, have doubtless mis-
taken 1t tor view Of a peeled orange, and
the truth is that an ordinary photograph
of the full moon does bear a striking re.
semblance to peeled orange.
The methCd by which these yiaws OF
the moon are obtained will doubtless be
interesting In connection with this sketch
Nearly every body knows that a stereospic
picture Of person or waterfall is Oh
tanned by combining two pictures of the
object taken from different standpo MT, sc
that each shows little around the side
and the two being combined make the
obj oct appear to st nd out ID lifelike per
spective. To produce the same effect with
the moon, advantage is taken of the fact
that she vibrates, Or rolls little upon her
center, IN revolving around the earth
(known as the moons libratiop), so that al
one time we see a little more of one side
than usual, and at another time more OF
the other side. When two photographs
Of the moon taken at
OPPOSITE LIBRATlONS
are combined by the stereoscope, the
lunar orb appears suspended before the
eyes like ball that the hand can grasp.
Every person Of mature age must have
frequently seen what is known as 1.-The
old moon in the new moon S arms" When
the moon, only few days after passing the
sun, appears as narrow crescent in the
western heavens, the Illuminated portion
of her disk is seen shining with a faint,
ashy light. This light comes from the
earth, and is reflected back by the moon,
just as the landscape is family visible in
full moonshine. A few years ago M
Jansen, of Paris, succeeded in producing
photographs of the moon that exhibited
this phenomen n very distinctly. We
find, then, that light which came from
the sun was reflected from the fields and
waters of the earth to the moon, was
thrown back from her rocky surface to the
earth again, and after this triple journey
through space still retained enough power
to stamp the faint picture Of lunar land
scapes upon Photographic plate The
photographs of the moon are obtained by
the aid of telescopes, the prepared plate
being fixed at the focus OF the instrument
in the place of the eye-piece. They are
produced only one or two inches in
diameter of two or three feet.
Many photographers use rejecting teIe-
scopes In which a concava mirror takes
the place of an object glass.
The moon is not the only celestial object
whose picture can be taken. Photographs
are also made of the sun. exhibiting the
dark spots ana the Interesting phenomena
observed during a total eclipse. The
planets Venus and Mercury have been
photographed while in transit across the
suns disk. Even the stars can be photo
graphed, and few years ago Professor
Draper succeeded In photographing the
great nebrla Of Orion, which 10 Ost astrcH
Omer5 believe to be an enormous mass oS
gaseous matter, containing in itself the
germs of future worlds and suns. More
nebul8 are at present known to astrono-
mers than there are stars visible to the
naked eye in the entire armament. ana
they appear like faint spots of light. These
objects are situated at immeasurable dis
tances from our earth, and all except the
great nebul8 in Andromeda, are visible
to the naked eye. On clear night, dur
the absence of the moon, this remarkable
nebula appears to persons having keen
vision as faint, cloudy spot, of an oval
form, and has frequently been mistaken
FOR comet. From time immemorial this
wonderful object has been an enigma to
astronomers, and It's true nature was never
understood until quite recently, whea Pro
lessor Isaac Roberts obtained an excellent
photograph of the nebula after exposing
his plate for four hours and it was then
found to be composed of numerous rings
of gaseous matter, apparently IN an
intensely heated condition and
doubtless passing through some
MARVELLOUS PROCESS OF EVOLUTION.
Many other wonderful and import mt
applications of photography to the heav-
ems have been made during the past few
year. and by its aid a new nebuIa was dis
covered IN the Pleiades By the two Henry
brothers, of the Paris observatory, in No
yember, 1885. The most wonderful cir
cum tan IN connection With this discov-
cry Is, that though the nebula is plainly
impres ed on the Photographic picture Of
this famous star cluster, it has bean, thus
far, too faint to be visible to the human
eye, even in the most powerful telescopes.
In the PIeiades, which form enc of the
mes interesting clusters of stars known in
the frmamrnt, the casual observer may
easily perceive Fix stars belon ging to the
group, and persons with acute powers of
vision may see twelve s. ars; but a large
eiescope will reveal at least 200 stars that
are invisible to the naked eye.