The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1891-06-28
STUDY OF THE SKIES.
Camille Flammarion on Photo
graphing the Heavens.
FORTY MILLIONS OF STARS.
The Giant Eye Of the Camera Annfhila tes
space and Remembers All 1t Sees
The Telescope Outdone.


group OF astronomers for the purpose of
applying photography to the study of the
stars, met recently for the third time at
the Paris observatory and agreed upon the
latest arrangements for photographing the
heavens
The idea of applying photography to the
curious things in the sky came to light on
the very day when the great discovery of
Niepce and Daguerre was publicly an
nounced In the memorable account which
Arago gave of it at the session of the
Academy of Science, April 10, 1889. The
INDUSTRIOUS astronomer perceiving at once
the many and diverse uses to which the
discovery could be put in astronomical re-
search, pointed out among other things
the possibility of obtaining good map of
the moon, and perfect representation of
the solar spectrum. But the methods of
photography at that day were too crude
to admit of securing satisfactory results.
However, about the year 1s45 Sizean and
Flaeault contriyed to take an excellent
photograph of the sun in 1.6 seconds, a
very fine engraving of which may be
found in Arago's complete works. In
lS49 William c. Bond, an American
astronomer. obtained good daguerrean
proof of the moon. The eclipse of the
sun on July %. 1851, was photographed by
Berkawski. at Koenigsberg, upon daguer-
reian plate, which disclosed for the first
time traces of the corona that enyelops
the star of day, and the eruptions that
emanate from its surface.
In 1857 Bond obtained a very clear
photograph OF the double star, Mizar and
Zita, IN the Great Bear, as exact in truth
as the micrometric measures, for / have
been able TO insert it as document in my
catalogue of double stars. 1t was at the
Harvard college observatory that these
first photographs of stars were made, and
it is there today that Professor Pickering
obtains such marvellous results that in
themselves they appear at least to equal
all those OF the twenty to thirty astrono-
mers composing the European congress.
NJ. Warren de la Rue, in England, and
N. Rutherford, in the United States of
America, ootained magnificent photo
graphs of the moon between 1857 and 1867.
that have not been surpassed. Let Us note
among these photographs some startling
stereoscopic views that show the lunar
globe so much in relief that it has almost
the form of an egg. This effect, some
what exaggerated, is due to the advantage
taken of certain movement of libration
III order to penetrate, more or less salts
factorily. the invisible hemisphere of the
moon. Warren de la Rue, to whom we
are indebted for these stereoscopic photo
graphs of our satellite, succeeded equally
in obtaining views of the planet Jupiter
with an exposure of twenty-six minutes.
Nj. Flaye, in France, has been one of the
n of 81 inai
photography. Insensiby. despite the po-
sition of astronomers who were first of
all mathematicians, photography made a
place for itself among the processes of the
study. 1t was applied with the greatest
success in observing the transit of Venus
in 1874, and again in 1882 In 1877 NJ.
Yanssen, at the observatory of Meudan.
obtained admirable photographs of
the solar surface, upon which the
observer seems to assist. so TO speak,
in the phenomena of the formation of
light. These photographs of the sun are
almost instantaneous, for they are taken
in hall one-thousandths of second. In
1884 Messrs. Paul and Prosper Henry,
while making maps of the stars for the
atlas of the Paris observatory, set them
selves to substituting photography for
direct observation, which, at the time, was
much more expeditions and certain. At
the same time. and afterwards. Messrs.
Pickering, in the United States; Gould in
the Argentine Republic; Gill, at the Ca pc
of Good Hope; Common and Roberts, in
England devoted themselves, with the best
success, to the practice of celestial photog-
raphy.
Thus gradually, insensibly, photography
came to take large part in astronomical
research. This part from day TO day be-
comes more and more important and also
more and more fruitful.
1t IS now proposed actually TO photo
graph the entire heavens, and il was with
this end in view that astronomers organ
lied the international congress which met
first in 1887. then in 1889 and again last
April. In its recent session the congress
paid attention very largely TO technical
details. \ score of questions were dis
cussed, involving all important points in
the preparation of plates, the process of
taking and developing, of reproducing
pictures from the stereotypes, etc. and the
methods of undertaking the great photo
graphic work, the division aof the zones
and the distribution of definite sections of
the heavens to various observatories and
observers for their respective fields of
labor.
Mague, director OF the Paris observa-
tory, made q statement relative TO the
progress made with the instrument which
he invented for photographIng the heav-
ems. and he suggested the time at which
he could begin experiments. Owing to
political events III Chile and troubles in
which some other states are involved. it
will not be possible for all 10 begin work
AZ exactly the same time.
Among other things the congress was
concerned with the choice of guide-starS,
that is 10 say. those which must constantly
be held at the same point of view in or
der that every star may be represented
upon the map by a point and not by a
measurable space. But what limit
should be placed upon the distance of the
After much cropping about the congress de-
cided TO leave to each observer certain
latitude not 10 exceed forty minutes.
Questions Of this nature, though secondary,
were novel and delicate, and the diver
gences of opinion brought out by them
were inevitable. Many difficulties were
suggested that can be solved only by long
experience; difficulties that will vary
with the physical and atmospheric condi-
tions of the various ohservatories. 4 her
tam liberty of action was therefore left TO
each observer the congress simply deter
mining the end 10 be attained.
The congress adjourned after having
made the best arrangements that the pres
ent state Of astronomic photography al
lows. for work of gigantic proportions
and immense difficulty. We may look
forward with no little confidence TO the
success of this undertaking which, accord
ing 70 the latest information, viii begin in
various parts Of the world simultaneously
during the summer.
The matter in hand involves the photo
graphing Of the entire heavens and the