Evening star. [volume] (Washington, D.C.) 1854-1972, 1909-02-16
STUFF THE STARS ARE MADE OF
Use of Photography in the Study Of
Nebulae.
From the New York Tribune.

Such astronomers as wish to interpret
those luminous clouds out Of which La
place magined that worlds are made will
be grateful for a volume recently issued
by the Lick observatory. Before his
death the late James E. Keller, at one
time the director of that institution, made
the discovery that the number Of nebulae
in the heavens is vastly greater than any
are at least 10000, and that the major
ity of them have spiral form. To facil-
itate a study of these mysterious and
fascinating objects he began a campaign
Of photography, which was not quite COM
pleted when he died. The work was fin
ished by other members of the Lick OBJ
servatory staff. and now, after many nee
essary delays. a collection of rare value
has been given to the world.
Photography helps the astronomer in
several ways. 1t makes more accurate
record than can be made by hand Cen
orally speaking, 1t does so with astonish-
ing quickness, although with certain sub
jects an exposure Of the sensitive plate
for hours is necessary to secure satisfac-
tory detail. Copies of such pictures can
be made easily for distribution among
experts. Finally. photography reveals
much which cannot be detected usually
The keenest eye responds only to the i'm
pressions Of an instant. The action of
light on a chemically prepared plate Is
cumulative. Some of the photographs of
the great nebula in the constellation Of
Orion. for instance, excited profound as
tonishment because the extent Of the more
delicate parts of 1T was utterly unsus-
pected. 1t should cause no surprise,
therefore. to learn that in scarcely more
than a hundred celestial areas selected
for his research Prof. Keller found 744
nebulae not previously recorded His
pictures. which have been reDroduced with
remarkable fidelity, were obtained by the
expenditure of exceptional patience and
skill. He made use of a telescopes pres
ent to the observatory-which, in spite of
Its fine optical qualities, could be aimed
continuously with the utmost difficulty.
Through what succession Of stages of
development nebula is destined to go
Prof. Keller does not indicate in his re-
port. Possibly he had not reached con-
clusion on the subject. STILL there is
something suggestive in his choice of
subjects for publication. Some of these
are SO lacking in definite shape as to re-
mind one of the primitive chaos referred
70 In the Mosaic story of the creation
The great nebula in Andromeda, exqui-
sitely depicted in this volume. looks like
an enormous disk. seen nearly edgewise
At the center is a condensation much
brighter than the rest Of the cloud. while
the outer portion seems to be breakine
up into rings. beautifully in harmony
with the conception of Laplace. There
you see the possibilities of a sun, the ma
terial for the planets and evidences of a
motion such as the great French
man deemed essential to the final result
In several photographs nebulae are init
mately associated with star cluster
the Pleiades for instance-as If trans
formation was there in progress. Other
clusters. entirely devoid Of nebulous ap-
pendages. are represented possibly with |
the intention of limiting at finished worlds.