The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1870-04-22

skies, and again the scene OF interest lies in
that marvellous region of the heavens which
forms the extremity Of the keet of Argo. In
this glorious region of the skies stars are
spread with a profusion which surpasses any
thing seen from our northeriy stand point
From Sirius southwards towards Canopus the
density of stellar aggregation steadily in
creases. Thence along the keel of the great
ship stars of all magnitudes are spread in
greater and greater profusion, so that, as
humboldt tells us, the SKY here sheds ra-
dance resembling that of the young moon,
and by the mere increase of light one can tell
without turning towards Argo when her re-
splendent keel is rising above the horizon.
But it is where the Milky Way narrows down
towards the great nebula in Argo that the
climax of splendor is reached. 'It is not
easy, writes Sir John Herschel, 'for lan-
gunge to convey a full impression of the
beauty and sublimity of the spectacle which
this nebula offers, it enters the field of
view of the telescope, ushered in as it is
by so glorious and innumerable a procession
of stars"
When Sir John Herschel wrote thus, there
lay in the very heart of that amazing nebula
a fixed star which shone as brightly as Aide
baran or Antares. Eta Argus, for the star
has received no special title and is spoken of
only by it's Greek letter, had been described
by Haley as a star of the fourth magnitude.
Later the French astronomer Lacaille saw it
Of the second magnitude. When Sir John
Herschel was pursuing his wonderful series
of observations on the Southern heavens, this
star shone as a moderate first-magnitude star,
and in his noble picture of the great nebula
(Which lies before us as we write), the star
is placed in the very densest part of the ne
bulOus matter, and close by the borders of
the mysterious vacuity which marks the GEN.
tral region of the nebula.
Since 1887, however, the star has exhibited
new and even more surprising changes. 1t
increased in splendor in strangely fuctuat-
ing manner, occasionally losing brilliance for
awhile, to renew its glories presently, until at
length, in 1S43, it surpassed Canopus in
brightness and rivalled even the blazing
Sirius. Then began a long process of deca
dence, the star falling gradually away from
magnitude to magnitude until it almost passed
the limits of naked-eye vision, and came to be
described as o low siXth-magnitude star.
Meantime, the nebula around it waxed in
splendor. When Herschel had been at the
south cape the nebula could barely be seen
with the naked eye on the darkest and clearest
nights; but lately it had reached SO high
degree of brilliancy that it was visible even
when the moon was shining brightly enough
to obliterate all but the leading stars.
Then, as we lately recorded, news came
from the Melbourne Observatory where
Grubb's splendid reflector is at work in the
able hands Of La Sueur, that the nebula had
changed in form since Herschel had depicted
it. In particular it was remarked that all
round the star Eta there was either no
nebula or but little, whereas during Herschels
observations, as we have mentioned, the
nebula was brighter round this star than
elsewhere.
And thus it happened that whereas Sir John
Herschel had conceived the nebula to lie far
out in space beyond the stars with which it
seemed 10 be associated, LIE Sueur argued,
from the remarkable changes to which the
nebula has been subjected that it cannot be
SO enormously extended as Herschels views
would imply, and in all probability lies nearer
to us than the fixed stars in the same direc-
tion. Before this the present writer had
urged that the nebula is really, and not
merely in appearance, associated in the most
intimate manner with those fixed stars.
And now we have intelligence respecting
the star which throws new and unexpected
light on the whole subject.
1t will be remembered that in May, 1866,
star suddenly blazed out in the constellation
Corona (close by the uplifted right arm of
Bootes). Studied with the spectroscope by
the eminent physician Higgins, this new
object was found to be in a strange condi-
tion. Its rainbow tinted spectrum, crossed
by multitude of dark lines, showed that it
was, at least for the time, a sun like ous
OWE, an incandescent body shining through
absorbent vapor But besides the dark lines
there were seen several bright lines, and
these lines interpreted according to the usual
principles of spectroscopic analysis taught US
that the star was surrounded by glowing hy-
drogen. The new orb was, in fact, sun in
flames. Gradually those flames died out and
now that orb has seemingly returned to the
condition it was in before the outburst, and
can still be seen by the telescopist, shining
with the faint radiance Of a tenth-magnitude
star amid the depths of space.
And now it appears that the wonderful va
riable in Argo is also star in flames. Its
spectrum exhibits the same characteristics as
that of the star in Corona, except that the
dark lines which cross it are somewhat less
distinctly marked. There, however, are the
bright lines which indicate the existence Of
glowing gas around that distant orb, and the
position of those lines serves to show in the
clearest manner that the star like the orb in
Corona, is covered with hydrogen flames.
Lines, as yet not measured, seem to corres-
pond with we'll known bright line in the
spectrum of the solar prominences, and with
a line of nitrogen.
Bnt the spectroscope has also given very
striking evidence respecting the association
between the nebula and the star. All around
the star M. lie Sueur sought for the character
istic spectrum of the nebula. He could not
obtain that spectrum from any part OF the
space which Immediately surrounds the star,
fact which shows most conclusively that the
absence of nebulous light here is not apparent
Cor due, as might have been suspected, to the
fact that the stars light simply overpowers
- llo oI,,lo