The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1869-08-07


on the moons limb and enlightened by setting
sun. The preceding observation shows at once;
''First The gaseous nature of the protube-
RANGES (the lines being brght).
Second. The general similarity of their
chemical composition (the spectra correspond
ing line for llnc).
Third. Their chemical species (the red and
blue lines of their spectrum being no other than
the lines and of the solar one, and belong
inr as is well known, to hydrogen gas).
at is very certain that if an atmosphere
formed of the vapOrs of all the substances which
have been found i'm the sun really existed above
the photosphere il would have given a spectrum
at least as brilliant as that of the protuberances,
which we're formed of gas much less dense and
less luminous. it must, then, be admitted that,
if this atmosphere exists its light is so small
that it has escaped notice. / must also add that
this result did not much surprise me; for my in
Yestigations on the solar spectrum had led me
to doubt the reality OF any considerable atnO-
sphere around the sum- and am more and more
inclined to think that the phenomena of elective
absorption, ascribed by the great physicist of
Heidelberg to an atmosphere exterior to the sun,
are due to the vapOrs OF the photosphcrc itself
i'm which the solid and LIQUID particles forming
the luminous clouds are floating. This view is
not merely in harmony with the beautiful
theory on the constitution of the phOtO5pherC
which we owe to NJ. Faye, but even seems to be
necessary deduction from it.
On the day of the eclipse NJ. Jansen disco
yered method by which these red protube-
was unobscured, and, applying this new method
on the following morning, he soon saw the
bright lines formed by the protuberances; but
their length and arrangement showed that great
changes had occurred. 1t was evident not only
that hydrogen was the most important element
in these circum-solar masses, but that they were
rapidly changing both in form and position.
lie also observed that the bright lines
of the protuberances sometimes penetrated
into the corresponding dark lines of
the solar spectrum showing that the
protUberance extends over part of the suns
disc. 1t was to be expected that these protube-
RANGES, belonging to the sun, would exist not
merely on the margin, as seen from the earth,
but over its whole circumference, or over the
whole surfaces but during eclipscs the interposi-
tion of the moon makes its proof impossible.
Another advantage of the new method of OBJ
serving the spectra of the protuberanccs con
sists in the fact that these spectra are directly
compared with the spectrum of the sun ITSELF
whereas in cclipses, the suns spectrum being cut
off, it has been necessary to resort to graduated
scales to fix the position of the lines The principal
conclusions to which VI. Jansen arrives at the
time of his report, in November, are these
First That the luminous protuberances OBJ
served during total ecpseS belong UnqucstiOn-
ably to the circum-sOlar regions.
Second That these bodies are mainly or en-
tirely composed of incandcscent hydrogen gas.
Third. That they are subject to movements
of which no terrestrial phenomenon can give Us
any idea; since, though they are masses of mat
ter having several hundred times the volume of
the earth they change completely their form
and position in the course of few minutes
This latter statement is strengthened by the
independent testimony of the photographs taken
at Alden and at Guntoor, for, Mr.. De La Rue
states IA comparison of the two makes it evi-
dent that some change in the direction of the
Great Horn had occurred in the lapse of forty
minutes"
Important MS are the conclusions already ar
rived at, much remains to be learned. In the
last number of the Monthly Notices of the Royal
Astronomical Society Qondon) is an extract
from letter from j. BaXendall, in which he
says:-
"Recent observations and discoveries indicate
very clearly that this corona is not an appendage
of the sun. What, then, is it? or how is its ap-
pearance to be accounted for; In cOnversa-
ton had some weeks ago with Professor Roscoe
on the subject, | reminded him that in a paper
which | read to the Literary and Philosophical
Society in March, 1864, giving the results of n
discussion of an immense number of magnctcal
and temperature observations made in different
parts Of the world, / showed that these results
could be best explained by assuming the exist
ence of an irregular nebulOus ring circulating
about the sun, nearly in the plane OF the ecliptc,
and at a mean distance of O'lG9; and / suggested
to him that the reflection of the suns light from
| the matter of this ring might be the real cause
/ of the appearance of the corona in total solai
| eclipses'
Mr.. BaXcndall proceeds to show the improba
| bility that the corona can be the result Of re
Election from the earth's atmosphere, or from
any possible atmosphere upon the moons sur
face, New observations must determine tin
| point.
In conclusion, it may be briefly said that tn
present scientific theory of the solar constitution
represents or classifes it in three atmospheres:-
l. The solar photosphere, or visible surface
the white-light-giying atmosphere. 2. Th
cool, absorbing relatively non-luminous atmC
sphere. 3. The chromosphere, or local aggrC
cations at the prominences of an entirely er
veloping medium.