Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1888-03-28

I y N'%Ao Adhtlf III 1917 lDO
traunhofer, independently and working
with better instruments, discovered and
named the lines OF the solar spectrum as
we know them now, and made map,
which L shall soon show you.
ORIGIN OF THE L1SRs.
"But the cause and meaning OF the
lines was not so easily discovered
Without stopping to dwell on a number
OF more or less partial anticipstions. the
/ work OF Bunsen Kirchof (who died a
few weeks ago), in 1859 first fixed public
attention aud gave full explanation of
the phenomena. What KIrchoff dis
covered was this:
81. That solid or liquid when in-
tensely heated gives spectrum which is
continuous from end to end, without
markings OF any kind, and the same is
true OF gas or yapor in a state OF great
density.
"2. That n gas or vapor, il not too
dense, gives, when intensely heated, a
spectrum Of bright lines or bands.
"3. That whenever the light from an
incandescent, solid or liquid. is made to
pass through cooler gas or vapor, then
Z, We get what may be called the reversed
/ spectrum OF the gas.
RAYS OF LIGHT.
"In other words, the gas strikes out
from the white light emitted by the
solid precisely through rays which it
would give itself if alone, and thus tho
gas or vapor, though invisible to the
telescope, becomes visible and identi-
fable with the spectroscope.
PICTURES.
Here the room was darkened and the
lecturer threw upon the screen n number
of pictures illustrating the constitution
OF the spectroscope and the methods by
which tho solar spectrum is compared
with known chemical clements. Among
them was one OF the original negatives
with which Mr.. Lockyer compares the
spectrum OF iron with that of the sun.
A list OF the elements SO far identified
was then given and the lecturer pointed
out that they all belonged TO the class
of metals. He called attention 10 the
fact that while the absence of nou.metals
from the solar spectrum is remarkable
and significant it still will not do to infer
with certainty that these elements do not
exist in the sun.
THE SUNS UPPER ATMOSPHERE.
ave pass next, continued Professor
Young, "to the consideration of the
phenomena OF the suns upper atmos-
phere-the suns meteorology, as it is
called" After few words as 10 the
cause and nature OF solar eclipses, the
lecturer went on to say that when the
sun is completely covered by the moon
certain scarlet projections are to be seen
hanging TO the edge of The black disc of
the moon. They seem TO have been
first noticed in 1873 by the Swedish
observer Vassinius, who thought they
were clouds in the moons atmos-
phere illuminated by the sunlight. II
was not then known that the moon had
no atmosphere. The fact that these OBJ
jects belong to the sun was first settled
beyond a doubt by photographs made in
1860 and in 1868. The observations
made by the spectroscope in India
showed that they were in the main great
clouds OF flames Of hydrogen gas. The
same year. little later, Jansen and
Lockyer independently. snd almost at
tho same time, discovered that it was
possible to see and study the prOmi-
nences at any time and in full daylight
with q spectroscope.
TIE PRINCIPLE OF THE THING.
Professor Young then gave an e1pla-
nation of the principle upon which this
method Of observation depends, aud
threw upon the screen series OF pic
tlres illustrating the different forms and
movements OF these beautiful objects.
He classified them rs cloud form or hv-
drogen prominences and irruptiye or
metallic prominences, the former being
large, diG'use, not usually very brilliant,
and consisting almost wholly OF hydro
gen gas, while the others, which abound
mainly in the neighbOrhood OF sun spots,
are generally smaller, more brilliant,
and active, and show in their
spectra not only the lines Of hydrogen
gas, but also those of many OF the metals,
especially iron, sodium. and magnesia.
He also showed some illustrations Of the
distortion of the lines in the spectrum
produced by violent motions Of the gases
at the solar surface and the effect pro-
duced upon terrestrial magnetism by
solar storms.
THE CORONA.
The last division OF the lecture was
devoted mainly to discussion OF the
corona visible in total eclipses OF tho
sun, and consisting mainly in the exhi-
bition of series OF pictures OF the
ecipses which have occurred since 1880.
He pronounced it nearly O solar phe
nomena. as is proved by the existence Of
a bright line in its spectrum which was
discovered in the eclipse Of 1869, and |
also by the fact that photographs of the |
same eclipse made at several hundred !
miles apart agree in all their principal |
features as exemplitied by the pictures
Of the eclipses Of 1871 taken in India |
and Java.
The lecture closed with brief account /
OF therecent UNFORTUNATELY ly unsuccessiuD /
Princeton eclipse expedition to Russia /
last summer, which the audience enjoyed |
very much.
The next and closing lecture, on Thurs
day evening, will be on the subject OF
Celestial Photography.
Captain Aiasiie's Portrait.
Richmond Commandery, knights Tenn |