Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-01-20
METALLIC "ERUPTIoNs" ON THE suu.


There some Optical ulusionp
From the New York Tribune.
The light which we receive from IN. nm,
u Is generally conceded by astronomers 4.
emitted by a mixture Of metallic yapors
heated TO incandescence and arranged I'm
oetached but closely associated clouds IN
layer known as the 'photosphere." Out
side OF II Is a thin scarlet stratum. mads
UP mostly OF hydrogen gas. with a wave
ike or fame-like irregularity of surface
Ihis Is called the 'chromosphere" Reach
ing stu further out into space and much
more attenuated. is the corona When The
suns apparent disk is wholly covered hy
'he moon one may see on the edge through
Telescope another class OF phenomena,
called prominences. which are also dis
cerniple with a spectroscope at other time
oy proper manipulation OF that instru-
ment- Some Of these prominences have 4
quiet appearance and rounded form, and
seem to be composed OF exactly the same
materials as the chromosphere, but otherx
containing metallic vapor in abundance
have the shape OF Jets develop with aston
ishing rapidity and are sometimes spoken OF
as 'eruptions" And the supposition that
these latter are produced by the election Of
matter from below the photosphere hos led
many students Of solar operations to think
L
bulent condition. A paper which A BrsD-
ter. 1r., contributes to the last number Of
Astronomy and Astro-Physics." however,
contains several reasons for supposing that
the last mentioned regions are in a COM
paratively tranquil state. and that there v
something deceptive about these so-calisd
| "eruptions."
1t is first pointed out that when the limb
| OF the sun is examined with a spectroscops
such metallic vapors as are perceptible at
all seem to be buried underneath the lighter
gases, even where prominences most often
occur. This arrangement of materials n
also discovered In the most enormous jets.
Apparently the heavier substances are not
thrown UP to such heights as the hydrogen
Stratificatfon In thus revealed. says Mr..
Brester, and sterilization means quiet. TO
guard against the supposition that the
metals may really be heaved upward. hut
become spectroscopically invisible through
cooling. the reader is reminded that there
| IL heat enough in the solar atmosphere.
| away out near the apparent limits OF the
| corona, to vaporize and reveal. by char
acteristic lines In the spectrum the Iron
and sodium Of a comet coming into thai
exceedingly rariied envelope from outer
space. Again. IL is admitted by Young.
certainly a high authority. that the hydro
gen prominences (Which are OF the ouics-
cent type seem to form above the chro-'
mosphere by local heating or lumin gus
agitation" OF the gas already there. and
not by a transportation Of material And
when they disappear, says Lockyer, the
matter does not disappear. but changes
its state" such modification being chiefly
one of temperature. Mr.. Brester thin'Ss
| that this holds good in the case OF metallic
prominences also. The curious changes Of
direction. the fantastic shapes and the
enormous area of some of these latter MIL
itate against the election theory. II -
hard to conceive. too. of gas being shot
upward through gas and from mines with
plastic walls at such a velocity as to carry
and have IL remain In slender Jets instead
of diffusing itself. These wonderful veio<i-
| ties moreover-2Oo miles a second for Loo
seconds, and perhaps 500 miles a second at
| the start-are SO marvellous as 20 make
actual transportation of matter appear i'm
probable. 1t is further noted that almost
absolute quiet appears In close proximity
to tremendous eruptions. and on the site
fof prominence Immediately after it's sub
sidence- And some Of the metallic prom
inences which develop transcendent speed
have no visible connection with the atmos-
phere. but seem to originate at considsra-
BILE elevation.
These and other arguments adduced by
Mr.. Brester have force; but IL must be re-
membered that lines in the spectrum have
been displaced. while prominences near the
center OF the solar disc were under EXAM
inaton; and from the displacement IL has
been computed that the luminous matter
most directly toward the observer Cor out
ward from the SUM at these same veloci-
| ties already referred to. Astronomical
spectroscopists pretty generally agree IN
| accepting that class of testimony. Mr..
Brester, though intmates that there may
be some error OF Interpretation which
would invalidate #