Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1878-08-21

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Phetotelespectrosco 1t the Eclipse
The Corons N Outlying Mass d Nat.
Ter Rejecting Sunlight
Effect Of the Corona's Heat ON Edi.
sons Tasimeter.
New York dispatch u Chicago Tribune.
Prof. Henry Draper, the. eminent
astronomer who observed the recent
eclipse at Rawlins, Wyoming Territory,
reached home to-day. Prof. Diapers
party included his wife, Prof. Barber,
Prof: Morton, and Mr.. Edison, and was
private enterprise. In an interview
with Times reporter, Prof. Draper
said: "The observations we proposed to
make on this occasion were intended to
ascertain definitely whether the light OF
the corona was due to special incan-
descent element, or whether ii was due
to reflected sunlight. or whether it was
mixture of both. In addition, l pro-
posed to take direct photograph OF
the corona itself, in order to see whether
the details of its structure could be
made out. was not looking for oxy-
gen in the suns corona, as was said,
for | have long known there was no
oxygen in the corona" After explain
ing his instruments, including a five
inch telescope and large photo-telespec-
troscope, the professor continued: " 1t
was the general impression previous to
the eclipse that it was entirely impossi-
sible to obtain a photograph Of the spec
trum of the corona, and In order to
give the best possible chance of getting
such photograph, resorted to ex-
ceedingly sensitive materials, known as
the lightning collodion process, furnish
ed me by Messrs. Anthony. This in
volved distilling large part Of the water
used, because, in the locality where we
were, the water contains either alkali
or sulphur, both of which are deleteri-
Gus. Immediately after the tOtality
was over and on developing photo
graph, | found the spectrum photo
graphs were continuous band, with
out the least trace of ring. l was not
surprised, because, during the totally,
had the opportunity of studying the
corona through a telescope arranged in
substantially the same way as the photo
telespectroscpe. These spectrum-pho
tographs, therefore, show that the corona
on this occasion did not consist of an
ignited gas giving a few bright lines,
but that its light was due either to re-
Election of sunlight by solid or liquid
bodies surrounding the sun like cloud
of meteors, or else that these meteoric
bodies were'raised to a white heat. The
observations made by Prof Barker, who
was next me in the observatory, were ar
ranged with view of determining this
very poin.. If the coronal light con-
tains the Frauenhofer lines, it is re-
Elected sunlight. If it is a continued
spectrum without those lines, it may be
due to solid or liquid substances raised
to white heat. Itturned out on max
ing the observations with an analyzing
spectroscope that the coronal light did
contain the Frauenhofer lines, and was
therefore reflected sunlight. think on
this occasion there can be no doubt we
have observed the true nature Of the
corona, and that its light is almost alto
gether sunlight reflected from bodies Of
q size to small to be seen as individuals
ut distance such rs that of the earth
from the sun, namely, 90,O0O,0 900 miles.
The light of the corona, according to
this view, on former occasions, has been
contaminated or mixed with light de-
rived from ignlted gaseous bodies
elected from the sun. The plain photo
graph Of the sun taken with my large
equatorial on this occasion shows that
the corona is not arranged centrally
with regard to the sun. The great mass
of the matter lies in the plane of the
elliptic, but not equally distributed, for
on this occasion it extended about a
degree and half from the sun toward
the west, while it was scarcely degree
in length toward the east. The mass Of
meteors, if such be the construction of
the corona, is therefore probably ar
ranged in an ecliptical form around the
sun. The photograph also shows the
curious plume-like forms of the coro-
nal matter toward the poles of the sun.
The observations taken by Prof. Morton
with the polariscope sustaining this
view Of the nature of the corona, viz:
that it is reflected sunlight, because he
observed radial polarization. He also
observed with hand spectIoscope the
Frauenhofer lines Of the coronal light.
Mr.. Edison directed his attention to as
certaining, by the aid Of his nevly-in-
vented tasimeter, whether the corona
gave forth indications of heat. The
tasimeter can be so arranged so rs to be
exceedingly sensitive to DETERMINATIONS.
ca thot tho hand Of n Distance of thraa