The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1869-09-07

carried out on albumenized plates, would be |
OF value to secure details in the rounded and |
massive prominences which appear at some
points.
1t is q curious coincidence that in this case,
as well as in the pictures made by De la Rue
in 1860, and the German and English party
last year, all the more interesting promi- !
nences are situated on the border of the sun
furthest from the advancing moon, and are
thus best shown in the pictures first exposed.
The most conspicuous prominence is that
which, at hasty glance, seems to resemble
the letter X, but, on more careful inspection
is perceived to be like an ear of corn. 1t
consists of a solid central mass inclined at
angle of about 45 deg. to the normal at
the solar surface, and with three branches
from near its upper end, one sweeping back
wards Ill direction generally parallel to the
solar surface, another forward, as concerns
the direction of the general mass, and third
branching out little below and running in
the same direction as this last The appear
ance of the main body, which is of q spindle
shape, and with spiral markings, is highly
suggestive of vertical motion which has
swept these whiffs of light matter into their
peculiar positions.
1t was believed by several observers that
this object moved rapidly while they were
watching it, but as the same positions are
shown in the eight different negatives taken
at Burlington and Ottumwa which contain it,
there can be no doubt of its permanent char
acter 1t appears, however, beyond
doubt, that notion amid the light
surrounding the sun, was OBJ
served, as there is much accord
ant testimony on the subject. But this mo-
ton, as we shall presently see, there is every
reason to believe, existed in the corona, and
not in the prominences, which, however,
might easily have the appearance of move
ment, if seen against a background of shift
ing light To this subject we shall refer
again when speaking of the corona
Immediately to the right Of this ear of corn
is seen region of soft light, among which
rise two similar spindle-shaped masses, in
clining towards the corn ear
To the left appears a mass of rolling cloud,
disposed in beautiful streams and curls, like
the smoke from bonfire or burning meadow,
swept gently towards one side by light
wind. In connection with these are some
small masses, entirely detached and floating
above the general body, as was the case in De
la Rues pictures
Other solid nodular masses appear at other
points, but the next most notable promi-
nence is one which attracted the attention of
all observers, and appeared to occupy posi-
ton on the lowermost edge of the sun. 1t
is most clearly shown in the last pictures
taken at each station and resembles in shape
great whale with body made up of dense
| cumulus cloud-matter, with long
tail clinging close to the solar edge,
and stretching some 10000 miles along.
| The length of the entire mass is
about 10000 miles, and the height of its
more bulky portion about $4,000 miles, while
! its length being about 70 600 miles, we would
have for It's cubic capacity, assuming that its
extent in the remaining direction is equal to
its height, about 54,SS0,000, 100000 cubic
miles.
To the right of this, and only showing its
entire length in the last picture of each series,
| is caterpillar-like mass of cloud matter very
much like the solid rolls of horizontal vapor
| which are sometimes seen passing over a
sheet of water. At one end rises a projecting
head, but the rest clings closely to the solar
| edge, and is indented with like divisions,
| giving it much the aspect of huge worm.
| The COr0nd.-The Ottumwa pictures, of
long exposure, are the only ones which give
us any idea of the true structure of the
corona; but they do more than / had hoped
in this respect. One of them, the last and
longest exposed, gives almost as full devel-
opment to this object as 1 remember to have
noticed with the naked eye The curved
structure of the rays is most Marked and the
varying intensity with which they are emitted
in different points.
The most distinct outbursts of the corona
light are evidently associated with those pro-
minences which are of pointed and flame
like shape; those of a massive description,
on the contrary, seeming to cast shadow on
the corona. This, we think, is to be noticed
in De la Rue's pictures.
These facts have peculiar significance when
taken in connection with others developed by
observations made during this same eclipse
In the first place, Professor e. G. Pickering
of the Massachusetts Institute of Technology
who was with our party at Mt Pleasant fol
the purpose of makingssvarious physical OBJ
servations, found that while the sky was
strongly polarized all around close up to the
corona, that object itself was not source Of
polarized light.
The instrument employed was tube hav
ing at one end large plate of quartz and a
the other a double image prism of Iceland
spar, made in the manner known as the prism
of Rochon.
On looking through this at the corona, tn
entire circle was in field with part of tn
surrounding sky, and two entirely distinc
, images of the entire area were seen tn
corona in both being colorless but projected
on ground of tints, complementary in tn
two images.
This would certainly indicate that the ligh
, of the corona was not reflected sunlight Wit
a spectroscope arranged to analyze the entir
light from the totality phase, Professo
: Pickering also found no dark lines in tn
} spectrum. This also points in the same di
I rection.
{ 1t would thus seem almost certain that tn
E corona is simply an electric discharge, nj
, doubt varying with great rapidity, as we SCI
/. in the case of the aurora; and to it's varia
q tions we may attribute those apparent mo