Dodgeville chronicle. [volume] (Dodgeville, Wis.) 1862-current, 1869-08-20

view of the corona, as seen at Des MONIES,
Iowa, by the writer, through telescope,
sketched by him Immediately after the
total observation had passed, and then sub
mitted to several of the scientific observers
present, all of whom recognized it as an
accurate portraiture The cut also shows
the ose-colored protuberances, the largest
of which were seen by him, but for the
smaller ones, and the exact description OF
all, he is partially indebted to others, who
made them the special subjects of Observa-
ton, while he directed his attention to the
corona, during the 171a seconds which in
tervened between the apparent contacts OF
the eastern and western edges of the lumi-
naries ...lff< -H@1
The circular figure on the accompany
ing diagram represents the moon, her dark
side being turned toward the observer.
Though her actual diameter is 1914 times
less than that of the sun, yet she is so
much nearer to us that, at the time of the
eclipse, her apparent diameter was to that
of the sun as 81 to 20, so that the sun was
totally Obscured during the 2 minutes 521a
seconds required for her to pass over a
space equal to one-twentieth part of the
suns diameter. The apparent motion of
her centre was along the line G to D, while
the apparent path Of the suns centre may
be represented by the line B to A, and the
direction of the north and south poles of
the heavens by the points marked N and
s. The letter z represents the direction of
the zenith the letters R and L, the direc-
ton of right and left. 1t is evident from
the diagram that r was nearly in the di-
rection of northwest; G, nearly northeast,
and L, nearly southeast.
That the light-colored rays and the dark
rose.coIored protuberances (the latter re-
presented by black spots on the diagram)
belonged to the sun, and not to the moon,
is evident from the fact that when the
edges of the sun and moon conceded at d,
at the first instant of total observation, the
moons edge tapping some distance over
the sun at G., the protuberances on the up
per left side were visible, and the corona
on that side was larger, while, when the
moon had advanced so that the edges near
ly connected at G, and the moon Tapped
over at d, the protuberances on the ID
side were visible, while those on the G side
came into view, and the corona on the lat
ter side was largest. Accepting this view
we obtain gauge of dimension which en-
ables us to approximately measure the di-
mansions of the several parts of the coro-
ma and the protuberances. -.
Thus: the sun is known to subtend an
actual diameter of 351, 1856 miles, while his
apparent angular diameter at the time of
eclipse was 81 minutes, 37.6 seconds of
space, corresponding to 442.76 miles to
each second, or very nearly 1900 miles
(70, 979. 76) to each digit, or twelfth part of
the suns diameter. But in order to find
the total amount of projection, it is evident
hat of fob int INF n u
the amount of protrusion beyond the edge
of the moon, but also the amount due to
the overlapping of the moons edge at the
point and instant of observation.
THE CORONA.
The corona was remarkably different
from all preconceived notions on the sub
ject, and from all previous descriptions,
both in size and shape. 1t has always
been represented as nearly annular (ring
formed), of about equal breadth all the way
round the edge of the moon, and not more
than one tenth of her apparent diameter
The corona of Saturday last was exceed
ingly irregular in its outline, and in some
places projected to distance fully half
that of the apparent diameter of the moon,
or nearly 100000 miles, Our diagram
shows the relative lengths of the several
portions, except that on the sides the
length is slightly CONSTRUCTED.
The greatest length was almost identical
with the direction of the moons path
across the face of the sun, which very
nearly conceded with the plane of the
elliptic. From the east side direction
from d. a mass of light shot out to the
distance of five or six digits it was about
thirty degrees wide at the base, and shaped
nearly like the remote half of silver
poplar leaf Near the moon it shone with
an almost uniform white light, but within
short space it broke up into brilliant
rays, almost parallel with each other and
all pointing nearly towards the centre of
the diagram. Still farther out these rays
assumed more of streaky character,
seeming to lie against a darker back
ground, and towards the summit they
faded away into more diffused and milder
light, though still distinct and bright.
Near the extremity it appeared more like
a cumulus cloud, but the central direction
of the rays was plainly visible. 1t melted
away into the azure background almost
imperceptibly, but the outline was perfect,
except at the very extremity of the leaf
shaped mass. On the other side of the
disc direction from A, c. was CORES