Iron County register. [volume] (Ironton, Iron County, Mo.) 1867-1965, 1882-05-25
Spots On the Sun.

sunday, April 16, will pass into the
history of astronomy SIS an eventful day.
From morning to night the solar surface
was Ia violent agitation, while colossal
centers of cyclonic activity were clearly
seenin telescope. There were Ill spots
seen during the day, the largest being
$1,000 miles in length and $4,000 miles
IN width. These were arranged in ten
clusters, none being far from the egua-
tor OF the sun. Thirtv-four spots was
the largest number seen in any cluster.
Each aggregation of. spots had one or
two very large, the remainder varying
In size from medium to small. The
Large spot was first seen at this observs-
tory at a. m. April 10, already ad-
vaneed on the eastern edge of the sun
10 degrees. Throughout the 18th it did
not display unusual turbulence, but dur
ing Saturday night activity set in, for
on Sunday morning its appearance and
internal structure had materially
changed. 1t was cut into four portions
by what was termed "bridges" of fire.
But these bridges did not maintain the
widening, contracting, or bending into
everchanging forms. They were white
hot; that is, whittier than the solar disc
presumably hotter. One could not see
them move any more than the hour
hand of clock can be seen in motion,
but on returning to the telescope after
an interval of half an hour displace
ment could be detected. AT a. m.
two tongues of fire were pointing to-
ward each other from opposite sides of
the abyss, and at 1890 p. m. passed,
leaving quite a space between. Shortly
after they began curvature, which, at 2
p. M, formed a circle, clearly ease of
solar cyclone.
A sun-spot is composed of two por-
lions, the umbra and the penunbra.
The umbra is the dark central portion,
while the penumbra or border is many
shades lighter, yet much darker than
the disc of the sun. The penumbral
fringe looks like down-rush of matter
into or upon the umbra, its sides are
inclined, and are striated throughout,
the STRIFE having the appearance of
willow leaves laid on the incline, parallel
to one another, their small ends project
ing over the black umbra, giving the
edge of the penumbra serrated form,
like saw teeth. When many of these
projections join and receive an impulse,
they pass entirely across the umbra,
forming an incandescent bridge. And
yesterday every large spot had bridges
complete or in process of formation. In
the large chasm, about 4 80 in the after
noon, one of the bridges split lengthwise,
the separation requiring more than two
hours, while the ends of several jets
were tufted and tassled with filaments of
white hot matter, which, ceincidlng
near the center of one of the largest di-
visions, presented the appearance of the
whirlpool rapids below Niagara should
that frenzy of water be instantly rem
dered mOtionless. We have no spectre
scope, but with one Ofgood dispersion
we should have been able without doubt
to behold movement in the troubled
mass; or, at all events the displacement
of hydrogen lines in the spectrum of the
seething vortex. Neither have we a
micrometer; hence were not able to
arrive at accurate measurement. But
the results above, 81 900 miles in length
and $4,000 miles in breadth, are within
1000 miles of the truth. The width
given is at the maximum point; the spot
contracting toward the solar equator,
gives it the shape of a rude triangle.
Calculating its area, we found that
thirty worlds like the earth, side by side,
could plunge at once into the mighty
gulf and be destroyed in moment.
Measurement was made by time of
transit of longest diameter of spot over
central wire in eye-piece, the time being
ten seconds. But one second of time of
the earth's rotation equals Is seconds of
arc, celestial space. One second of
space on the sun is $50 miles, and the
diameter of the spot being $50 seconds
arc, made 60 800 miles. Several spots
beside had diameters of from 5000 to
10000 miles, which, forming centers of
clusters, gave the solar disc an impress
sive aspect. There were three facule
also on the sun-brilliant spaces much
brighter than the general surface. The
terrestrial atmosphere being in fine con-
dition for telescope manipulation, the
rice-grains," granulations, and pores
all over the sun could be distinctly seen.
Altogether the day was one of moment
in the means offered for studying solar
phenomena.-Prof. Lar}5jn, in Chicago
Tribune.
The Cherokee Rose.