Evening star. [volume] (Washington, D.C.) 1854-1972, 1890-01-27
THE SUNS CYCLONES.
The Great Disturbances of the Solar At.
mosphere That Cause the Sun Spots.

Prof. Searle's lecture at the Catholic univer-
sity on the physical constitution of the sun
gave some interesting Information respecting
the sun spots. Calico, he said, first saw the
sun spots with the telescope. Sometimes they
can be seen with the naked eve the sun is
setting, but only rarely. IL we take an ordinary
opera glass. taking care to protect our eyes
with piece of smoked glass. it is probable that
we can see one or two at almost any time.
The spots are composed of u dark portion
called the umbra and a surrounding lighter
portion called the penumbra. They are irregu-
lar in shape, and not round, as they would ap-
pear through the opera glass. IL We look
through the telescope two successive days
we will see that the spots have changed their
size and position. They are some times smaller
and sometimes larger. and 1t often happens
that new ones have appeared that we did not
see before. But il will be found that all have
moved considerably to the right, and this will
be very noticeable every day.
THE suns REVOLUTION.
1t takes a spot on an average about twelve
and one-h half days to cross over from one side
to the other. They seem to move slowly near
the edges and more rapidly as they reach the
sun In the center they appear broader and
more round than at the edges, where they are
foreshortened and become elliptical From
these and other facts we conclude that the sun
Is, like the earth, globe revolving around a
central axis, but IL takes the sun twenty-five
DAYS to make q revolution. Sometimes the SPOT
that we have already observed will reappear at
the end of twenty-five days from its first ap-
pearance, but ordinarily they do not live as
long as that. The spots are found to occur
only in a belt each side Of the equator. They
are IN a continual state of flux and change, not
only in themselves, but in relation to each
other. They seem like the clouds in our air.
The penumbra consists Of rays or cylinders
radiating from the umbra. Not only do the
spots become elliptical as they approach the
edge, but the umbra Is noticed to approach the
inner side of the spot and sometimes to disap-
pear. Often there Is a spiral arrangement Of
the rays as they approach indicating a whirl-
pool motion. The whole character of the
nmbra indicates that they are holes into which
the surrounding matter is being drawn with
wild velocity. 1t is supposed that the bright
surface of The sun which We see is luminous
cloudy envelope or gaseous atmosphere, and
that the spots are centers of tremendous solar
cyclones compared with which
THE wILEsT ToRSADoEs
that visit are earth are no more than the slight
est breathings of a child. A velocity has been
observed in their movement DIS great as $50
miles second. When we consider the very
enormous masses OF matter, sometimes ten or
even a hundred times great as the whole
mass of the earth. which are projected upward
in that vay or thrown to one side or the other
or thrust down into the great cavities this
awful manifestation of power gives us a better
idea of what such a velocity means and of the
tremendous forces which work in Its production
There is still some dispute about the period
iclty of the spots. The extraordinary weather
this winter has been supposed to be due to the
absence of sun spots. but it is doubtful if any
real connection could be demonstrated. Every
eleven years there is a time when we have a
maximum Of sun spots, and half way between
there Is minimum of spots. This recurrence
of periods of activity has been remarked ever
since the spots have been under observation
Undoubtedly the spots have some connection
with the magnetic phenomena of the earth and
especially with the aurora, and through these
they may have some connection with the
weather. The texture next Friday will treat of
the sources Of the light and heat of the sun.