SUN-SPOTS.
_Grave Doubts._
HERBERT SPENCER says: "At present none of the interpretations of the
sun-spots can be regarded as established."
How numerous and how strange have been the theories promulgated as to
the character of the manifestations called sun-spots. The dark spots in
the sun have been supposed to be "solid bodies revolving very near its
surface," "Smoke of volcanoes;" "Scum floating upon an ocean of fluid
matter;" "Clouds;" "Opaque masses floating in the fluid matter of the
sun, dipping down occasionally," "Fiery liquid surrounding the sun
which, by its ebbing and flowing, the highest parts of it were
occasionally uncovered, and appeared under the shape of dark spots, and
by the return of the fiery liquid, they were again covered, and in a
manner successively assumed different phases;" "Interruptions of
continuity in the bright envelopes immediately surrounding the sun,"
"Cavities" etc.
_Overestimate of the Degree of Spot-shadow._
Public sentiment in regard to the degree of darkness which is disclosed
in sun-spots is exceedingly erroneous. It is believed that the spots are
really dark. ZÖLLNER, however, states that "The black umbra of a spot
emits four thousand times as much light as that derived from an equal
area of the moon." "The blackest part of the spot is intrinsically
bright."
_What They are not, and what They are._
These phenomena may not arise from disruptions taking place on the sun's
surface, neither from violent agitations near that surface. The
essential and intimate character of the so-called sun-spots may be found
in the interruptions of continuity in the fluid occupying the solar
cone-space. This fluid which we call sunlight intercommunicates between
the entire opposing surface of sun and earth, unless interrupted by some
temporary cause. Any cause which is capable of producing results of
such character and magnitude can only act by more or less completely
interrupting the development or transmission of this fluid.
The result of such action would be disclosed to us by a decreased
brilliancy in the direction of the sun. The so-called sun-spot would be
in character, magnitude, form, and shade proportionate to the extent and
character of the disturbing force. The permanence or evanescence of the
spot would indicate the sun or earth as being the locality of such
derangement. The more permanent form being developed at the sun, and the
more ephemeral at the earth.
Any forces in operation at the earth which might interfere with the
intercommunication of light, would lessen the brilliancy of the light,
at the earth-extremity of the cone-space; and the deficiency thus
produced would disclose to an observer at the earth all the appearances
of a spot upon the surface of the sun. The so-called spot, thus
produced, might therefore not be regarded as a veritable spot upon the
sun's disc, but rather as an optical illusion.
_They are Caused by Magnetic Perturbations._
What may be the forces in operation on the part of the sun, and earth
alike, which may so interfere with the development or transmission of
light through the solar cone-space?
The condition of the contents contained within the enclosure of the
sun-crust and earth-crust, is presumably one of unrest; its actions
varying from repose to the most violent agitation, with a tendency to
the cyclonic in its motions. Although the earth-core may not be presumed
to be an entire moving mass, yet it is known to be in a measure
incandescent, and molten. Magnetic storms occur within our earth-crust
which sway the needle without, and almost instantaneously manifest their
presence over areas of more than half the globe. The same phenomena are
undoubtedly present in increased development at the sun.
We may therefore with reason suppose that perturbations, however
produced, occur within those spheres, of such an extent and character as
might be a sufficient cause of the interruption of development, or of
transmission of that fluid.
_Inconsistency of the Present Accepted Philosophy._
The ephemeral or evanescent character of many of the so-called
sun-spots, removes them from the domain of sun-phenomena, otherwise than
in appearance.
_Figures that are Deceptive._
Some of these spots even of large dimensions come into the field of view
almost instantaneously; and as suddenly disappear. Thus KRONE "observed
a spot of no inconsiderable dimensions which sprang into existence in
less than a minute of time." DR. WOLLASTON says:--"I once saw with a
two-inch reflector a spot which burst in pieces as I was looking at it."
BIELA also notes that "spots disappear sometimes in a single moment."
SIR WILLIAM HERSCHEL "turned away his eyes from a group of spots he was
observing, and when he looked again the group had vanished."
Of those who attempt to make an estimate of these phenomena by
mathematical formulæ, we would ask, What velocities must these sudden
and apparently widespread outbursts represent, if they take place at the
sun?
_Effects of these Wonderful Phenomena._
That this phenomenon is a result of an interruption of the solar current
is rational to suppose. It is indisputable that the interruptions which
produce these manifestations have an important bearing upon terrestrial
phenomena. Winds, storms, vegetation, healthfulness, are manifestly
influenced, and in a measure controlled by these perturbations.
_Mistaken Conceptions._
The claim of many scientists that spot periods may be calculated, and
classified, possesses no element even of probability, much less of fact,
to sustain the supposition. The evanescent character of many of these
spots places them beyond the sphere of statistical calculation.
_May not be Tabulated._
Not even concerted and systematic investigation can insure reliable
conclusions, for persons separated by even inconsiderable distances
would not always observe precisely the same spot manifestations.
Moreover, the spots appear and vanish so quickly that no correct
estimate can be made at any single locality. As well attempt to map and
chart the aurora borealis.
_Unbiassed Estimate of their Character and Location._
SCHEINER was one of the first who ever observed these spots through a
telescope, and was therefore uncontrolled by theories in his estimate of
their character and location. He held it "impossible that they could be
on the sun itself," and imagined some of them to be "as far from the
sun, as the moon, Venus, or Mercury."