the spots on the sun are answerable. They
were first seen by the Jesuit Scheiner in 1611,
who showed them to his confidential pupils,
but dared not make his discovery public.
Having fully satisfied himself of their existence,
he consulted the Provincial of his Order, who
thus expressed his incredulity: "I have several
times read my Aristotle from beginning to end,
and I can assure you he mentions nothing of
the kind. Go, my son, and make your mind
easy. You may be certain that what you take
for spots on the sun are only defects in your
glasses or your eyes."

The first fruits of the discovery of the spots
was the determination of the sun's period of
revolution on his axis. Scheiner's observation
having been confirmed by Galileo, he at length
plucked up sufficient courage to announce it to
the world in a book entitled Rosa Ursina.

The spots on the sun are irregularly scattered
about the regions adjacent to his equator. Near
the poles, no trace of them is distinguishable.
They are constantly varying in form, and appear
in lesser or greater number, according to the
years. Their apparition even manifests a
certain degree of periodicity, and there would
seem to be a close connexion between their
production and certain terrestrial meteorological
phenomena.

The portion of the solar disk which is free
from spots is far from shining with equal
brightness. The ground is lightly carpeted with a
multitude of little black specks in a state of
continual change. When a spot is observed
with a high magnifying power, it is generally
found to have a dark nucleus, almost black,
surrounded by a greyish band, called the
penumbra, and then, round the penumbra, by
bands more brilliant than the rest of the
surface, and supposed by Sir John Herschel to be
the tops of immense waves which are symptoms
of the violent agitation going on in the upper
regions of the sun's atmosphere. The
dimensions of the spots are sometimes enormous,
their mouth being more than wide enough to
swallow the earth whole, without biting it.
The earth's diameter is only eight thousand
miles; and Herschel measured a spot whose
orifice was forty-two thousand five hundred
miles across.

It was not enough to discover the spots;
they had to be accounted for. Successive
astronomers did their best; and, at last, Arago
and the Herschels presented us with a
complete theory. Every spot, they say, is a hole
which penetrates from the outmost limits down
to the very surface of the sun. The black
nucleus we behold is the sun's soil or ground;
the penumbra is a stratum of opaque and
reflecting clouds; the brilliant bands constitute
a superficial, incandescent, and very luminous
atmosphere. With this set of atmospheres
disposed one over the other, one acting as a
screen, the other as an illuminator, and the
dark dense mass of the sun at the bottom of all,
the appearances of the spots are logically
explained. But however ingenious the hypothesis,
some people think it too complicated to be
true. The sun, they believe, is something
simpler than that.

Nevertheless, the whole of the machinery by
which the solar phantasmagoria is accomplished,
is on a scale worthy of the star in which it is
supposed to act. It is truly gorgeous and
magnificent. Admit a score of active volcanoes—
twenty score, a hundred score, or more, if needs
be. Their combined eruptions cannot fail to
rend the concentric atmospheres from top to
bottom, and to produce more or less considerable
holes. The inhabitant of the earth, peeping
through his telescope, will behold through
those cavities the dark ground of the sun,
which is the nucleus of the spot; the penumbra,
which is the stratum of heat-resisting
clouds; and then the bright faculæ, which are
tempest-waves of light in the photosphere. By
making the eruptions tear the solar atmospheres
in this way or that, you may account for every
possible appearance. The distinguished names
of the authors of this system forced it upon
the learned world in spite of the world's
incredulity. People are getting used to it now, and
yield it the assent of custom, if not of conviction.
Still, in astronomy, as well as in religion,
there exist certain sceptical Zulus who do not
implicitly take for granted everything they
read or hear.

M. Faye, an able French astronomer, in two
remarkable Memoires, has collected fresh facts
which deserve attention. A brief summary of
their purport has been given by M. de Parville,
in the Constitutionnel newspaper. Our readers
may perhaps remember our recent mention of
Spectral Analysis.* By dissecting light,
Messieurs Bunsen and Kirchhoff discovered the
means of ascertaining the substances contained
in the source of that light. Brilliant and
characteristic stripes, appearing in the prismatic
spectrum, announced the presence of such and such
metals. Each metal gives its own proper stripe,
about which there is no mistake. This happens
in the case of flame.
* See Photological Facts, chapter i., No. 307, p. 149.

But if, behind the flame, there be placed a
solid luminous source, like the electric light, for
instance, the brilliant and coloured stripe which
the metal gave is immediately replaced by a
black stripe occupying exactly the same
position.

Now, the spectrum of the sun's light is literally
riddled and cut up by black stripes, whose
signification was a puzzle, until the above
experiment taught that each black stripe betrayed the
presence of a metal. Nothing, therefore,
appeared more simple than, by consulting this
natural register, to find out what metals are
contained in the sun. Pursuing this singular
method with great practical minuteness of
research, Kirchhoff detected the following metals
in the solar atmosphere: Sodium (the base of
soda), calcium (the base of lime), magnesium (of
magnesia), baryum, iron, chrome, nickel, copper,