_Obituary Notices_, p. 73.]

CHAPTER III

_PROGRESS OF KNOWLEDGE REGARDING THE SUN_

The discovery of sun-spots in 1610 by Fabricius and Galileo first opened
a way for inquiry into the solar constitution; but it was long before
that way was followed with system or profit. The seeming irregularity of
the phenomena discouraged continuous attention; casual observations were
made the basis of arbitrary conjectures, and real knowledge received
little or no increase. In 1620 we find Jean Tarde, Canon of Sarlat,
arguing that because the sun is "the eye of the world," and the eye of
the world _cannot suffer from ophthalmia_, therefore the appearances in
question must be due, not to actual specks or stains on the bright solar
disc, but to the transits of a number of small planets across it! To
this new group of heavenly bodies he gave the name of "Borbonia Sidera,"
and they were claimed in 1633 for the House of Hapsburg, under the title
of "Austriaca Sidera" by Father Malapertius, a Belgian Jesuit.[131] A
similar view was temporarily maintained against Galileo by the justly
celebrated Father Scheiner of Ingolstadt, and later by William
Gascoigne, the inventor of the micrometer; but most of those who were
capable of thinking at all on such subjects (and they were but few)
adhered either to the _cloud theory_ or to the _slag theory_ of
sun-spots. The first was championed by Galileo, the second by Simon
Marius, "astronomer and physician" to the brother Margraves of
Brandenburg. The latter opinion received a further notable development
from the fact that in 1618, a year remarkable for the appearance of
three bright comets, the sun was almost free from spots; whence it was
inferred that the cindery refuse from the great solar conflagration,
which usually appeared as dark blotches on its surface, was occasionally
thrown off in the form of comets, leaving the sun, like a snuffed taper,
to blaze with renewed brilliancy.[132]

In the following century, Derham gathered from observations carried on
during the years 1703-11, "That the spots on the sun are caused by the
eruption of some new volcano therein, which at first pouring out a
prodigious quantity of smoke and other opacous matter, causeth the
spots; and as that fuliginous matter decayeth and spendeth itself, and
the volcano at last becomes more torrid and flaming, so the spots decay,
and grow to umbrae, and at last to facul