g of the companion object. While
semi-extinct, in 1882-84, it lost little motion; but a fresh access of
retardation was observed by Professor Young[1073] in connection with its
brightening in 1886. This suggests very strongly that the red spot is
_fed from below_. A shining aureola of "faculae," described by Bredichin
at Moscow, and by Lohse at Potsdam, as encircling it in September,
1879,[1074] was held to strengthen the solar analogy.

The conspicuous visibility of this astonishing object lasted three
years. When the planet returned to opposition in 1882-83, it had faded
so considerably that Ricco's uncertain glimpse of it at Palermo, May 31,
1883, was expected to be the last. It had, nevertheless, begun to
recover in December, and presented to Mr. Denning in the beginning of
1886 much the same aspect as in October, 1882.[1075] Observed by him in
an intermediate stage, February 25, 1885, when "a mere skeleton of its
former self," it bore a striking likeness to an "elliptical ring"
descried in the same latitude by Mr. Gledhill in 1869-70. This, indeed,
might be called the preliminary sketch for the famous object brought to
perfection ten years later, but which Mr. H. C. Russell of Sydney saw
and drew still unfinished in June, 1876,[1076] before it had separated
from its matrix, the dusky south tropical belt. In earlier times, too, a
marking "at once fixed and transient" had been repeatedly perceived
attached to the southernmost of the central belts. It gave Cassini in
1665 a rotation-period of nine hours fifty-six minutes,[1077] reappeared
and vanished eight times during the next forty-three years, and was last
seen by Maraldi in 1713. It was, however, very much smaller than the
recent object, and showed no unusual colour.[1078]

The assiduous observations made on the "Great Red Spot" by Mr. Denning
at Bristol and by Professor Hough at Chicago afforded grounds only for
negative conclusions as to its nature. It certainly did _not_ represent
the outpourings of a Jovian volcano; it was in no sense attached to the
Jovian soil--if the phrase have any application to that planet; it was
_not_ a mere disclosure of a glowing mass elsewhere seethed over by
rolling vapours. It was, indeed, certainly not self-luminous, a
satellite projected upon it in transit having been seen to show as
bright as upon the dusky equatorial bands. A fundamental objection to
all three hypotheses is that the rotation of the spot was variable. It
did