in August, 1892:
"The great red spot is still visible, but it has just passed through a
crisis that seemingly threatened its very existence. For the past month
it has been all but impossible to catch the feeblest trace of the spot,
though the ever-persistent bay in the equatorial belt close north of it,
and which has been so intimately connected with the history of the red
spot, has been as conspicuous as ever. It is now, however, possible to
detect traces of the entire spot. An obscuring medium seems to have been
passing over it, and has now drifted somewhat preceding the spot."[1084]

The object is now always inconspicuous, and often practically invisible,
and may be said to float passively in the environing medium.[1085] Yet
there are sparks beneath the ashes. A rosy tinge faintly suffused it in
April, 1900,[1086] and its absolute end may still be remote.

The extreme complexity of the planet's surface-movements has been
strikingly evinced by Mr. Stanley Williams's detailed investigations. He
enumerated in 1896[1087] nine principal currents, all flowing parallel
to the equator, but unsymmetrically placed north and south of it, and
showing scant signs of conformity to the solar rule of retardation with
increase of latitude. The linear rate of the planet's equatorial
rotation was spectroscopically determined by Belopolsky and Deslandres
in 1895. Both found it to fall short of the calculated speed, whence an
enlargement, by self-refraction, of the apparent disc was
inferred.[1088]

Jupiter was systematically photographed with the Lick 36-inch telescope
during the oppositions of 1890, 1891, and 1892, the image thrown on the
plates (after eightfold direct enlargement) being one inch in diameter.
Mr. Stanley Williams's measurements and discussion of the set for 1891
showed the high value of the materials thus collected, although much
more minute details can be seen than can at present be photographed. The
red spot shows as "very distinctly annular" in several of these
pictures.[1089] Recently, the planet has been portrayed by Deslandres
with the 62-foot Meudon refractor.[1090] The extreme actinic feebleness
of the equatorial bands was strikingly apparent on his plates.

In 1870, Mr. Ranyard[1091]--whose death, December 14, 1894, was a
serious loss to astronomy--acting upon an earlier suggestion of Sir
William Huggins, collected records of unusual appearances on the disc of
Jupiter, with a view to investigate the questio