faint oval ring, the rim remaining visible after the central part has
faded from sight.

One of the most remarkable phenomena connected with the mysterious spot
is a great bend, or scallop, in the southern edge of the south belt
adjacent to the spot. This looks as if it were produced by the spot, or
by the same cause to which the spot owes its existence. If the spot were
an immense mountainous elevation, and the belt a current of liquid, or
of clouds, flowing past its base, one would expect to see some such bend
in the stream. The visual evidence that the belt is driven, or forced,
away from the neighborhood of the spot seems complete. The appearance of
repulsion between them is very striking, and even when the spot fades
nearly to invisibility the curve remains equally distinct, so that in
using a telescope too small to reveal the spot itself one may discover
its location by observing the bow in the south belt. The suggestion of a
resemblance to the flowing of a stream past the foot of an elevated
promontory, or mountain, is strengthened by the fact, which was
observed early in the history of the spot, that markings involved in the
south belt have a quicker rate of rotation about the planet's axis than
that of the red spot, so that such markings, first seen in the rear of
the red spot, gradually overtake and pass it, and eventually leave it
behind, as boats in a river drift past a rock lying in the midst of the
current.

This leads us to another significant fact concerning the peculiar
condition of Jupiter's surface. Not only does the south belt move
perceptibly faster than the red spot, but, generally speaking, the
various markings on the surface of the planet move at different rates
according as they are nearer to or farther from the equator. Between the
equator and latitude 30° or 40° there is a difference of six minutes in