On the latter, markings and streaks of strange variety suggested, if they failed-to prove, the existence of frequent spiral storms, disturbing, probably at an immense height above the surface, clouds which must be utterly unlike the clouds of Mars or the Earth in material as well as in form and mass.

These markings enabled us to follow with clear ocular appreciation the rapid rotation of this planet.

In the course of half-an-hour several distinct spots on different belts had moved in a direct line across a tenth of the face presented to us--a distance, upon the scale of the gigantic image, so great that the motion required no painstaking observation, but forced itself upon the notice of the least attentive spectator.

The belief of Martial astronomers is that Jupiter is not by any means so much less dense than the minor planets as his proportionately lesser weight would imply.

They hold that his visible surface is that of an enormously deep atmosphere, within which lies, they suppose, a central ball, not merely hot but more than white hot, and probably, from its temperature, not yet possessing a solid crust.