ABSTRACT
The solar analogy of the rotation, varying with the latitude and being quickest at the equator, had been known as long ago as the time of Cassini, who even hinted at the similarity of Jupiter markings to sun-spots, a similarity more generally recognised since the careful and prolonged observations of Denning and others on the motion and appearance of the spots and belts. Soon afterwards Zellner, in 1865, rejecting the suggestions of Herschel and others that the bands and cloud movements on Jupiter were analogous to trade winds, which in a rapidly rotating body like Jupiter would have enormous effect, suggested that this analogy was misleading, since at such a distance the sun's effect in causing trade winds must be only 127th of that on the earth. He deduced that the requisite heat must come from within, and that Jupiter must be still a hot and almost gaseous body without a solid crust.
