Next was presented to our view on a somewhat smaller scale, because the area of the chamber employed would not otherwise have given room for the system, the enormous disc and the four satellites of Jupiter.

The difference between 400 and 360 millions of miles' distance is, of course, wholly unimportant; but the definition and enlargement were such that the image was perfect, and the details minute and distinct, beyond anything that Earthly observation had led me to conceive as possible.

The satellites were no longer mere points or tiny discs, but distinct moons, with surfaces marked like that of our own satellite, though far less mountainous and broken, and, as it seemed to me, possessing a distinct atmosphere.

I am not sure that there is not a visible difference of brightness among them, not due to their size but to some difference in the reflecting power of their surfaces, since the distance of all from the Sun is practically equal That Jupiter gives out some light of his own, a portion of which they may possibly reflect in differing amount according to their varying distance, is believed by Martial astronomers; and I thought it not improbable.

The brilliant and various colouring of the bands which, cross the face of the giant planet was wonderfully brought out; the bluish-grey around the poles, the clear yellowish-white light of the light bands, probably belts of white cloud, contrasted signally the hues--varying from deep orange-brown to what was almost crimson or rose-pink on the one hand and bright yellow on the other--of different zones of the so-called dark belts.