The examination of the lunar disc is therefore highly favorable for the study of the great geological phenomena of our own globe.

As certain astronomers have remarked, the Moon's surface, though older than the Earth's, has remained younger.

That is, it has undergone less change.

No water has broken through its rugged elevations, filled up its scowling cavities, and by incessant action tended continuously to the production of a general level.

No atmosphere, by its disintegrating, decomposing influence has softened off the rugged features of the plutonic mountains.