CHAPTER VIII.

ON LUNAR CRATERS. 89 Use of term Crater for Terrestrial and Lunar Formations—Truly Volcanic Nature of Lunar Craters—Terrestrial and Lunar Volcanic Areas compared—Similarity—Difference only in Magnitude—Central Cone—Found in great and small Lunar Craters—Formative Process of Terrestrial Volcanoes—Example from Vesuvius—Vast Size of Lunar Craters—Reasons assigned—Origin of Moon’s Volcanic Force—Aqueous Vapour Theory untenable—Expansion upon Solidification Theory—Formative Process of a Lunar Crater—Volcanic Vent—Commencement of Eruption—Erection of Rampart—Hollowing of Crater—Formation of Central Cone—Of Plateau—Various Heights of Plateaux—Coneless Craters—Filled-up Craters—Multiple Cones—Craters on Plateau—Double Ramparts—Landslip Terraces—Rutted Ramparts—Overlapping and Superposition of Craters—Source-Connection of such—Froth-like Aggregations of Craters—Majestic Dimensions of Larger Craters