4 SCENERY OF THE HEAVENS. 



indicate great superficial inequalities in these regions, apparently similar to what would 

 be exhibited by the beds of the terrestrial oceans, if the waters were dissipated. Large 

 spaces of depression would then be laid bare, but of very unequal depth, varying from a 

 few fathoms to several miles. Are, then, the vast lunar cavities intended to cradle a 

 fluid element at some approaching epoch, or have they served that office, and' by some 

 physical change been deprived of it ? Have the billows rolled and sported in their depths 

 in by-gone time, or are they to come ? These are queries which observed appearances 

 naturally suggest, but we can grasp no certain conclusions. The aspect of the satellite is 

 however thought to favour the idea that the surface has not yet been water-worn that 

 the present stage of its history is parallel to that of the earth, before the sharp asperities 

 of its upheaved masses had been abrade'd by aqueous action, and smoothed by the detritus 

 which it deposits. It is a striking peculiarity of these districts that they shine with 

 various hues, from the grey tints of the Oceanus Procellarum to the beautiful green of 

 Mare Tranquillitatis, and the dark tracts of Plato. This diversity of colour proceeds, 

 doubtless, from some difference of substance ; and to distant observers of our own world, 

 its chalk, red-sandstone, and granite formations may be supposed to present a similar 

 diverse aspect, as well as the golden sands of Africa in contrast with the grey masses 

 of the Alps, the white cliffs of England, and the green prairies of America. 



The lunar mountains may be ranged into several distinct classes. Isolated peaks occur 

 in great numbers upon the surface. These are for the most part of a conical or sugar- 

 loaf form, rising with great abruptness, and attaining a considerable elevation. Pico, in 

 the neighbourhood of Plato, a little to the north, is one of the most distinct, remarkably 

 steep, upwards of seven thousand feet in height, as estimated by the length of its shadow. 

 The terrestrial rocks of an analogous character are the Peak of Teneriffe ; Pico, in the 

 Mauritius ; Adam's Peak, in the island of Ceylon ; and Mount Egmont, in New Zealand. 

 Of mountain-chains, there are several imposing specimens upon the face of the satellite, 

 the principal of which are the Apennines, a range running in a straight line from north- 

 east to south-west towards the centre of the disk, rising to the vast height of twenty 

 thousand feet. The chain may be seen casting long shadows upon the Mare Imbrium, of 

 which it forms the northern boundary, and from which the ascent is precipitous, being 

 more inclined upon the opposite side. Most of the terrestrial mountain-chains exhibit 

 this feature, for which it is difficult to account. The Alps descend more abruptly towards 

 Italy than Switzerland ; and the Pyrenees are steeper on the Spanish than on the French 

 side. The Ghauts of India are abrupt towards the west and slope towards the east ; while 

 the gigantic Andes precipitously rise from the sea-coast, and present an inclined face 

 towards the continent. But the most striking manifestations of lunar mountain scenery 

 are ring fences, or circular ramparts, enclosing plains and hollows of various diameter, the 

 more extensive having isolated peaks jutting from their bosom. Straight lines, angles, 

 and curves are described by terrestrial chains ; but no parallel is exhibited to the vast and 

 distinct annular ranges of the moon. The cones of our volcanoes are hollows unevenly 

 walled on all sides ; and the ring lunar mountains are of a similar construction, but upon 

 a grander scale. Many of these circular formations are, however, comparatively small, 

 and exhibit a decided crater-like character. Plato is a huge crater situated in a region 

 of great disturbance. Around Keppler the surface presents a less broken aspect, and is 

 remarkable for its brilliancy. Tycho and Copernicus are also fine specimens of lunar 

 craters. Streaky radiations of light appear issuing from them as from a centre, which 

 have been taken to be lava streams, but which are probably the illuminated summits of 

 elevated ridges. The dimensions of Aristarchus, thought to be an active volcano, are 

 computed to be a height of 2500 feet outside, and a depth of more than 7000 feet within. 



The present aspect of the satellite is thus decisive as to the past action of disturbing 



