The interior of this fine crater presents striking examples of the concentric terrace-like formations that we have elsewhere assigned to vast landslip actions. Somewhat similar concentric terraces may be observed in other lunar craters; some of these, however, appear to be the results of some temporary modification of the ejective force, which has caused the formation of more or less perfect inner ramparts: what we conceive to be true landslip terraces are always distinguished from these by their more or less fragmentary character. On reference to Plate III., showing the full moon, a very remarkable and special appearance will be observed in a dingy district or zone immediately surrounding the exterior of the rampart of Tycho, and of which we venture to hazard what appears to us a rational explanation: namely, that as Tycho may be considered to have acted as a sort of safety-valve to the rending and ejective force which caused, in the first instance, the cracking of this vast portion of the moon’s crust—the molten matter that appears to have been forced up through these cracks, on finding a comparatively free exit by the vent of Tycho, so relieved the district immediately around him as to have thereby reduced, in amount, the exit of the molten matter, and so left a zone comparatively free from the extruded lava which, according to our view of the subject, came up simultaneously through the innumerable fissures, and, spreading sideways along their courses, left everlasting records of the original positions of the radiating cracks in the form of the bright streaks which we now behold. “WARGENTIN,” 26 (57·5—140·2). Plate XVII. This object is quite unique of its kind—a crater about 53 miles across that to all appearance has been filled to the brim with lava that has been left to consolidate. There are evidences of the remains of a rampart, especially on the south-west portion of the rim. The general aspect of this extraordinary object has been not unaptly compared to a “thin cheese.” The terraced and rutted exterior of the rampart has all the usual characteristic details of the true crater. The surface of the high plateau is marked by a few ridges branching from a point nearly in its centre, together with some other slight elevations and depressions; these, however, can only be detected when the sun’s rays fall nearly parallel to the surface of the plateau. To the north of this interesting object is the magnificent ring formation Schickard, whose vast diameter of 123 miles contrasts strikingly with that of the sixteen small craters within his rampart, and equally so with a multitude of small craters scattered around. There are many objects of interest on the portion of the lunar surface included within our illustration, but as they are all of the usual type, we shall not fatigue the attention of our readers by special descriptions of them. ARISTARCHUS, 176 (6·3—99·2), and HERODOTUS, 175 (63·2—99·6). Plate XVIII.