We have before us such a wealth of detail that the only trouble is to choose what to speak of where every point has something to demand attention, and we can only give here the briefest reference to the principal features. The most prominent of these is the great crater “Plato,” which lies in the lower right-hand part of the cut. It will give the reader an idea of the scale of things to state that the diameter of its ring is about seventy miles; so that he will readily understand that the mountains surrounding it may average five to six thousand feet in height, as they do. The sun is shining from the left, and, being low, casts long shadows, so that the real forms of the mountains on one side are beautifully indicated by these shadows, where they fall on the floor of the crater. In the lower part of the mountain wall there has been a land-slide, as we see by the fragments that have rolled down into the plain, and of which a trace can be observed in our engraving. The whole is quite unlike most terrestrial craters, however, not only in its enormous size, but in its proportions; for the floor is not precipitous, but flat, or partaking of the general curvature of the lunar surface, which it sinks but little below. I have watched with interest in the telescope streaks and shades on the floor of Plato, not shown in our cut; for here some have suspected evidences of change, and fancied a faint greenish tint, as if due to vegetation, but it is probably fancy only. Notice the number of small craters around the big one, and everywhere on the plate, and then look at the amazingly rugged and tumbled mountain heaps on the left (the lunar Alps), cut directly through by a great valley (the valley of the Alps), which is at the bottom about six miles wide and extraordinarily flat,--flatter and smoother even than our engraving shows it, and looking as though a great engineering work, rather than an operation of Nature, were in question. Above this the mountain shadows are cast upon a wide plain, in which are both depressed pits with little mountain (or rather hill) rings about them, and extraordinary peaks, one of which, Pico (above the great crater), starts up abruptly to the height of eight thousand feet, a lunar Matterhorn.