The state of things this introduces to us upon that other world is to our ideas exceeding strange. It is not so much the slowness of the diurnal spin, eighty-eight times as long as our own, which is surprising, as the fact that this makes its day infinite in length. Two antipodal hemispheres divide the planet, the one of which frizzles under eternal sun, the other freezes amid everlasting night. The Sun does not, indeed, stand stock-still in the sky, but nods like some huge pendulum to and fro along a parallel of latitude. In consequence of libration the two great domains of day and night are sundered by a strip of debatable ground 23½° in breadth on either side, upon which the Sun alternately rises and sets. Here there is a true day, eighty-eight of our days in length from one sunrise to the next. But its day and night are not apportioned alike. The eastern strip has its daylight briefer than its starlight hours; the western has them longer. Nor are different portions of the strips similarly circumstanced in their sunward regard. Only the edge next perpetual day has anything approaching an equal distribution of sunlight and shade. The farther one just peeps at the Sun for a moment every eighty-eight days, and then sinks back again into obscurity. The transition from day to night is equally instantaneous and profound. For little or no twilight here prolongs the light; since the air, if there be any at all, is too thin to bend it to service round the edge to illuminate the night. When the libratory Sun sets, darkness like a mantle falls swiftly over the face of the ground. No evidence of atmosphere has ever been perceived, and theory informs that it should be nearly, if not wholly, absent. In consequence of the rigid uprightness of the planet’s axis, seasons do not exist. Their nearest simulacrum comes from the seeming dilatation of the Sun during half the year, and its apparent contraction during the other half. It expands so much between its January and its July as to receive more heat in the ratio of nine to four. A seasonless, dayless, and almost yearless planet, it is better to look at than to look from; but its study opens our eyes to the great diversity which even one of our nearest neighbors exhibits from what we take as matters of course on Earth.