Some time ago, it was observed that situated at each pole of Mars there is a white patch, which increases and decreases at regular intervals. This had been observed for many years before the explanation was suggested by Herschel, that it was due to the freezing of the sea, and was exactly analogous to our Arctic and Antarctic Oceans. If this was true, the patch of ice would of course decrease in the Martial summer, and increase again as the winter came on. This was soon shown to be the fact. Thus we see that as far as regards the sea, Mars is very similar to our earth, with the exception, that the proportion of land is much larger. On the earth, the land is only about one-third of the area of the sea; while on Mars, the land and sea surfaces seem to be about equal in extent. The land is much cut up by the water, which exists not so much in the form of a few large oceans, but rather as a number of curious-shaped narrow inlets and channels, which intersect the continents in all directions. The bright red colour of the land is a curious fact, for which no adequate explanation has as yet been suggested. Herschel considered it was due to the peculiar nature of the soil; but it certainly seems curious that in this point Mars should differ from all the other planets. The appearance of the earth seen from a similar distance would probably be a dirty green, or perhaps brown. In fact, on the earth we have no soil or rock, which occurs in any quantity, of the red colour which we observe on Mars. There is therefore no vegetation, unless we adopt the curious theory, advanced by a French savant, that in Mars the foliage is red. Unluckily, we have no instrument that can at all help us here; the telescope and spectroscope are alike useless, and, for the present, we must content ourselves with vain conjectures.