We have seen that there are very grave doubts as to the existence of water on Mars. No doubt we have frequently spoken of the dark markings as "oceans" and of the bright parts as "continents." That this language was just has been the opinion of astronomers for a very long time. A few years ago Mr. Schaeberle, of the Lick Observatory, came to the very opposite conclusion. He contended that the dark parts were the continents and the bright ones were the oceans of water, or some other fluid. He pointed to the irregular shading of the dark parts, which does not suggest the idea of light reflected from a spherical surface of water, especially as the contrasts between light and shade are strongest about the middle of the disc. It is also to be noticed that the dark regions are not infrequently traversed by still darker streaks, which can be traced for hundreds of miles almost in straight lines, while the so-called canals in the bright parts often seem to be continuations of these same lines. Mr. Schaeberle therefore suggests that the canals may be chains of mountains stretching over sea and land! The late Professor Phillips and Mr. H.D. Taylor have pointed out that if there were lakes or seas in the tropical regions of Mars we should frequently see the sun directly reflected from them, thus producing a bright, star-like point which could not escape observation. Even moderately disturbed water would make its presence known in this manner, and yet nothing of the kind has ever been recorded. On the question as to the possibility of life on Mars a few words may be added. If we could be certain of the existence of water on Mars, then one of the fundamental conditions would be fulfilled; and even though the atmosphere on Mars had but few points of resemblance either in composition or in density to the atmosphere of the earth, life might still be possible. Even if we could suppose that a man would find suitable nutriment for his body and suitable air for his respiration, it seems very doubtful whether he would be able to live. Owing to the small size of Mars and the smallness of its mass in comparison with the earth, the intensity of the gravitation on the neighbouring planet would be different from the attraction on the surface of the earth. We have already alluded to the small gravitation on the moon, and in a lesser degree the same remarks will apply to Mars. A body which weighs on the earth two pounds would on the surface of Mars weigh rather less than one pound. Nearly the same exertion which will raise a 56-lb. weight on the earth would lift two similar weights on Mars.