After the assurance that markings exist the next thing to arrest attention is that these markings move. The patches of color first made out by the observer are shortly found by him to have shifted in place upon the planet. And this not through mistake on his part but through method in the phenomena; for all do it alike. In orderly rotation the features make their appearance upon the body’s righthand limb (in the telescopic image), travel across the central meridian of the disk and vanish over its lefthand border. One follows another, each rising, culminating and setting in its turn under the observer’s gaze. A constantly progressing panorama passes majestically before his sight, new objects replacing the old with a march so steady and withal so swift that a few minutes will suffice to mark unmistakably the fact of such procession. But for all this ceaseless turning under his gaze, after a certain lapse of time it is evident that the same features are being shown him over again. With such recognition of recurrence comes the first advance toward acquaintance with the Martian world. For that in all their journeying their configuration alters not, proves them permanent in place, part and parcel of the solid surface of that other globe. This surface, then, lies exposed to view and by its turning shows itself subject, like our earth, to the vicissitudes of day and night. In such self-exposure Mars differs from all the four great planets, Jupiter, Saturn, Uranus and Neptune. Features, indeed, are apparent on the first two of these globes and dimly on the other two as well, but they lack the stability of the Martian markings. They are forever exchanging place. In the case of Jupiter what we see is undoubtedly a cloud-envelop through which occasional glimpses may possibly be caught of a chaotic nucleus below. With Saturn it is the same; and the evidence is that the like is true of Uranus and Neptune. What goes on under their great cloud canopies we can only surmise. With Mars, however, we are not left to imagination in the matter but so far as our means permit can actually observe what there takes place. Except for distance, which, through science, year by year grows less, it is as if we hovered above the planet in a balloon, with its various features spread out to our gaze below.