The reader may deem the picture a fancy sketch which possibly may not appeal to him. Nevertheless, it not only is possible, but one which has overtaken our nearest of neighbors. To this pass the Mater Amorum, Venus herself, has already been brought. She betrays it by the wrinkles which modern observation has revealed upon her face. Innocent critics, with a gallantry one would hardly have credited them,—which shows how one may wrong even the humblest of creatures,—have denied the existence of these marks of age, on the chivalrous _a priori_ assumption that it could not possibly be true because never seen before. Their negation, in naïve ignorance of the facts, partakes the logic of the gallant captain, who, when asked by a lady to guess her age, replied: “’Pon my word, I haven’t the slightest idea,” hastily adding, “But you don’t look it!” Less commendable than this conventional nescience, but unfortunately more to the point, is the evidence of prying scientific curiosity. Shrewdly divined as much as detected by Schiaparelli, made more certain by the crow’s-feet disclosed at Flagstaff, and corroborated by the testimony of the spectroscope there, her isochronism of rotation and revolution lies beyond a doubt. Attraction to her lord has conquered at last her who was the cynosure of all. Venus, in her old age, stares forever at the Sun, and we all know how ill an aging beauty can support a garish light. Mercury has been brought to a like pass. This was evident even before the facts came out about Venus, for Venus, true to her instincts, shields herself with a veil of air which largely baffles man’s too curious gaze. Mercury, on the other hand, offers no objection to observation. When looked for at the proper time, his markings are quite distinct, dark, broken lines suggesting cracks. Schiaparelli, again, was the first to perceive the true state of the case, and his observations were independently confirmed and extended at Flagstaff in 1896. In so doing the latter disclosed a very interesting fact. It was evident that the markings held in general a definite fixed position upon the illuminated part of the disk, showing that the planet kept the same face always to the Sun. But systematic observation, continued day after day for weeks, disclosed a curious shift, which, though slight, was unmistakable. Upon thought the cause suggested itself, and on being subjected to calculation proved equal to such accounting. In this singular systematic sway stood revealed the libration in longitude caused by the eccentricity of the planet’s orbit. [Illustration: DIAGRAM OF LIBRATION IN LONGITUDE DUE TO ROTATION.] [Illustration: _Mercury._ _Effect of Libration Rotation 88 days._]