The brilliant Venus was certainly the first planet noticed by the ancients, as much on account of its brightness as its rapid motion. Hardly is the sun set than it sparkles in the twilight; from evening to evening it removes further from the west and increases in brightness; during several months it reigns sovereign of the skies, then plunges into the solar fires and disappears. It was pre-eminently the star of the evening, the shepherd’s star, the star of sweet confidences. It was the first of celestial beauties, and the names conferred upon it correspond to the direct impression which it produced on contemplative minds. Homer called it “Callistos,” the _Beautiful_; Cicero named it _Vesper_, the evening star, and _Lucifer_, the morning star, a name likewise given in the Bible and the ancient mythologies to the chief of the celestial army. The most ancient astronomical _observation_ we have of Venus is a Babylonian record of the year 685 B. C. It is written on a brick and preserved in the British Museum. The best hours for examining Venus in a telescope are those of daylight. In the night the irradiation produced by the brilliant light of this beautiful planet prevents us from distinguishing clearly the outlines of its phases. When Venus occupies the region of its orbit behind the sun, with reference to us—which is called the point of superior conjunction—it is at its greatest distance, and is reduced to a disk of 9½ seconds in diameter. It comes imperceptibly toward us, and when it passes its quadrature, at its mean distance, it presents the aspect of a half-moon. It soon attains its most brilliant light, at the epoch when it shines at a distance of 39° from the sun, and shows the third phase 69 days before its inferior conjunction. Its apparent diameter is then 40 seconds, and the width of its illuminated part is scarcely 10 seconds. In this position we see the fourth of the disk illuminated; but this quarter emits more light than the more complete phases. Finally, when it reaches the region of its orbit nearest to the earth, it shows us nothing more than an excessively thin crescent, since it is then between the sun and us, and presents to us, so to say, its dark hemisphere. This is the position where its apparent size is greatest, and it then measures 62 seconds in diameter. After passing its inferior conjunction the phases are reproduced, in inverse order, as a morning star. Venus is constantly visible in full daylight in astronomical instruments, even at the moment of its superior conjunction. It is then round and quite small. At the epochs of its inferior conjunction it presents itself under the form of a very thin crescent.