ABSTRACT
Modern advances in planetary observation are confined to comparatively few channels, and the most attractive of these, in the case at any rate of the larger planets, has been the rotation. Schroer worked for thirty-four years at Lilienthal before the catastrophe of 1813, when French troops pillaged and destroyed the place and ruined the observatory, many of Schroer's manuscripts perishing in the conflagration of the Government offices. The planet next after Mercury in nearness to the sun is Venus, whose transits were considered of such importance in the problem of the solar parallax. Venus is considered to be much like the earth, not differing greatly in size and showing less equivocal traces of atmosphere than have been noted in the case of Mercury. Long-continued observations of the appearance of Venus have rendered it fairly certain that Venus has an atmosphere of considerable extent.
