Venus, surrounded by a highly dense and rarefied atmosphere, which increases the difficulties of observing her surface, might be called the twin sister of the Earth, so similar are the dimensions of the two worlds. But, strange as it may seem to the many admirers, who are ready to hail in her an abode of joy and happiness, it is most probable that this planet, attractive as she is at a distance, would be a less desirable habitation than our floating island. In fact, the atmosphere of Venus is perpetually covered with cloud, so that the weather there must be always foggy. No definite geographical configuration can be discovered on her, despite the hopes of the eighteenth-century astronomers. We are not even sure that she rotates upon herself, so contradictory are the observations, and so hard is it to distinguish anything clearly upon her surface. A single night of observation suffices to show the rotation of Mars or of Jupiter; but the beautiful Evening Star remains obstinately veiled from our curiosity. Several astronomers, and not the least considerable, think that the tides produced by the Sun upon her seas, or globe in its state of pristine fluidity, must have been strong enough to seize and fix her, as the Earth did for the Moon, thus obliging her to present always the same face to the Sun. Certain telescopic observations would even seem to confirm this theoretical deduction from the calculations of celestial mechanics. The author ventures to disagree with this opinion, its apparent probability notwithstanding, because he has invariably received a contrary impression from all his telescopic observations. He has quite recently (spring of 1903) repeated these observations. Choosing a remarkably clear and perfectly calm atmosphere, he examined the splendid planet several times with great attention in the field of the telescope. The right or eastern border (reversed image) was dulled by the atmosphere of Venus; this is the line of separation between day and night. Beneath, at the extreme northern edge, he was attracted on each occasion by a small white patch, a little whiter than the rest of the surface of the planet, surrounded by a light-gray penumbra, giving the exact effect of a polar snow, very analogous to that observed at the poles of Mars. To the author this white spot on the boreal horn of Venus does not appear to be due to an effect of contrast, as has sometimes been supposed. Now, if the globe of Venus has poles, it must turn upon itself. Unfortunately it has proved impossible to distinguish any sign upon the disk, indicative of the direction and speed of its rotary movement, although these observations were made, with others, under excellent conditions.--Three o'clock in the afternoon, brilliant sun, sky clear blue, the planet but little removed from the meridian--at which time it is less dazzling than in the evening.