When passing before the face of the sun, Venus appears as a round, black spot surrounded by an illuminated ring of atmosphere. The spectroscope has shown that this atmosphere is about the same as the earth's, possibly a little more dense, and, strange to say, there is now strong evidence that water vapor and oxygen are conspicuous by their absence. The dense atmosphere on Venus causes it to reflect light most beautifully but it also obscures its surface so that it is very difficult to see any markings. From time to time, when Venus passes between the sun and ourselves, it approaches to within 25 million miles of the earth, and even less--which is about 10 million miles closer than Mars comes at its nearest approach--yet we can clearly see the surface of Mars for its atmosphere is very tenuous, while the surface of Venus is almost completely hidden under thick white clouds. At such a time, Venus is also a slender crescent while Mars shows a full round face. The spectroscope combined with observations made upon such surface markings as may be seen in full daylight has, however, enabled us to determine that Venus rotates so slowly upon her axis that one face is always turned toward the sun. Thus the day on Venus must last forever and its night-side has only one long night. It has been conjectured that this condition may cause storms of frightful intensity upon its surface, for high air currents on the light torrid side probably flow rapidly to the dark, cold side, with the cold air near the surface of the dark, cold side flowing with equal rapidity to the torrid side. This state of affairs may tend to equalize the intensity of the two extremes of climate. Being almost 30 million miles closer to the sun than the earth, Venus may have a higher temperature than the earth, although the heat may be somewhat modified by the clouds which are always in the sky. Sometimes a faint, grayish light has been observed on the dark side of the planet when it is nearest the earth. This was at one time thought to be a reflection from a cold and frozen hemisphere, but a more likely suggestion hints that it may be an electrical manifestation in the planet's atmosphere, similar to our Aurora. Venus completes its orbit in 7½ months, its year being rather shorter than ours. The question of the existence of life not only on Venus, but on the other planets, is always a subject of general interest. Professor Barnard of the Yerkes Observatory had the following convictions on the subject: