A. MATHEMATICS AND ASTRONOMY. 39 



may consist of a more or less continuous sheet of descending 

 rain not of water, of course, but of the materials whose va- 

 pors are known to exist in the solar atmosphere. As this 

 tremendous rain descends, the velocity of all the falling drops 

 would be retarded by the resistance of the denser gases un- 

 derneath, and the drops would eventually coalesce until a 

 continuous sheet would result, and several of these sheets 

 uniting, would form a sort of bottomless ocean, resting upon 

 the compressed vapors below, and pierced by innumerable 

 jets and bubbles. N. Y. Tribune, October 31, 1873; Proe. 

 National Academy. 



THE ATMOSPHERE OF JUPITER. 



Dr. Lohse has investigated the velocity of the rotation of 

 the cloud layers of Jupiter at different degrees of latitude on 

 that planet. He finds that, in general, in the middle latitudes 

 of Jupiter, there is a greater stability in the upper strata of 

 the atmosphere than in the neighborhood of the equator, 

 where the velocity of the rotating masses is increased by 

 wind. He sees in this fact a probability that trade-winds 

 prevail there as upon our earth. 7 C\ X., 185. 



VISIBILITY OF THE DARK HALF OF VENUS. 



The fact that, occasionally, the dark half of the surface of 

 the planet Venus glimmers with a peculiar gray light is 

 one of the most interesting phenomena that is noted in con- 

 nection with the planets of our system. The records of the 

 numerous cases in which this phenomenon has been observed 

 have been collated by Dr. Safarik, from which it appears that 

 twenty-one different observers, and twelve of these more 

 than once, have noticed the phenomenon in question. More 

 than half of these observations belong to the last twelve 

 years, and he concludes that probably the phenomenon is 

 one of constant occurrence; that, indeed, it is the normal 

 condition of the planet, and can be seen at every inferior con- 

 junction, if only the planet be carefully watched, and with 

 sufficiently powerful telescopes. The earliest observation of 

 those collected by him is that made by Derham about the 

 year 1712. Bode, Meyer, William Herschel, and Schroeter are 

 among those who recorded this phenomenon in the last cent- 

 ury. The latest observations are those by Winnecke and 



