ASTRONOMY AND METEOROLOGY. 295 



COMETS OF 1867. 



Comet I. M. Stephan, director of the observatory at Marseilles, 

 discovered on the 22d of January a new comet, of considerable 

 brilliancy, generally round, and with a well-defined nucleus. The 

 train is supposed to be in line with the nucleus and the earth, and 

 therefore concealed. The nucleus appears denser on one side than 

 Uie other, leading to the supposition that the train is fan-shaped. 

 On Jan. 25th, at 8h. 53m. 35s. P. M., the right ascension was 2h. 

 33m. 53.5s.; north polar distance 74 26' ; hourly movement in. 

 right ascension -\- 5.17s. and in polar distance 1.29'. It is said 

 by Silloujelt to be periodical, and to be the same as Messier 1 s 

 comet of April, 1771. 



Comet II. A faint comet was discovered by Mr. Tempel at 

 Marseilles, on the 8d of April, 1867. 



The comet appeared to consist of a slightly oval coma, sur- 

 rounding a minute, not very bright, nucleus, which was not cen- 

 tral, but nearer to the following edge of the coma. The light of 

 the coma, as observed by Mr. Huggins, formed a continuous spec- 

 trum ; but he was unable to distinguish with certainty the spec- 

 trum of the light of the faint nucleus from the broad spectrum of 

 the coma on which it appeared projected ; he was not certain of 

 the presence of 2 or 3 bright lines. He considers it similar in 

 physical structure to Comet I., 1866. 



DIAMETERS OF THE ASTEROIDS. 



Mr. Stone has calculated the probable diameters of 71 asteroids, 

 determining their relative dimensions from their apparent bril- 

 liancy, assuming that their surfaces have equal reflective powers. 

 Adopting the diameters of Ceres and Pallas, as determined by 

 Herschel and Lamont, he converts their diameters into miles. 

 The following are the diameters of the 5 largest and the 5 smallest 

 asteroids : 



Vesta . . 214 miles. Themis . . 24 miles. 



Ceres . . 196 " Asia ... . 22 " 



Pallas . 171 " Maia . 18 " 



Juno . . 124 '' Atalanta . . 18 " 



Ilygeia . . 103 " Echo . . . 17 " 



NEW PLANETS IN 1867. 



Prof. Peters, at the Hamilton College Observatory, Clinton, New 

 York, discovered on the morning of July 7th, planet No. 92, or 

 the one hundredth primary member of the series. Its position 

 was in 21 hours and 21 minutes of right ascension, and 21 de- 

 grees and 31 minutes of southern declination. On the morning 

 of the 8th it was found to have moved, in 24 hours, about 25 sec- 

 onds to the west and 6 minutes to the south. Being of the elev- 

 enth magnitude and about one month before opposition with the 

 sun, the planet promises to be a bright one. This, the sixth discov- 

 ered by Prof. Peters, and at very nearly the same time by Prof. 

 Tietjen, of Berlin, has received the name of Undina. 



