AMERICAN 



JOURNAL OF SCIENCE AND ARTS. 



[THIRD SERIES.] 



Art. LYl^On Jupiter and its Satellites ; by Maria Mitchell, 

 Professor of Astronomy in Vassar College. (With a plate.) 



The observations referred to in the following notes were 



made at a time when the mechanism of the instrument m use 



receiving improvements, and the records are therefore those 



ye estimates and not of accurate measurements. They do 



not, however, rest wholly on my own impressiona Separate 

 drawings and estimates were made in several cases by three oi 

 my students, Misses Abbot, Glover, and Mead, and my own 

 were checked by theirs. ^ -^ -o A\^ 



The characteristics of the phenomena seen on J ^ter s oisc 

 in the FaU of 1870 and the Winter of 1870-71 differed from 

 those of the preceding year. The rosy tinge of tb^ equatorial 

 belt was less marked ; the dark spots on the same belt were less 

 decided, and the white spots more numerous, in ^^^ no^ 

 Jan. 9, 1870, 1 use the expression » veiy rosy '' m describing the 

 upper edge of the broad belt ; words which I could ^otj^'^ 

 regard to the color, at any time of observation since that data 



The instrument used was the large Equatorial telescope, the 

 object-glass of which is 12^ inches in diameter. 

 . The oval marking given in fig. 1 was seen JaiL 1»; J°;!^V ;^ 

 IS without doubt the sime seen by Prof. Mayer at ^n earlier data 



It is at least a singular coiucidence, that a group of small 

 spots on the sun, arranging themselves m the same ^^^^f "^^ 

 eorded on Jan. 22. I LIrd on June 18, .l^^O, ^/^^^ tm^^^^^ 

 tbe extreme northern edge of Saturn's nng; the mght being 

 remarkably good. 



Am. Joxjb. Sci.— Third Series, Vol. I, No. 6.--Jdnk, 1871. 



