54 CALIFORNIA ACADEMY OF SCIENCES. 



reddish tinge. The seeing 41 and s Arietis as white stars 

 might militate against this view. But in M. Trouvelot's 

 great atlas of astronomical drawings, and in his drawings of 

 sim spots, in the Cambridge Annals, we can not help noth- 

 ing that his red spot on Jupiter is very brilliantly red as 

 compared with the appearance to most observers; and in 

 some of the sun spots we find a reddish tint added to the 

 blackness of the dark centres, the same reddish tint not be- 

 ing visible to other observers. It would be interesting for 

 M. Trouvelot to institute comparison with other observers 

 in order to settle this color question. 



At the meetings to the end of January, the President pre- 

 sented several verbal communications upon his observations 

 upon the planets and the Pons comet. 



THE PONS-1812, COMET. 



The comet was first seen at the Davidson Observatory with 

 the unassisted eye, on the first of December, before 8 hrs. in 

 the evening. A series of observations was made with the 

 6.4 inches equatorial to determine its position by compari- 

 sons with stars which were reasonably close to it. And a 

 series of six drawings was made at different dates, in Decem- 

 ber and January. The measures for position were made 

 with the micrometer for differences of declination, and over 

 the transit threads for differences of right ascension. At dif- 

 ferent times I was assisted by Messrs. T. D. Davidson and 

 C. B. Hill. 



The series of determinations embraces the dates: 1883, 

 December, 12, 14, 16, 18, 20, 22, 26, 27, 28, 29; 1884, Jan- 

 uary, 3, 9, 10, 11, 24, 25. There were several clear nights 

 upon which observations could not be made on account of 

 the path of the comet passing through a very barren part of 

 the heavens. After January 25th the long run of favorable 



