102 BULLETIN OF THB 



■THE SHADOW OF THE BALL OF SATURN PROJECTED ON THE RINGS, 



describing experiments made with an accurate drawing of Saturn 

 and its rings. The line of tlie projection of the shadow appeared 

 convex towards the planet, straight or concave according to the 

 distance of the observer from the drawing. Five persons made 

 accordant drawings of the appearance, independently of each 

 other. 



Mr. Asaph Hall made remarks on 



A bright spot which had RECENTLY BECOME VISIBLE ON THE 

 BALL OF SATURN. 



(abstract.) 



Mr. Hall stated that while observing one of the satellites of 

 Saturn on Dec. 7th, he noticed a round and well-defined spot on 

 the ball of the planet. The spot was 2" or 8" in diameter, and 

 was of a brilliant white color. It w^as situated a little north of 

 the rings, and in the direction of declination was near the middle 

 of the disk. The spot came to the centre of the disk in the 

 equator of rotation at &^ 18™ Washington m. t. The next day- 

 letters were sent to the astronomers of the country, and although 

 cloudy at Washington, the spot was observed on Dec. 10th by- 

 Professor Maria Mitchell at Yassar College observatory; by 

 Mr. Lewis Boss at Dudley observatory ; by Mr. D. W. Edgecomb 

 at Hartford, Conn., and by the Messrs. Clark at Cambridgeport, 

 Mass. The spot was again observed by Mr. Hall and Mr. 

 Eastman at Washington on Dec. 13th, and by Mr. A. G. Clark 

 at Cambridgeport ; and again by Mr. Hall at Washington on 

 Dec. 16th. 



From the observations thus far made it appears that the time 

 of Saturn's rotation, assuming that the spot has no proper mo- 

 tion, is id*' IS-^.O 

 This time, as given in the modern text-books, is 



lO'^ 29™ 16". 8 

 and is said to be Sir W. Herschel's last and corrected determina- 

 tion. On the other hand, the time of rotation published by Sir 

 W. Herschel in the Philosophical Transactions for 1794 is 

 lO"^ 16™ O'.U 



116th Meeting. January 13, 187T. 



The President in the Chair. 

 Forty-nine members and visitors present. 



