36] NOTE ON WILLIAM BALL'S OBSERVATIONS OF SATURN. 285 



In a postscript is the following, with the little sketch : 



"I saw i? this morn, at 4 a clock with 12 foot glasse and judge him 



the same figure as in -64 that is just ovall with two black spotts and 



I thinke a faint shadow of a belt which I have alwaies seene, but will 

 not be peremptory in itt." 



The second letter is dated "Mamhead i? September 15, -66," and is 

 addressed "For Sir Robert Moray K' at Whitehall, These." 



" I designe to send you all the figures of i? . I promised them my 

 L d Brounker and hee was pleased most kindly to accept itt but I (like 

 any thing you please to call mee bad enough) have hitherto shamfully failed, 

 as alsoe of an account of husbandry to Mr Oldenburg. I am still gazing 

 at the starrs though to very little purpose more then to keep my eyes 

 in use," &c. &c. 



It will be noticed that the passage in Ball's first letter in which he 

 claims to be unbiased by any hypothesis, agrees with the statement of 

 Huyghens respecting him. 



The passage in the same letter, " for the shadow of the body on his 

 ring I doe not well understand the meaning but I suppose I saw the 

 same thing," I conjecture to refer to an attempted explanation by Huyghens, 

 or some other astronomer, of the phenomenon observed by Ball, by attri- 

 buting it to the shadow of the body of the planet cast on his ring. 



It is plain that such an explanation would not be applicable, if similar 

 depressions had been observed at .the two extremities of the minor axis 

 of the ring. 



