2] OBSERVATIONS OF THE PLANET NEPTUNE. 53 



1847 



The star of reference throughout is No. 7648 of the British Association 

 Catalogue, the assumed mean place of which, January 1, 1846, determined 

 by 16 transit and 8 circle observations, is 



R. A. = 21 h 50 m 5 8 '91, N. P. D. = 103 23' 55"'56. 



I found the apparent diameter of the planet by micrometer measures 

 taken October 3 to be 3"'07. I have been able with the Northumberland 

 telescope to verify Mr Lassell's suspicion of a ring. I first received the 

 impression of a ring on January 12. Two independent drawings, made by 

 myself and my assistant, Mr Morgan, gave the same representation of its 

 appearance and position. The ring is very little open. Its diameter makes 

 an angle in the south preceding quadrant of 66 with the parallel of 

 declination, according to a measurement (not very satisfactorily taken) on 

 January 15. The ratio of the diameter of the ring to that of the planet 

 is by estimation that of 3 to 2. I am unable to account for my not 

 having noticed the ring earlier. 



