48 DETERMINATION OF THE ORBIT [2 



obtained on the meridian. All the above observations I have completely 

 reduced, and have placed the results at the disposal of Mr Adams for 

 deducing elements of the planet's orbit. 



On January 12, I had for the first time a distinct impression that the 

 planet was surrounded by a ring. The appearance noticed was such as would 

 be presented by a ring like that of Saturn, situated with its plane very 

 oblique to the direction of vision. I felt convinced that the observed elon- 

 gation could not be attributed to atmospheric refraction, or to any irregular 

 action on the pencils of light, because when the object was seen most 

 steadily I distinctly perceived a symmetrical form. My assistant, Mr Morgan, 

 being requested to pay particular attention to the appearance of the planet, 

 gave the same direction of the axis of elongation as that in which it 

 appeared to me. I saw the ring again on the evening of January 14. In 

 my note-book I remark, "The ring is very apparent with a power of 215, in 

 a field considerably illumined by lamp-light. Its brightness seems equal to 

 that of the planet itself." On that evening, Mr Morgan, at my request, 

 made a drawing of the form, which on comparison coincided very closely 

 with n drawing made independently by myself. The ratio of the diameter 

 of the ring to that of the planet, as measured from the drawings, is about 

 that of 3 to 2. The angle made by the axis of the ring with a parallel 

 of declination, in the south-preceding or north-following quarter, I estimated 

 at GO C . By a measurement taken with the position-circle on January 15, 

 under very unfavourable circumstances, this angle was found to be 65. I 

 am unable to account entirely for my not having noticed the ring at an 

 earlier period of the observations. It may, however, be said that an ap- 

 pearance like this, which it is difficult to recognize except in a good state 

 of the atmosphere, might for a long time escape detection, if not expressly 

 and repeatedly looked for. To force itself on the attention, it would require 

 to be seen under extremely favourable circumstances. Previous to the 

 observations in January, the planet had been hid for more than three 

 weeks by clouds. The evenings of January 12 and 14 were particularly good, 

 and the planet was at first looked at in strong twilight. Under very 

 similar circumstances I have twice seen with the Northumberland telescope 

 the second division of Saturn's King. 



I communicated to Mr Lassell of Liverpool, who was the first to suspect 

 the existence of a Ring, my observations upon it, accompanied with a 

 drawing ; and I have received from him in return a drawing of the 

 appearance presented in his twenty-feet reflector, closely resembling mine 



