543 



XVII. " On the Perihelia and Nodes of the Planets." By 

 EDWARD J. COOPER, Esq., F.R.S. (Second Communi- 

 cation.) Received June 10, 1857. 



Early in the year 1855 I had the honour to transmit to the Royal 

 Society a paper on the distribution of the perihelia and ascending 

 nodes of the then discovered planets, which was read at the meeting 

 of the Society held on the 8th of March in that year. In that 

 paper I called attention to my first notice of the phenomena in the 

 Preface to my little work on Cometic Orhits. 



Ten asteroids having been since added to the number, I requested 

 my first assistant, Mr. Graham, to include them in a new distribution 

 of the perihelia and nodes, and he has just reported to me the results. 

 Instead, however, of following precisely the same semicircles which 

 I adopted, he referred in the first instance to the larger planets, with 

 a view to ascertain whether or not in the small planets there were 

 an apparent preference for the heliocentric semicircles in which the 

 perihelia and nodes of the majority of the larger planets are found. 

 Thus, 



For large Planets. 



Longitude of Perihelion, 1856-0. 

 7 from 12 1' to 168 19' 

 1 at 333 24' 



Longitude of ascending Nodes. 

 7 from 46 36' to 130 12' 

 elsewhere 



Middle point of Arc containing greatest number. 

 90 10' 88 24' 



Mean of these 89 17' 



Taking this : n round numbers=90, and dividing the asteroids 

 into three groups in the order of their discovery, we have 



