295 



March 8, 1855. 

 Sir BENJAMIN BRODIE, Bart., V.P., in the Chair. 



The following papers were read : 



I. " On the Perihelia and Nodes of the Planets." 

 By EDWARD J. COOPER, F.R.S. Received February 2, 1855. 



Prefatory to my volume on Cometic Orbits, published in 1852, I 

 invited the attention of astronomers to the several points of resem- 

 blance between the planetary orbits and those of periodic comets. 

 Among these it was shown, that of the heliocentric longitudes of 

 perihelia and ascending nodes of the then known planets and periodic 

 comets, two-thirds were situated in the heliocentric semicircle 

 between 315 and 135. The planets stood thus in quadrants 



o o 



L. P.'s between 45 and 135 = 



135 and 225 = 



225 and 315 = 



315 and 45 = 

 ft between 45 and 135 = 



135 and 225=4 



225 and 315 



315 and 45 = 



=41 



i = 4j 



Here the L. P.'s appeared as 16 to 7, and the ascending nodes as 

 14 to 8. Two additional asteroids were subsequently discovered 

 leaving the L. P.'s as 16 to 9, and the ascending nodes as 15 to 9. 

 Again, in 1853, I sent a note upon the same subject to the Royal 

 Astronomical Society of London. At that time a considerable addi- 

 tion had been made to the asteroids, and the total number of planets 

 had risen from 25 to 35. Following the same distribution of the 



