Manchester Memoirs, Vol. Iv. (1910), No. \. 



I. On the Origin of Cometary Bodies and Saturn's 

 Rings. 



By Henry Wilde, D.Sc, D.C.L., F.R.S. 



Received and read Ociobcr 4th, igio. 



As the first Halley Lecture which 1 delivered before 

 the University of Oxford in May last* contained some 

 matters new to astronomical science, it has appeared to 

 me that an abridgment of the lecture, with some additions 

 which have since presented themselves to me, would be of 

 value in continuation of my papers recently published by 

 the Society.f 



While the principle of dualism is abundantly manifest 

 in every department of knowledge and fully recognized in 

 the attractions and repulsions in molecular physics, the 

 phenomena of the repulsive energy of celestial bodies have 

 so far been unduly obscured by the more general principles 

 of moving force and the attraction of gravitation. 



The doctrine that the solar system, as at present 

 constituted, was formed by the successive condensations 

 of a nebular substance rotating about a central position, 

 has been more firmly established during recent years 

 through the great advances made in stellar photography, 

 by which many of the nebula; are visualized in various 

 stages of evolution as right- and left-handed spirals, and 

 clearly indicating the direction of their revolutions.;!: 



* Clarendon Press. Frowclc. 19 1 o. 



t Manchester Memoirs, vols. 53, 54, 1909, 1910. 



Phil. Mag. (6), vols. 18, 19, 1909, 1910. 

 X "Celestial Photographs," by Isaac Roberts, F.R.S. Vols, i, 2, 1893. 

 1899. 



November iit/i, igio. 



