Cometary Bodies and Satunis Rings. 745 



planetoids clearly indicate them as fragments of a large 

 planet, in accordance with the conclusions arrived at by 

 Olbers in 1802. The illustrious astronomer further assumed 

 that the orbits of all the fragments would intersect each 

 other at the point where the explosion occurred. Subsequent 

 observations have, however, shown (which I shall confirm 

 farther on) that this supposition, while applicable in many 

 instances, does not hold good as a generalization. 



It will now be evident, without further discussion, that 

 had the exploded major planet been a solid body throughout 

 as hard as steel, it would still be revolving in its orbit, and 

 would thus have deprived the world of an interesting chapter 

 of astronomical science. 



A review of the history of cometary astronomy brings out 

 the remarkable fact that, while much has been written on 

 the nature and motions of comets, few, if any, serious attempts 

 have been made to account for their origin. The general 

 opinion of modern astronomers, in accordance with the views 

 of Kant* and Laplace f, is that these bodies are strangers 

 to the solar system, which have been captured in the course 

 of their lawless wanderings from the depths of the stellar 

 universe. 



The principal objection to this supposition is the immense 

 distance of the solar system from the fixed stars. The best 

 determination of the distance of the nearest of them was 

 made by Dr. Gill at the Cape of Good Hope in 18N1, which 

 showed that a Centauri had a parallax of 0"'75, indicating a 

 distance of about 25 billion miles, or 9000 times more distant 

 from Neptune than that planet is from the sun. As the 

 attraction of gravitation at the orbit of Neptune is only one 

 forty-second millionth of that at the solar surface, the attrac- 

 tive force at the distance of the fixed stars may be considered 

 a negligible quantity in determining the motions of cometary 

 bodies having their origin in other planetary systems. 

 Granting for the moment that comets actually belong to 

 other stellar systems, the problem of their origin and forma- 

 tion would still present itself for solution to earnest inquirers 

 into the nature and causes of things. 



The discoveries in cometary astronomy, more especially 

 those of Schiaparelli, that the orbits of certain comets are 

 identical with those of well-known streams of meteors, as 

 instanced in the comets of Tempel and of Biela in relation 

 to the November meteors, clearly point to the conclusion 

 that the place of origin of these erratic bodies is within the 



* Kant's 'Natural History and Theory of the Heavens/ Chapter 3. 

 ! t Laplace's Systeme du Monde, 1824. 



