6 Wilde, Origin of Couietary Bodies and Satuni's Rings. 



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 1881, which showed that a Centauri had a 

 parallax of 075", indicating a distance of about 25 billion 

 miles, or 9,000 million miles 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 attractive 

 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 formation would still present itself for solution to 

 earnest inquirers into the nature and causes of things. 



The discoveries in cometary astronomy, more espe- 

 cially those of Schiaparelli, that the orbits of certain 

 comets are identical with those of well-known streams of 



■ Kant's " Natural History and Theory of the Heavens," Chap'er 3. 

 t Laplace's " Systeme du Monde," 1824. 



