THE 



JOURNAL OF GEOLOGY 



JULY-AUGUST, igoi 



ON A POSSIBLE FUNCTION OF DISRUPTIVE APPROACH 

 IN THE FORMATION OF METEORITP:S, COMETS, 

 AND NEBULA. ^^ 



According to a familiar doctrine founded on the researches 

 of Roche, Maxwell, and others, a small body passing within a 

 certain distance (the Roche limit) of a larger dense body will be 

 torn into fragments by differential attraction. In reality, the 

 doctrine is applicable to the close approach of any two bodies 

 of sufficient mass and density, but, as this more familiar case of 

 a small body in close approach to a larger body is the one sup- 

 posed to be involved in the origin of comets and certain meteor- 

 ites, it will at first be taken as representative, and the wider 

 application of the doctrine will be considered later. 



The sphere defined by Roche's limit is computed on the 

 basis of a liquid body whose cohesion is negligible, and whose 

 self-gravitation alone is considered. It is obvious, therefore, 

 that when cohesion is a notable factor, a small body might pass 

 through the outermost part of this Roche sphere without suffer- 

 ing disruption, but that, if a nearer approach were made to the 

 large body, fragmentation might take place. There is, there- 

 fore, a sphere within the Roche limit — which may be called the 



' I am greatly indebted to Dr. F. R. Moulton for suggestions and criticisms, and 

 for formulse for certain auxiliary computations that do not appear in the paper. I 

 am under obligations to Mr. C. E. Siebenthal for the diagrams and other aid. 



^From The Astrophysical Journal, Vol. XIV, No. i, July 1901. 

 Vol. IX, No. 5. 369 



