390 T. C. CHAMBERLIN 



and so it seems probable that there may be a series of cases in 

 which the minor members of the couplets are dispersed with 

 different intensities into complete nebulae while the major mem- 

 bers only suffer varying degrees of eruptive action or partial 

 conversion into nebulae and so perhaps become stars with 

 nebulous adjuncts or atmospheres. Under this conception small 

 nebulae should be much more numerous than large ones. If 

 large hot planets, such as Jupiter is supposed to be, are poten- 

 tially gaseous, and if by disturbing approaches of stellar systems 

 such planets are thrown out of their allegiance to their primary 

 suns and take on comet-like courses, they would be specially 

 liable to disruption and dispersion into small nebulae, and would 

 augment the number of the latter. 



Whether the existing stellar movements and the mutual attrac- 

 tions of the stars are such as to give any substantial ground for 

 believing that close approach can be a <:/«>/ agency in producing 

 comets, meteorites, and nebulae, can only be determined when 

 some approximate knowledge of the dispersion, the masses, the 

 velocities, and the paths of the stars is gained. If the stars be 

 considered simply as so many scattered bodies flying through 

 space in straight lines at computed rates, and all mutual attrac- 

 tions and systematic relations be ignored, the frequency of dis- 

 turbing approaches would not seem to be great and the 

 quantitative value of the doctrine here sketched would seem to 

 be questionable. The solar system has certainly never been 

 subjected to disturbing approach since its present organization. 

 But the assumptions made are certainly not the true ones and 

 may not be representative. Besides the mere hazard of flying 

 bodies, the mutual attraction of two stars after they enter upon 

 each other's spheres of dominant influence — and these are very 

 large — increases notably the probabilities of a disturbing 

 approach even in the case of stars moving in opposed directions, 

 while in the case of stars moving in sub-parallel and gently con- 

 verging paths at sub-equal velocities, it may apparently become 

 a dominant factor. At the average computed distances of the 

 stars from each other, their mutual attractions are very slight, and 



