296 HISTORY OF PHYSICAL ASTRONOMY. 



vations of the two Herschels on double stars, which 

 have led to acknowledgement of the law of the 

 revolution of such systems. But besides these, the 

 same illustrious astronomers have accumulated 

 enormous treasures of observations of Nebulae ; the 

 materials, it may be, hereafter, of some vast new 

 generalization with respect to the history of the 

 system of the universe (BA). 



