FROM 



NEBULA '*2 NEBUL 



OR 



THE DYNAMICS OF THE HEAVENS 



A BROAJ> OUTLINE OF THE HISTORY OF ASTRONOMY 



A GENERAL SUMMARY OF ITS ACHIEVEMENTS 



A SYNOPSIS AND CRITICISM: OF RECENT 



COSMOLOGICAL THEORIES 



AND 



AN EXPANSION OF THE PRINCIPLE OF UNIVERSAL 



GRAVITATION TO THE SOLUTION OF MANY 



COSMIC PROBLEMS HERETOFORE DEEMED 



INSOLUBLE 



BY 



GEORGE HENRY LEPPER 



MEMBER OF THE PITTSBURGH BAB 



FOURTH EDITION REVISED 4ND ENLARGED 



PRIVATTHL t 



BERGER BTJIIjDrNG, PITTSBURGH, PA. 

 1919 



