xvi CONTENTS. 



SECTION XXXVI. 



The Fixed Stars Their Number The Milky Way Double Stars 

 Binary Systems Their Orbits and Periodic Times Colours of the 

 Stars Stars that have vanished Variable Stars Variation in Sun's 

 Light Parallax and Distances of the Fixed Stars Masses of the Stars 



Comparative Light of the Stars Proper Motions of the Stars 

 Apparent Motions of the Stars Motion and Velocity of the Sun and 

 Solar System The Nebulae Their Number Catalogue of them 

 Consist of Two Classes Diffuse Nebulae Definitely formed Nebulae 



Globular Clusters Splendour of Milky Way Distribution of the 

 Nebulas The Magellanic Clouds Nebulae round n Argus Consti- 

 tution of Nebulae, and the Forces that maintain them Meteorites and 

 Shooting Stars Page 384 



SECTION XXXVII. 



Diffusion of Matter through Space Gravitation Its Velocity Sim- 

 plicity of its Laws Gravitation independent of the Magnitude and 

 Distances of the Bodies Not impeded by the intervention of any 

 Substance Its Intensity invariable General Laws Recapitulation 

 and Conclusion . . 424 



NOTES 429 



INDEX .. ,. 479 



