THE STELLAR UNIYERSE 



FIRST LECTURE. 



Range of Vision. Augmented by the Telescope. Periodic Stars. Examples of this Class. 

 Various Hypotheses to explain these Appearances. Their Insufficiency. Temporary Stars. 

 Remarkable Examples of this Class. These may possibly be periodic Stars. Double Stars. 

 Their vast Number. They are physically connected. Telescopic Views of them. How they 

 may indicate the annual Parallax. Researches of Sir VV. Herschel. Discovery of the orbitual 

 Motions of double Stars. Binary Stars. Extension of Gravitation to the Stars. Their elliptic 

 Orbits discovered. Effects of double and coloured Suns. Proper Motions of tlie Stars. Prob- 

 able Motion of the Solar System. Analysis of its Effects. Suggestion of Mr. Pond. Indepen- 

 dent Motions of the Stars. Proper Motions of double Stars. Probable Amount of the real Mo- 

 tions of the Stars. 



