Contents xxvii 



PAGE 



318-20. Laplace's nebular hypothesis in the light of 

 later discoveries: the sun's heat: Helmholtats 

 shrinkage theory. Influence of tidal friction on 

 the development of the solar system : Professor 

 Darwin's theory of the birth of the moon. 

 Summary 406 



LIST OF AUTHORITIES AND OF BOOKS FOR STUDENTS . .411 



INDEX OF NAMES 417 



GENERAL INDEX 425 



