THE 



GREAT PHYSICAL FORCES. 



CHAPTER L 

 INTRODUCTORY, 



The Sun. 



THE sun's position in the great field of 

 energy is daily becoming more exalted in the 

 estimation of philosophic minds. His labors 

 are being revealed to us with a distinctness 

 never before conceived. He it is that stored 

 the coal in the bosom of the earth, and piled 

 up the polar ice. He it is that aids the chem- 

 ist, drives the engine, ripens the harvest,, dis- 

 penses life and health. 



The study of the sun and solar physics, 

 therefore, must be essential to the right un- 

 derstanding of whatever we observe to take 

 place at the earth. Sun and earth are united 

 in indissoluble bonds. In philosophic minds 



