CHAPTER VI. 



THE SEASONS. 



Why their varying Temperature ? 



THE usual explanation of these phenomena, 

 i. #., the influence of direct and oblique sun- 

 rays, has ever seemed insufficient and unsatis- 

 factory ; especially in view of the. fact that 

 the heat comes not from the sun by continu- 

 ity after the manner of progression as from a 

 heated body. 



A philosophy more exact and consistent 

 may be found in the development of the 

 theory already advanced, and which is illus- 

 trated in the following plates. 



The maximum of heat at the surf ace of the 

 earth bears a very constant and intimate rela- 

 tion to the line of greatest diameters of the 

 sun and earth. PI. II. a. 



Through this line the heat-producing func- 

 tions of these great spheres are in operation 

 in the highest degree. 



