54 WHILE PLANETS MOVE, SUN WILL SHINE. 



As long as these mighty planets continue to 

 revolve, so long will the sun continue to shine. 

 The question of the source of solar light and 

 heat is therefore resolved simply into that of the 

 source of natural motive-power ; namely, the axial 

 rotation and orbital revolution of the heavenly 

 bodies. 



