CHAPTER NINE 



THE SUN 



O sun ! that o'er the western mountains now 



Go'st down in glory ! ever beautiful 



And blessed is thy radiance, whether thou 



Colorest the eastern heaven and night-mist cool, 



Till the bright day-star vanish, or on high 



Climbest and streamest thy white splendors from mid-sky. 



BRYANT 



OUR life depends upon the sun. It is the source of 

 light, heat, and power. Moonlight is but reflected 

 sunlight, and if the sky were packed full of moons they 

 would not afford us as much light as comes to us directly 

 from the sun. The light that reaches us from all the 

 stars is not nearly the millionth part of the light that 

 comes to us from the sun. We get some heat from the 

 interior of the earth, but it is not a thousandth part of 

 what we receive from the sun. When the sun is absent 

 for a night, the air becomes cooler ; and if it were to be 

 totally eclipsed for a week, all parts of the earth's sur- 

 face would become cold. 



Without sunlight green plants would not continue to 

 grow. Animals then would soon be without food, for 

 they cannot live indefinitely on one another. The fuel 

 that we burn would not have been formed without the 

 sun's rays to make things grow. Coal and gas were 

 formed from the remains of plants that lived long ago. 

 Even electric light and power are but transformed sun- 

 light. No wonder that men in all ages have worshiped 

 the sun. 



The size of the sun. The sun is more than a million 

 times as large as the earth. Its diameter is 866,000 



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