THE EARTH FRAME 



its shape. All worlds are round. Nature is 

 intent upon building for eternity, and it chooses 

 the strongest building principle of all the self- 

 supporting globe. 



We cannot see upon the globe itself the great, 

 sweeping lines that make the earth circle, but, 

 as intimated some chapters back, we may gain 

 some suggestion of them from certain sky 

 curves. The upward and inward arch of the 

 blue sky, the visible envelope of the earth, but 

 repeats the curve of the earth itself. Nothing 

 gives the feeling of the globe's rotundity so ef- 

 fectively as this ; and yet I have been told by 

 many observant people that they could not see 

 this curve of the heavens, that the blue looked 

 to them perfectly flat, and that the monotone 

 of the color, the brilliancy of the light, de- 

 stroyed all sense of form. Perhaps the curve 

 would be apparent to them if they saw it cast 

 upon the sky by the earth's shadow instead of 

 suggested in the illuminated blue. This can 

 be seen almost any summer evening, when the 

 sky is free of clouds and the sun has just fallen 

 below the horizon. Facing to the north and 

 looking at the zenith, we are aware of the light 

 slowly fading out of the west. Everyone sees 

 and knows that fading light, but few ^f us ever 



Earth linet. 



