26 THE UNIVERSE 



to turn over, as a water-wheel is turned by the 

 swift current of a river. This vast stream or cur- 

 rent of invisible power, when it starts from the 

 photosphere of the sun, is 865,000 miles in diam- 

 eter and is narrowed to a focus of 8,000 miles at 

 the earth's surface, thus increasing its force and 

 power a thousand-fold. The largest river on the 

 earth is 180 miles wide at its mouth and about 

 3,000 miles long, but what an insignificant rivulet 

 it is in contrast with this vast, invisible, omnipotent 

 stream of electric life-giving power, constantly pass- 

 ing to and fro from sun to earth and from earth 

 to sun. 



Think of its marvelous speed ! While the swiftest 

 current of a river or the speed of a railroad train 

 is scarcely fifty miles an hour, this mighty electric 

 tide comes with the speed of light 186,000 miles a 

 second, or almost 12,000,000 of miles an hour; 

 and it turns the earth over at the rate of a thou- 

 sand miles an hour by its lines of magnetic force, 

 just as the swift tide of a river turns the water- 

 wheel of a mill. And that the earth may turn more 

 surely and steadily, it has vast mountain ranges 

 running north and south from its poles, such as the 

 Andes and the Himalayas on opposite sides of its 

 surface, and other ranges scattered between, to act 

 as extending flanges and paddles, like those on a 

 water-wheel, to enable this vast electric tide to turn 

 it more readily, and, like the brushes on an electric 

 dynamo, to generate and draw electric currents 

 from earth and sky, and moisture from the clouds, 

 to bless and fertilize the earth and make it the 

 theatre of man's life and activities. 



Beneath these mountain ranges and in the outer 



