452 THE CHEMISTRY OF CREATION. 



The most remarkable and well defined oceanic 

 current is the Equatorial. The Trade- winds 

 were noticed to have a two-fold cause, the high 

 temperature of the tropics, and the revolution 

 of the earth. This great current of water is due 

 to the latter cause, and in part to the impulse 

 of the Trade-winds which blow in the direction 

 which it pursues for a large part of its course ; 

 namely, from east to west. This current is 

 very evident, both in the Atlantic and Pacific 

 Oceans, between the parallels of 30, on each 

 side of the equator, pursuing an average velocity 

 of from nine to ten miles a day. It is con- 

 nected with another system of currents called 

 the Polar. The direction of the latter is from 

 the poles toward the equator. A flow of water 

 in this direction is induced by two causes. In 

 the equatorial regions, in consequence of the 

 great power of the solar rays, a vast amount of 

 water is raised into the atmosphere by the force 

 of evaporation ; to supply this loss, a flow of 

 water sets in from the colder regions lying north 

 and south, and thus a current is produced. In 

 addition, the greater velocity of the earth at 

 the equator tends to draw the water from less 

 swiftly moving regions to that position, and 

 thus also a current is established. That such 

 a current, or system of currents actually exists, 

 cannot be doubted. The evidence of their 

 existence and power is found in the frequency 



