154 THE WEATHER, AND WEATHER PROPHETS. 



happens that in the course of ages the whole ocean has 

 not been transferred by this sort of distillatory process 

 from the tropics to the poles ; leaving the former dry, 

 and piling the latter with mountainous accumulations of 

 ice. Were the Polar regions of the globe occupied 

 by land instead of by sea, there is every reason to be- 

 lieve that such would be the case. As it is, the contrary 

 arrangement prevails, and the Polar snows fall upon 

 these seas or upon their frozen surfaces, and form float- 

 ing masses of ice, which are partly broken up and drifted 

 away, and partly melted in situ by currents of water per- 

 petually streaming in against and beneath them from 

 warmer regions, and thus become restored to the general 

 ocean. 



(17.) But what, it will be asked of course, produces 

 these warm currents 1 And how is the water of which 

 that snow consists, and all the rain which falls and feeds 

 the rivers that restore it to the sea, raised into the air, 

 and distributed over the world, and thrown down again 

 indiscriminately over all its surface? Common sense 

 assures us that all the rain, &c., which falls from the 

 skies must have originated in the sea, and must (if the 

 present state of things is to endure) find its way back to 

 it. But how is it done ? And, in the first place, where 

 are we to look for the motive power 1 ? To this the 

 answer presents itself at once. In the sun's heat. Any 

 of our readers who will take the trouble to refer to Lect. 

 II., 23, will find that the amount of solar heat which 

 actually reaches the surface of our globe would suffice to 

 melt an inch in thickness of ice in two hours thirteea 



