MAGNITUDE OF THE ATMOSPHERE. 55 



occasional hurricanes in the West Indies, a few 

 large trees in a forest are unusual trophies of the 

 power of the tempest. The breezes which we 

 commonly feel are harmless messengers, travel- 

 ling so as to bring about the salutary changes of 

 the atmosphere; even the motion which they 

 communicate to vegetables tends to promote 

 their growth, and is so advantageous, that it has 

 been proposed to imitate it by artificial breezes 

 in the hothouse. But with a stream of wind 

 blowing against them, like three, or five, or ten, 

 gales compressed into the space of one, none of 

 the existing trees could stand ; and except they 

 could either bend like rushes in a stream, or ex- 

 tend their roots far wider than their branches, 

 they must be torn up in whole groves. We have 

 thus a manifest adaptation of the present usual 

 strength of the materials and of the workmanship 

 of the world to the stress of wind and weather 

 which they have to sustain. 



CHAPTER VI. 



The Constancy and Variety of Climates. 



IT is possible to conceive arrangements of our 

 system, according to which all parts of the earth 

 might have the same, or nearly the same, climate. 

 If, for example, we suppose the earth to be a 

 flat disk, or flat ring, like the ring of Saturn, re- 



