§ 37, 38. THE SEA AND THE ATMOSPHERE. I3 



37. "The hurricanes which whirl with such fearful violence 

 Hurricanes. ovcr the surfacc, laising the waters of the sea to 

 enormous elevations, and submerging coasts and islands, attend- 

 ed as they are by the fearful attributes of thunder and deluges 

 of rain, seem requisite to deflagrate the noxious gases which have 

 accumulated, to commingle in one healthful mass the polluted el- 

 ements of the air, and restore it fitted for the ends designed for it. 

 We have hitherto dealt with the sea and air — the one the medium 

 through which the commerce of all nations is transported, the 

 other the means by which it is moved along — as themselves the 

 great vehicles of moisture, heat, and cold throughout the regions 

 of the world — the means of securing the interchange of these in- 

 estimable commodities, so that excess may be removed to where 

 deficiency exists, deficiency substituted for excess, to the un- 

 bounded advantage of all. This group of illustrations has been 

 selected because they are the most obvious, the most simple, and 

 the most intelligible and beautiful that could be chosen. 



88. " We have already said that the atmosphere forms a spheri- 

 Powers of the air. cal shcll, surrounding the earth to a depth which is 

 unknown to us, by reason of its growing tenuity, as it is released 

 from the pressure of its own superincumbent mass. Its upper 

 surface can not be nearer to us than fifty, and can scarcely be 

 more remote than five hundred miles. It surrounds us on all- 

 sides, yet we see it not ; it presses on us with a load of fifteen 

 pounds on every square inch of surface of our bodies, or from 

 seventy to one hundred tons on us in all, yet we do not so much 

 as feel its weight. Softer than the finest down, more impalpable 

 than the finest gossamer, it leaves the cobweb undisturbed, and 

 scarcely stirs the lightest flower that feeds on the dew it supplies ; 

 yet it bears the fleets of nations on its wings around the world, 

 and crushes the most refractory substances with its weight. When 

 in motion, its force is sufiicient to level with the earth the most 

 stately forests and stable buildings, to raise the waters of the ocean 

 into ridges like mountains, and dash the strongest ships to pieces 

 like toys. It warms and cools by turns the earth and the living 

 creatures that inhabit it. It draws up vapors from the sea and 

 land, retains them dissolved in itself or suspended in cisterns of 

 clouds, and throws them down again, as rain or dew, when they 

 arer equired. It bends the rays of the sun from their path to give 



