146 Things not generally Known. 



jfleteorologtcal 



THE ATMOSPHERE. 



A PHILOSOPHER of the East, with a richness of imagery truly 

 oriental, describes the Atmosphere as " a spherical shell which 

 surrounds our planet to a depth which is unknown to us, by 

 reason of its growing tenuity, as it is released from the pres- 

 sure of its own superincumbent mass. Its upper surface can- 

 not be nearer to us than 50, and can scarcely be more remote 

 than 500, 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 softest 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 sufficient to level the most stately forests 

 and stable buildings with the earth 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 vapours 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 are required. It bends the rays of the sun 

 from their path to give us the twilight of evening and of dawn ; 

 it disperses and refracts their various tints to beautify the ap- 

 proach and the retreat of the orb of day. But for the atmosphere 

 sunshine would burst on us and fail us at once, and at once 

 remove us from midnight darkness to the blaze of noon. We 

 should have no twilight to soften and beautify the landscape ; 

 no clouds to shade us from the searching heat ; but the bald 

 earth, as it revolved on its axis, would turn its tanned and 

 weakened front to the full and unmitigated rays of the lord of 

 day. It affords the gas which vivifies and warms our frames, 

 and receives into itself that which has been polluted by use 

 and is thrown off as noxious. It feeds the flames of life exactly 

 as it does that of the fire it is in both cases consumed and 

 affords the food of consumption in both cases it becomes 

 combined with charcoal, which requires it for combustion and 

 is removed by it when this is over." 



