280 THYSICAL GEOGRArHY OF THE SEA, AND ITS METEOROLOGY. 



theless, the f^ictwas set forth as distinctly in the Book of Nature ' 

 as it is in the Book of Eevelation ; for the infant, in availing 

 itself of atmospherical pressure to draw milk from its mother's 

 breast, unconsciously proclaimed it. 



517. Tlie barometer under the cloud-ring. — The barometer* stands 

 lower under this cloud-ring than on either side of it (§ 3G2). 

 After having crossed it, the attentive navigator may perceive 

 how this belt of clouds, by screening the parallels over which he 

 may have found it to hang from the sun's rays, not only promotes 

 the precipitation -svhich takes place within these parallels at 

 certain periods, but how, also, the rains are made to change the 

 places upon which they are to fall ; and how, by travelling with 

 the calm belt of the equator up and down the earth, this cloud- 

 ring shifts the surface from which the heating rays of the sun 

 are to be excluded ; and how, by this operation, tone is given to 

 the atmospherical circulation of the world, and vigour to its 

 vegetation. 



518. Its motions. — Having travelled with the calm belt to the 

 north or south, the cloud-ring leaves a clear sky about the 

 equator; the rays of the torrid sun then pour down upon the 

 solid crust of the earth there, and raise its temperature to a 

 scorching heat. The atmosphere dances (§ 356), and the air is 

 seen trembling in ascending and descending columns, with busy 

 eagerness to conduct the heat off and deliver it to the regions 

 aloft, where it is required to give dynamical force to the air in 

 its general channels of circulation. The dry season continues; 

 the sun is vertical ; and finally the earth becomes parched and 

 dry ; the heat accumulates faster than the air can carry it away ; 

 the plants begin to wither, and the animals to perish. Then 

 comes the mitigating cloud-ring. The burning rays of the sun 

 are intercepted by it : the place for the absorption and reflection, 

 and the delivery to the atmosphere of the solar heat, is changed ; 

 it is transferred from the upper surface of the earth to the upper 

 surface of the clouds. 



519. Meteorological processes. — Eadiation from land and sea 

 below the cloud-belt is thus interrupted, and the excess of heat 

 in the earth is delivered to the air, and by absorption carried up 

 to the clouds, and there transferred to their vapours to prevent 



* Observations now show that the thermometer stands highest under th* 

 cloud-ring. Indeed, the indications ate that it coincides \Yith the thermal 

 e>j[uator. 



