RED FOGS AND SEA BREEZES. 149 



the animals become torpid with cold, so here, under the influence 

 of the parching drought, the crocodile and the boa become 

 motionless and fall asleep, deeply buried in the dry mud. . . . 

 The distant palm-bush, apiDarcntly raised by the influence of the 

 con tact of unequally heated and therefore unequally dense strata 

 of air, hovers above the gi'ound, from which it is separated by a 

 narrow intervening margin. Half-concealed by the dense clouds 

 of dust, restless with the pain of thirst and hunger, the horses 

 and cattle roam around, the cattle lowing dismally, and the 

 liorses stretching out their long necks and snuffing the wind, if 

 haply a moist current may betray the neighbourhood of a not 

 wholly di'ied-up pool. ... At length, after the long drought, 

 the welcome season of the rain arrives ; and then how suddenly 

 is the scene changed ! . . . Hardly has the surface of the earth 

 received the refreshing moisture, when the previously barren 

 steppe begins to exhale sweet odours, and to clothe i tself with 

 killingias, and a variety of grasses. The herbaceous mimosas, 

 with renewed sensibility to the influence of light, unfold their 

 drooping, slumbering leaves to greet the rising sun; and the 

 early song of birds and the opening blossoms of the water-plants 

 join to salute the morning." 



327. Are the great deserts centres of circulation ? — The arid plains 

 and deserts, as well as high mountain ranges, have, it may well 

 be supposed, an influence upon the movements of the great 

 aerial ocean, as shoals and other obstructions have upon the 

 channels of circulation in the sea. The deserts of Asia, for 

 instance, produce (§ 299) a disturbance upon the grand system 

 of atmospherical circulation, which, in summer and autumn, is 

 felt in Europe, in Liberia, and away out upon the Indian Ocean, 

 as far as the parallel of the 10th degree of south latitude. There 

 is an indraught from all these regions towards these deserts. 

 These indraughts are known as monsoons at sea; on the land, as 

 the prevailing winds of the season. Imagine the area within 

 which this indraught is felt, and let us ask a question or two, 

 hoping for answers. The air which the indraught brings into 

 the desert places, and which, being heated, rises up there, 

 whither does it go ? It rises up in a column a few miles high 

 and many in circumference, we know, and we can imagine that 

 it is like a shaft many times thicker than it is tall ; but how is 

 it crowned ? Is it crowned like the stem of a mushroom, with 

 an efllorescence or ebullition of heated air flaring over and 



