and Astronomical Notice^' 175 



the diverse emanations of the plants and animals belonging 

 to each ; to such an extent perhaps at last, as to prevent 

 human beings safely proceeding from one side of the world 

 to the other. 



By making the simple supposition, however, that the trades, 

 on rising at the equator, cross over to opposite poles, the 

 atmosphere is united in one grand whole, and every particle 

 in its turn courses over the whole extent of the earth'*s sur- 

 face, turning round one pole, and then in a sidelong path 

 crossing the equator and proceeding on to the other, turning 

 round that and returning again with a continual curvilinear 

 motion. 



To prove that such is really the case, Lieut. Maury brings 

 forward, /r*/, The greater quantity of rain in northern hemi- 

 sphere, although the southern may have such a very much 

 larger surface of water. Though no accurate experiments 

 have been made on the subject, still the fact cannot be 

 doubted, for the difference is so excessive, and it is too well 

 known to all our colonists in the southern hemisphere. Moun- 

 tain chains may doubtless have much to do with the deposi- 

 tion of rain, as, witness the unbroken fertility of China, though 

 extending through the same latitudes as Arabia and the 

 Sahara ; yet mountains will not alone explain the occurrence 

 of the Pampas of South America, in the same parallels as the 

 well- watered United States in the North, or the waterless 

 Australia as the counterpart of the Celestial Empire, and its 

 truly magnificent rivers. The extent, indeed, of ocean in 

 the south is such, that wherever land is found, it should be 

 inundated with rain, if this is to be furnished by the eva- 

 poration of southern seas ; but if northern seas furnish it, we 

 need wonder no more, particularly in the case of Australia 

 whose rain winds will have passed over central Asia, where 

 they could have obtained but little moisture ; while those of 

 North America, on the other hand, have been gathering 

 from the vast extent of the South Pacific Ocean. Thus the 

 watery wastes of the south seem to maintain the fertility of 

 the lands of the North, and the greater amount of evapora- 

 tion in the former, and of deposition in the latter, may serve 

 to explain another confessed but puzzling natural phenome- 



