Magnetism and the Trade Winds. 275 



descending in the calm zone of Cancer, it would first have to 

 remain a long time in contact with the sea, in order to be 

 supplied with vapour enough to fill the great rivers and 

 supply the rains for the whole earth between us and the 

 North Pole. 



In this case we should have an evaporating region on the 

 north as well as on the south side of this zone of Cancer ; 

 but the charts shew no such region ; I speak exclusively of 

 the ocean. 



Therefore I inferred that sf does not come out on the north 

 side of this calm zone, but on the south side ; thence to take 

 the circuit of the NE. trade winds, and to be replenished with 

 vapour ; and if it be admitted that such is the general course 

 of s' it must of necessity be admitted that 8" must re-appear 

 on the north side of this zone as the prevailing surface wind 

 which precipitates on its way to the Arctic regions, the resi- 

 duum or vapour that it has taken up in the trade-wind region, 

 and brought from the equatorial calms. 



Moreover, if 8" have the vapour which by condensation is 

 to water with showers the extra tropical regions of the 

 northern hemisphere ; nature, we may be sure, has provided 

 a guide for conducting 8" across this belt of calms and for 

 sending it on in the right way. Here it is that I saw the 

 foot-prints of an agent whose character I could not compre- 

 hend. It was this guide. 



Heat and cold, the early and the latter rain are not dis- 

 tributed over the earth by chance ; they are dispensed no 

 doubt according to design, and in obedience to laws that are 

 as certain and as sure in their operations as the morning stars 

 in their songs of praise. 



If there were really a general mingling in the calms of 

 Cancer, of the atmosphere which comes from the north with 

 that which comes from the south — of the moist and the dry 

 air as it descends here to the surface of the earth — if it de- 

 pended upon chance whether the dry air should come out on 

 this side, or on that, of the calms of Cancer ; — or whether the 

 moist air should return whence it came or not ; — if such were 

 the case in nature, we perceive that so far from any regularity 

 as to seasons, we should have, or might have, years of droughts 



