196 THE PHYSICAL GEOGRAPHY OF THE SEA. 



the vegetable and animal kingdoms ; and that quantity is depend- 

 ent upon the arrangement and the proportions that we see in na^ 

 ture between the land and the water — between mountain and des- 

 ert, river and sea. If the seas and evaporating surfaces were 

 changed, and removed from the places they occupy to other 

 places, the principal places of precipitation probably would also 

 be changed : whole families of plants would wither and die for 

 want of cloud and sunshine, dry and wet, in proper proportions 

 and in due season ; and, with the blight of plants, whole tribes of 

 animals would also perish. Under such a chance arrangement, 

 man would no longer be able to rely upon the early and the latter 

 rain, or to count with certainty upon the rains being sent in due 

 season for seed-time and harvest. And that the rain will be sent 

 in due season, we are assured from on high ; and when w^e recol- 

 lect who it is that " sendeth" it, we feel the conviction strong 

 within us that He that sendeth the rain has the winds for his 

 messengers ; and that they may do his bidding, the land and the 

 sea were arranged, both as to position and relative proportions, 

 where they are, and as they are. 



408. It should be borne in mind that the southeast trade-winds, 

 after they rise up at the equator (Plate I.), have to overleap the 

 northeast trade-winds. Consequently, they do not touch the earth 

 until near the tropic of Cancer (see the bearded arrows, Plate 

 Vn.) — more frequently to the north than to the south of it ; but 

 for a part of every year, the place where these vaulting southeast 

 trades first strike the earth, after leaving the other hemisphere, is 

 very near this tropic. On the equatorial side of it, be it remem- 

 bered, the northeast trade-winds blow ; on the polar side, what 

 were the southeast trades, and what are now the prevailing south- 

 westerly winds of our hemisphere, prevail. Now examine Plate 

 VIL, and it will be seen that the upper half of the Red Sea is 

 north of the tropic of Cancer ; the lower half is to the south of 

 it ; that the latter is within the northeast trade-wind region ; the 

 former, in the region where the southwest passage winds are the 

 prevailing winds. 



409. The River Tigris is probably evaporated from the upper 

 half of this sea by these winds ; while the northeast trade-winds 

 take up from the lower half those vapors which feed the Nile with 

 rain, and which the clouds deliver to the cold demands of tht> 



