THE WINDS. 271 



772. " If a ship which has come into the belt of calms, between 

 May and September, can lie still in the place where it came into 

 this belt, — cast anchor for example — then it would perceive a turn- 

 ing of the monsoon or of the trade-wind. It would see the belt 

 of calms draw away to the north, and afterward get the southwest 

 monsoon, or, standing more westerly, perhaps the southeast trade. 

 On the contrary, later than September, this ship lying at anchor 

 will see the northeast gradually awake. The belt of calms then 

 moves toward the south, and removes from the ship which re- 

 mains there anchored on the north side."* 



773. The investigations that have taken place at the Observato- 

 ry show that the influence of the land upon the normal directions 

 of the wind at sea is an immense influence. It is frequently traced 

 for a thousand miles or more oiit upon the ocean. For instance, the 

 action of the sun's rays upon the great deserts and arid plains of 

 Africa, in the summer and autumnal months, is such as to be felt 

 nearly across the Atlantic Ocean between the equator and the par- 

 allel of 13° north. Between this parallel and the equator, the 

 northeast trade-winds, during these seasons, are arrested in their 

 course by the heated plains of Africa ; instead of " blowing home" 

 to the equator, they stop and ascend over the desert sands of the 

 continent. The southeast trade-winds, arriving at the equator 

 during this period, and finding no northeast trades there to contest 

 their crossing the line, continue their course, and blow home as a 

 southwest monsoon to the deserts where they ascend. These 

 southwardly monsoons bring the rains which divide the seasons in 

 these parts of the African coast. The region of the ocean em- 

 braced by these monsoons is cuneiform in its shape, having its 

 base resting upon Afiica, and its apex stretching over till within 

 10° or 15° of the mouth of the Amazon. 



774. Indeed, when we come to study the effects of South Amer- 

 ica and Africa (as developed by the Wind and Current Charts) 

 upon the winds at sea, we should be led to the conclusion — had 

 the foot of civilized man never trod the interior of these two con- 



* Natuurkiindige Beschrijving der zeeen, door M. F. Maury, LL.D., Luitenant 

 der Nord-Amerikaansche Marine, vertaald door M. H, Jansen, Luitenant der Zee. 

 (Bijdrage.) Dordrecht, P. K. Braat. 1855. 



