THE WINDS. 271 



772. " If a ship which has conic into the belt of cahna, between 

 May and September, can lie still in tlic 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 sec the belt 

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

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

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

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

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

 mains tlierc anchored on the north side."* 



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

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

 of the wind at sea is an immense influence. It is fre(][uently traced 

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

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

 Africa, in the sunnner and autunmal months, is such as to be felt 

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

 allel of 13^ north. Between this parallel and the e{|uator, the 

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

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

 to the C(][uator, they stop and ascend over the desert sands of the 

 continent. The southeast trade-winds, arriving at the e([uator 

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

 their crossing the Ihie, continue their course, and blow hoDic 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 cm- 

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

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

 10*^ or 15^ of the mouth of the Amazon. 



774. Indeed, when wc come to study tlie clTccts of South Amer- 

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

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

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



* Natuurkiindigo Bcschrijving dor zcccii, door M. F. Maury, LTil^-, Luitcnant 

 dcr Nord-Amorikaanscho Marine, vcrtaald door M. II. Jaiiscn, Luitcnant dcr Zoo. 

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



