138 OBSERVATIONS ON THE WINDS 



Trade, but on the Eastern side it has given way 4°. The N.E. Trade is 

 still much more gusty in Square 40 than in 39, and the gusts are some- 

 times heavy with clear weather. Gusts and puffs are also common in the 

 Northern part of Square 4. 



The S.E. Trade prevails to the Equator on the Western side, and a 

 Southerly wind to 8° N. on the Eastern side of the district ; besides gain- 

 ing so much on the N.E., the S.E. Trade has decidedly increased in force 

 since April. 



June. — The direction of the N.E. Trade continues very similar to what 

 it was in May, drawing into a North- Westerly wind near the coast of 

 Africa. Its force has decidedly increased between 16° and 20° N., but 

 decreased to the Southward of 16° N. It has generally receded 2°, and 

 in some parts of the district 4° to the North. It is still much more gusty 

 and puffy in Square 40 than in Square 39. 



The S.E. Trade prevails to 6° N. except on the extreme Western side 

 of the district ; on its Eastern side South-Westerly winds prevail to 8° N., 

 and even to 10° N. between 15° and 20° W. The S.E. Trade has very 

 decidedly increased in strength since May. 



July. — The N.E. Trade still draws more Northerly and eventually North- 

 westerly as it approaches Africa ; its force has very decidedly decreased 

 since June, and it has receded nearly 4° before the Southerly wind. In 

 Square 40 it is very much more gusty than in Square 39, so much so that 

 although Square 39 had nearly four times as many wind observations as 

 Square 40, the number of gusts and puffs there is not nearly so great. 



The S.E. Trade now prevails to 10° N., and there is a prevailing S.S.W. 

 wind up to 12° N. on the Eastern side of the district ; between 12^ and 14° N. 

 on the same side the prevailing wind is West, and to the Northward of 

 that latitude North-Westerly. Having frequently passed from the North- 

 ward between the Cape Verde Islands and Africa in July, I can well re- 

 member the wind going from N.W. to West and S.W. as we sailed to the 

 Southward. The July diagram gives a picture of the winds then sailed 

 through. The S.E. Trade has increased in force since June, especially the 

 Southerly winds to the North of the Equator. 



Atigust. — The N.E. Trade is still lighter, more Northerly, and in some 

 cases North-Westerly near Africa. Its force has decreased since July, 

 and it has receded about 2° to the Northward, its Southern limit being 

 now in about 12° N., its most Northern verge for the year. 



The S.E. Trade prevails to 6° N. on the Western side of the district, 

 while the prevailing Southerly wind now extends to 14° N. on the Eastern 

 side. On the Northern side of the Equator its force has very decidedly 

 increased since July, but it has not changed much in the South. The 

 S.E. Trade is more Southerly in Square 303 (near South America) as 

 well as more squally and unsteady than in the Squares to the Eastward. 



The diagram shows that between 14° and 8° N., North-Easterly and 

 South-Westerly winds prevail in spaces which lie abreast of each other 

 and in the same latitude, the N.E. being to the Westward of the S.W. ; 

 such a state of the atmosphere makes it probable that whirls revolving 

 similarly to West India Hurricanes will be formed, and suggests that this 

 is their birth place, which has been proved true in some cases. 



