668 J A M A I C A. 



will fometimes create a fmall difference; and in rivers which fall into 

 deep bays on the South fide, the flux and reflux rarely exceed one foot. 

 The influence of the before-mentioned bodies upon the Tropical feas, is 

 doubtlefs one caufe of thofe prodigious currents obferved among all thefe 

 iilands fituated within them. Thefe currents are faid to be variable, as 

 well in their times of fetting in, as their direflion; however, a more cer- 

 tain knowledge of their motions and doftrine, which can only be tlie re- 

 fult of very careful and regular obfervation, feems defireable, for the fake 

 of navigation. The currents on the South coafl of Jamaica ufually fet 

 during the reign of the regular trade wind, to the N. W., into the gulph 

 of Mexico, and circulate to the N. through the Florida channel ; while 

 the Norths prevail, they tend rather S. Wefterly. 



The continual torrent which fweeps through the gulph of Florida, and 

 along the North American coaft, with fuch flirength and rapidity, as 

 even to have been remarked fo high as the ifle Sable, in North latitude 

 44" 30', is attributed to a certain permanent caufe; and, if the theory be 

 ripht, can feldom vary much in its direction from the influence of winds, 



O 



or, at leaft, only to fome little depth beneath the furface. 



Carting our eyes over the map of this quarter of the globe, we obferve 

 a great multitude of iflands, rocks, and cayes, which form a femicircular 

 barrier, from the N. W extremity of the Bahamas, adjacent to North 

 America, quite to the ifland of Trinidado, nigh to the Southern part of 

 the continent; ranging through an extent of fifteen degrees of latitude. 

 The paffage of the water from the great Atlantic ocean into the Carrib- 

 bean Tea, and Bay of Mexico, is, therefore, confiderably obftrufted j and 

 being inccfl'antly urged on to the Weflward, and N. W., during great 

 part of the year, by the trade, or S. E. and Eafterly winds, and by the 

 preffiire or gravitation of its own vaft body near the Equator, it ought 

 to caufe ftrong currents in the like direftion between feveral of the wind- 

 ward Antilles, or Carribbee iflands ; in a fimilar manner as the fl:ream of 

 a river, whofj motion is accelerated between the arches of a bridge. This 

 current muft diminifli in violence, when the water finds ample room to 

 expand, and diffufe itfelf freely on every fide, as it does after its arrival 

 in the Carribbcan fea ; but it is again impeded, at its entrance into the 

 Bay of Mexico, by the two Capes of St. Antonio on the S. W, end of 

 Cuba, and Catoche on the oppofite continent ; which projed to meet each 

 other, like two moles or lunettes at the mouth of a fea port ; and, ap- 

 proaching 



