On the Surface Temperature of North Sea and North Atlantic. 15 



is not the place to attempt a further discussion of the cause or origin 

 of the ocean currents. The subject is of great complexity, and there 

 are many points on which liydrographers are not yet agreed. Let us 

 simply try to set forth, in a few words, the outline of the North 

 Atlantic current-system, so far as it is necessary to bear it in mind 

 in our consideration of the temperature phenomena (Fig. 1b). 



• On either side of the Equator there runs, in a westerly direction, 

 a great equatorial current, which is, in the main, due to the steady, 

 long-continued influence of the trade-winds. Guided by the northern 

 coast of the South American continent, from Cape St. Koque north- 



FiG. 1b. — Current-chart of the North Atlantic. 



ward, a great part of this current, from both sides of the Equator, 

 is carried into the Caribbean Sea and the Gulf of Mexico ; while 

 a comparatively small part, splitting off at Cape St. Koque, is 

 deflected southward along the coast of Brazil. The water so heaped 

 up in the West Indian seas must find its outlet ; for, in any body of 

 water, however small or large, you cannot disturb or alter the level 

 of any part without affecting the whole. Partly, then, through a 

 storage of energy produced by the heaping up of this body of water, 

 partly through its own lightness caused by the intense heating to 

 which it has been subject in the landlocked West Indian seas, a great 

 current issues round Cape Sable, and skirts the coast of Florida and 



