THE GULF STREAM. 383 



physical changes which have occurred on the South-Eastern extremity of 

 the North American continent for the cause, or at least a partial cause, of 

 those changes of temperature which have taken place in the beginning 

 of the present period, in those very North-Western portions of Europe 

 which are now so much warmer than the corresponding latitudes on the 

 Eastern side of the American continent ; and which, soon after the 

 accumulation of the glacial drift, had as low a mean annual temperature 

 as the coasts of Labrador, Nova Scotia, and New England in our day. 



The present condition of the Florida country then is this : — On the 

 outer edge we have the " Beef," a submerged line of danger to the 

 navigator, which rises nearly to the surface of the water, on which every 

 variety of coral life is developed. It follows the line of kays within it in 

 a perfectly parallel curve, and forms the boundary to the Ship Channel 

 inside it for hundreds of miles. Upon this line and space are small patches 

 which rise above the surface, of course of dead coral, and upon these is 

 gradually heaped the debris of the reef, in the form of sand and broken 

 coral, till it attains a permanent level above the surface. Within this 

 reef is a channel with depths of 2 to 7 and 8 fathoms, which, with care and 

 some knowledge, may be navigated, and which has various openings to it 

 through the reef. 



These kays consist generally of coral boulders and the fragments of coral 

 and shells heaped up by the action of the waves, and which have become 

 agglutinated by some obscure process, till they become firm land, not by 

 the upheaval of old coral growths, but by the action of a stormy sea and 

 tremendous waves. They are generally level, and it is only at times that 

 the water rises sufficiently to account for their elevation. On a later 

 page is given an instance of an extraordinary rise in the waters. 



In the year 1846, the water rose 8| feet above high-water mark at Kay 

 Vaccas. Kay West was entirely inundated during the same gale ; and 

 though it is somewhat protected by the reef, the rushes, driven upon it by 

 the flood, might be seen among the trees and bushes, at a height almost 

 equal to its loftiest summit. In 1841 the water rose 10 feet above hi^^h- 

 water mark at Cape Romaine, on the Western shore of the peninsula. 



Proceeding still farther Northward, we find an important result of the 

 operation of the Gulf Stream, in the formation of the range of the Sea 

 Islands of Georgia, so famous for the growth of its peculiar cotton. These 

 low alluvial deposits are the results of gradual accretion still going on, 

 and afford a genial soil for the cotton plant, while the tepid water of the 

 Gulf Stream, which rushes past them, tempers the Easterly winds which 

 blow on this seaboard, and add their important influences to the peculiar 

 growth of this cotton plant. 



(369.) Characteristics. — The Indications of the Stream are the appearatice 

 and the temperature of the water. In its lower latitudes and usual course, 

 where it flows uninterrupted, it may be known in fair weather by ite 

 smooth and clear blue surface. Outside the line formed by a ripple on its 

 edge, the water in some places appears like boiUng water of a blue colour ; 

 and, in other places, it foams like the waters of a cataract, even in dead 

 calms, and in deep water. 



On the outer or S.E. edge of the Stream, especially in fair weather, 



