INFLUENCE OF THE GULF STREAM UPON CLIMATES. 53 



it enters here, "being 3° or 4°, and that in depth 40°* cooler than 

 when it escapes from the Gulf. Taking only this difference in 

 surface temperature as an index of the heat accumulated there, a 

 simple calculation will show that the quantity of heat daily car- 

 ried off by the Gulf Stream from those regions, and discharged 

 over the Atlantic, is sufficient to raise mountains of iron from zero 

 to the melting point, and to keep in flow from them a molten 

 stream of metal greater in volume than the waters daily discharged 

 from the Mississippi River. Who, therefore, can calculate the he- 

 nign influence of this wonderful current upon the climate of the 

 South ? In the pursuit of this subject, the mind is led from na- 

 ture up to the Great Architect of nature ; and what mind will the 

 study of this subject not fill with profitable emotions ? Un- 

 changed and unchanging alone, of all created things, the ocean is 

 the great emblem of its everlasting Creator. " He treadeth upon 

 the waves of the sea," and is seen in the wonders of the deep. 

 Yea, " He calleth for its waters, and poureth them out upon the 

 face of the earth." 



67. In obedience to this call, the aqueous portion of our planet 

 preserves its beautiful system of circulation. By it heat and 

 warmth are dispensed to the extra-tropical regions ; clouds and 

 rain are sent to refresh the dry land ; and by it cooling streams 

 are brought from Polar Seas to temper the heat of the torrid zone. 

 At the depth of two hundred and forty fathoms, the temperature 

 of the currents setting into the Caribbean Sea has been found as 

 low as 48°, while that of the surface was 85°. Another cast with 

 three hundred and eighty-six fathoms gave 43° below against 83° 

 at the surface. The hurricanes of those regions agitate the sea to 

 great depths ; that of 1780 tore rocks up from the bottom seven 

 fathoms deep, and cast them ashore. They therefore can not fail 

 to bring to the surface portions of the cooler water below. 



68. At the very bottom of the Gulf Stream, when its surface 

 temperature was 80°, the deep-sea thermometer of the Coast Sur- 

 vey has recorded a temperature as low as 35° Fahrenheit. 



* Temperature of the Caribbean Sea (from the journals of Mr. Dunsterville) : 

 Surface temperature : 83°, September ; 84°, July ; 83°-83i°, Mosquito Coast. 

 Temperature in depth: 48°, 240 fathoms; 43°, 386 fathoms; 42°, 450 fathoms; 

 43°, 500 fathoms. 



