THE GULF STREAM AND THE PANAMA CANAL. 665 



vary much in quality according to where it is manufactured but it 

 will he found to answer the purpose, although probably Howard's is 

 most to be depended on, the common carbonate being too caustic. It 

 is believed that a large proportion of medical practitioners are still un- 

 aware of the remarkable qualities of tbis easily applied remedy, which 

 recommends itself for obvious reasons. The Practitioner. 



THE GULF STREAM AND THE PANAMA CANAL. 



By JAMES GEIKIE, F. E. S. 



""VTONE of the great " rivers of the ocean " has been so frequently 

 J-N and carefully studied as the Gulf Stream of the North Atlantic. 

 Its course, its depth and breadth, its temperature, etc., have all been 

 laboriously investigated, while its influence on the climate of North- 

 western Europe bas formed a very fruitful subject of discussion. The 

 origin of the stream is well known. The Caribbean Sea and the Gulf 

 of Mexico are full-charged with the heated waters of the great equa- 

 torial current, and it is from tbis broad and deep reservoir that the 

 famous Gulf Stream issues by the Straits of Florida to flow in a north- 

 easterly direction toward the coasts of Europe. At the narrowest 

 place in the straits the stream measures 30 statute miles in breadth 

 and 1,950 feet in deptb, but it gradually widens as it passes north 

 until it spreads out over an enormous area. It has been perfectly well 

 ascertained tbat the superficial stratum of the ocean throughout the 

 whole vast space between the great Bank of Newfoundland and the 

 coasts of France has a higher temperature than the normal of those 

 latitudes, and is flowing persistently in a northerly and northeasterly 

 direction toward the coasts of Greenland, Iceland, and Spitzbergen. 

 It is doubtful whether all this body of heated water has passed through 

 the Straits of Florida, and some physicists have maintained that only 

 a very insignificant portion indeed has actually streamed out of the 

 Gulf of Mexico. These writers have, therefore, held that a stoppage 

 of the Gulf Stream would have only an infinitesimal effect upon the 

 general temperature of the North Atlantic and the climate of North- 

 western Europe. This view, however, has been completely overset by 

 Dr. Croll, whose estimate of the enormous heating power of the Gulf 

 Stream is now very generally accepted. According to this eminent 

 physicist and geologist, the total quantity of heat conveyed by that 

 current is probably equal to that of a stream 50 miles broad and 1,000 

 feet deep, flowing at the rate of four miles an hour, and having a mean 

 temperature of not less than 65 a temperature which gradually falls 

 as the current goes north until it is cooled down to at least 40. This 

 estimate gives us 5,578,080,000,000 cubic feet of water per hour, and 



