426 OBSERVATIONS ON THE GUERENTS. 



much light on this remarkable and interesting stream, which he contends 

 is the extension of the true Gulf Stream, we quote his words as to its in- 

 fluence on N.W. Europe, &c. (" Mittheilungen," 1870, page 220, &c.). 



" While the (Gulf) Stream has in January, on the 50th parallel of lati- 

 tude, still a temperature of 54-5°, the thermometer shows at the same time, 

 at Prague or at Ratibor (in Silesia), on the same parallel of latitude, tem- 

 peratures of —24°, and still lower ones. (As before remarked, there can 

 be no comparison between land and ocean temperatures. The immense 

 differences of radiation and evaporation, or deposition, between the two 

 conditions, render them quite incongruous. There is no better evidence of 

 this than in the climate about the North Cape. While the sea around it in 

 January has a temperature of 36°, that of the land is sometimes — 24° 

 and —26° below zero, a difference of more than 60° of temperature, and 

 this is clearly owing to the direction of the wind, which, as Mr. Buchan 

 shows, prevails from the S.S.E.*). The isothermal hne of 54-5° (10° R.) 

 runs up in July toward Iceland and the Faeroe Islands to the 61st degree 

 of latitude. There it meets, for the second time, the Polar Stream, which 

 on the East coast of Iceland again threatens to block up its way and to 

 destroy it. 



"The summer observations of temperature collected by Admiral Irminger, 

 of the Danish Royal Navy, have thrown great light on the important ques- 

 tion of this warm-water extension. His conclusions are based on the ob- 

 servations he zealously collected from the voyages of the Danish vessels 

 navigating in the summer season between Denmark, the Orkneys, and 

 Greenland. f 



" As already noticed, an arm of the Gulf Stream proceeds towards the 

 North along the West coast of Iceland, and this arm extends to the East 

 along the entire North coast, and does not meet the Polar Stream until it 

 has reached the N.E. end of the island. Only for the months of May, June, 

 July, and August, figures are found in Irminger's collection off the North 

 coast of Iceland, all of which show a higher temperature than those off the 

 East coast. In July, temperatures were observed on the North coast, of 

 45-0°, 47-1°, and 49-3° (Lord Dufferin, 46-0°), while off the East coast, for 

 6° of longitude, none higher than from 40° to 42-6° were found. 



• There could be no better evidence of the fallacy of comparing a land climate with 

 that influenced by the sea surface than this above quoted. The direction of this S.S.E. 

 wind, passing over some of the coldest plains in Europe, and probably also from great 

 distances, has thus lowered its temperature to this extreme degree. A S.W. wind, on 

 the contrary, brings, as may be readily inferred, the warmer influences of the surface 

 it passes over. Therefore the ocean temperature, on the Western side of the Atlantic, 

 has no manner of relation to the temperature of places many hundreds of miles inland, 

 on its Eastern side, although in the same latitude. 



t Dr. George Forchhammer, Professor at the Copenhagen University, gave a very 

 valuable paper "On the Composition of Sea-water iu different parts of the Ocean," 

 which appears in the " Philosophical Transactions of the Royal Society," 1865, page 

 203, et seq. By his extended researches, he has shown the origin of various branches 

 of the Ooean circulation. As regards that flowing around Cape Farewell from the East- 

 ward, he says, from its great salinity, 35-278 per 1,000, that it is very probably the re- 

 turning Gulf Stream. At all events, it is no polar current, which will be easily seen on 

 comparing it with the Baffin's Bay current, with a salinity of 33'281, or with the water 

 North of Spitzbergen, 33623. 



