Mr. J. Croll on the Physical Cause of Ocean-currents. 275 



transferred over into the Temperate zone would be so enormous 

 as to make the Atlantic in the temperate regions much warmer 

 than the Atlantic in the torrid region. The relative quantities, 

 as will be seen by referring to my last paper, are these: 1124 

 parts would represent the amount of heat in the temperate re- 

 gion of the Atlantic, and 570 parts the amount in the torrid 

 region. 



But supposing we now take the mean temperature of the 

 Gulf-stream at 52|° instead of 65°, in other words, that the 

 amount of heat conveyed is but 12| units instead of 25 units, and 

 assuming that the amount conveyed by his general movement is 

 even not more than that conveyed by the Gulf-stream at this re- 

 duced rate, what are still the consequences ? By referring to the 

 data afforded in my last paper (p. 257), it can be easily calculated 

 that 202' 5 parts of heat will be removed from the torrid region 

 and transferred to the temperate region. Consequently the 

 amount of heat possessed by the Atlantic in torrid regions will 

 be 772 parts, and that possessed by the Atlantic in temperate 

 regions will be as much as 940 parts. 



This conclusion alone, I would venture to think, is decisive 

 proof that, even supposing such a motion of the ocean as that 

 for which Dr. Carpenter contends were physically possible, 

 still the amount of heat conveyed by means of his general circu- 

 lation must, as regards the Atlantic, be perfectly trifling in com- 

 parison with that conveyed by means of the Gulf-stream. But 

 this is not all ; it proves also that the quantity of heat conveyed 

 by aerial currents and all other means put together is but trifling 

 compared with that conveyed by the Gulf-stream. 



Dr. Peter mann has, by an entirely different line of argument, 

 shown in the most clear and convincing manner that the abnor- 

 mally high temperature of the north-western shores of Europe 

 and the seas around Spitzbergen is owing entirely to the Gulf- 

 stream, and not to any general circulation such as that advocated 

 by Dr. Carpenter. From a series of no fewer than 100,000 obser- 

 vations of temperature in the North Atlantic and in the Arctic 

 seas, he has been enabled to trace with accuracy on his charts 

 the very footsteps of the heat in its passage from the Gulf of 

 Mexico up to the shores of Spitzbergen*. 



Mr. A. G. Findlay's Objections. 

 At the conclusion of the reading of Dr. Carpenter's paper, 



* Der Golfstrom und Standpunkt der thermometrischen Kenntniss des 

 nord-atlantischen Oceans und Landgebiets im Jahre 1870. A translation 

 of this important memoir of Dr. Petermann's^ along with one or two others 

 which have lately appeared in his Geographische Mittheilungen, would be 

 a boon to English readers. 



T2 



