OCEANIC CIRCULATION. 257 



reason why heat is necessary for Dr. Carpenter s experi 

 ment. Heat is necessary, because the ice must be 

 melted to make the experiment succeed. But comparing 

 the effects of heat and refrigeration (not of heat and 

 the continual inflow of ice-cold water), I conceive that 

 heat would be found altogether the more effective. 



Lastly, as to the wind theory of the Grulf Stream, Dr. 

 Carpenter remarks that, so far as he knows, I am the 

 only man of science in this country agreeing with Capt. 

 Maury in attributing the Grulf Stream to some other 

 cause than the impelling force of the trade winds. He 

 must be aware that there are not half a dozen students 

 of science in this country who have expressed definite 

 opinions on the subject after a thorough and independent 

 inquiry into the evidence. Amongst those who main 

 tain the wind theory there is not one, so far as I know, 

 with whom Dr. Carpenter is in agreement. Mr. Laugh ton 

 disputes the very principle of Dr. Carpenter s reasoning, 

 holding that the change of temperature from equator to 

 poles proceeds too slowly mile for mile to produce the 

 effects which Dr. Carpenter indicates. Mr. Croll, in 

 like manner, has expressed his complete dissent from 

 Dr. Carpenter s reasoning. So also has Mr. Findlay. I 

 believe these gentlemen to be mistaken, and I conceive 

 that I have been able to put my finger on the precise 

 point where their respective lines of reasoning fail. 

 But, if Dr. Carpenter is to take general consent as an 

 argument, and to maintain that I am wrong because he 

 knows of no one who agrees with me, I may as well 

 point out that he is entering into a very questionable 



