[ ley ] 



XXII. Extract of a Memoir on the Temperature oftho JVater 

 of the Sea, hnth at the Surface and at different Depths, 

 along the Shores and at a Distance from the Coast. By 

 M. F. PKRO^f, Naturalist on the French Expedition to 

 Neiv Holland^. 



vJf ali the cxpt-rinients in nntural philosophy," says 

 M. Peroii, " there are tew the rcsuhs of which are more 

 iciteresling and more curious than those whicli form the 

 suhjt:ct of tills memoir. The meteorologust must derive from 

 ihem v.duahie data in regard to atmosplieric ohservatlons 

 sa the middle of the ocean : they may furnish to the natu- 

 ralist knowledge indispensably necessary in regard to the 

 habitation of the diflVrcnt tribes of marine animals ; and 

 the geologue and philosopher will find in them the most 

 certain facts in regard to the propagation of heat in the 

 middle of the seas, and of the physical state of the interior 

 parts of the globe, the deepest excavations of which can 

 scarcely go beyond the surface. In a word, there is no 

 science which may not derive benefit from the results of 

 experiments of this kind. How much then ought we to 

 be surprised that they have hitherto excited so lutle atten- 

 tion !" 



Frocccding then to an account of the observations which 

 may be made at the surface of the sea, aiul which he him- 

 self pursued from lat. 4^" north to lat. 44*^ south, repeating 

 tliem h)ur times a day, — at six in the morniug, at noon, at 

 six in the evening, and at midnight, — M. Peron deduces 

 from them the following results : — '« The temperature of 

 tlie surface of the sea, cf)lder at noon than the atmosphere, 

 mid warmer at midnight, is nearly in equilibrium with that 

 oi- the morning and evenuig, in such a manlier, however, 

 that the mean term of a given number of observations is 

 more considerable for the water of the sea." 



By a very hajipy applicatifjn of these first results M. Peron 

 easily proves, that tlie supposed heating of the waves is a 

 mistake of sensation produced by the more considerable 

 cooling in a given time of tlie atmosphere than of the 

 waves. The proof he has adduced seems to be as simple 

 as it is incontestable. This prejudice, which is as old as 

 Aristotle, and wliich the incomp'cte experiments of Forster 

 and Irving did not admit of being entirely rejected, not- 

 withstanding the supposition of a principle contrary to 



* Vfom ihc Jouiiiul de Phijsiquf- Riumaiic, an 13. 

 Vol, 21. No. 82. March \S05. I those 



