67 



It is very remarkable, that, notwithstanding 

 the immensity of the ocean, and the rapidity of 

 the currents, there is a great uniformity every 

 where in the maximum of heat in the equinoc- 

 tial seas. Mr. Churruca found this maximum, 

 in 1788, in the Atlantic Ocean, at 28*7°; Mr. 

 Perrins, in 1804, at 28*2° ; Mr. Rodman * in 

 his voyage from Philadelphia toBatavia, at 28*8°; 

 and Mr. Quevedo, at 28*6°. In the South Sea I 

 observed it the same year at 29*3°; consequently, 

 the differences scarcely exceed 1° of the centi- 

 grade thermometer, or | 8 of the total heat. We 

 must recollect, that, under the temperate zone, 

 to the north of the parallel of 45°, the mean 

 temperatures of different years vary more than 

 2°, or a fifth of the quantity of caloric that a de- 

 terminate part of the Globe ^ receives. 



* Coxe, Philadelphia!] Medical Museum, vol. i, p. 83. 



t Geneva from 1796 to 1809; 7'87* : 8 34° j 8°; 7'47 0 ; 

 8«38 # ; 8-49°; 8 49°; 827°; 8 5°; 712°; 8-73°; 7*78°; 

 6*68°, and 7*54° of Reaumur's thermometer: Paris, at the 

 Observatory, from 1803 to 1810; ll'95 9 ; 1075*; 10'35»; 

 10'5S # ; 10-50° ; 10-65°; 1110°; and 9 79° of the centi- 

 grade thermometer. In proportion as we approach the tro- 

 pics, the variations of the annual temperature diminish 

 Rome (lat.41° 53') from 1789 to 1792; 13 6° ; 12-5°; 134° ^ 

 and 12*9°, Reaum. (Buch. in Gilbert's Annalen der Physik, t. 

 24, p. 238). Philadelphia, (lat. 39* 56') from 1797 to 1803. 

 12 7o; 11 -6* ; lV8o ; ll'7o; 12-7°; and 12-8° of the centi- 

 grade thermometer. From these very accurate observations 

 it results, that the extremes at Geneva have been 2* 5° ; at 

 Paris 2*2° ; at Rome, 1*3°; and at Philadelphia, 1*1 0 of the 



