428 APPENDIX. 



of the temperature, in increasing depths, are, in the 

 South Sea, of the 13th and 14th of September, 

 1817, in 36° north latitude, and 148° west longi- 

 tude. Besides confirming the general law, that 

 the cold increases with the depth, they also afford 

 the following results. 



1. The upper parts of the water show a particu- 

 lar warmth, as the temperature, in the first eight fa- 

 thoms, diminished only 0°,4 R.,but from that depth 

 to twenty-five fathoms, full 6° R. From twenty-five 

 fathoms to a hundred fathoms' depth, the decrease 

 of warmth is considerably less, since, in the next 

 twenty-five fathoms, it is only 1°, 7 R., and in the 

 next fifty fathoms, only 1°, 5 R. ; a decrease, which 

 amounts to only the tenth part of the preceding. 

 It is still slower between a hundred and three hun- 

 dred fathoms. 



2. If we compare these observations with those 

 of the 6th of June, 1816, in 37° north, and in 

 199° west longitude, consequently, in the same 

 parallel of latitude, the influence of the season is 

 particularly observable in the temperature, on the 

 surface, which in June is 13° R., in September 

 18° R. It, however, does not go much deeper than 

 from twenty-five to fifty fathoms ; and at a hun- 

 dred fathoms it is already within the limits of the 

 accuracy of such observations; for we have, 



r 6th June, 9°, 4 R. 



For 100 fathoms J 13th September, 9, 4< — 



i 14th September, 8, 6 — 



