9 
Warm Area. 
Cold Area. 
DEGR. PAH. 
DEGR. FAH. 
SURFACE. 
52 
SURFACE. 
52 
51 
51 
fin 
fin 
4Q 
4Q 
1 UU iawioms 
48 
iuu iaunoms 
onn An 
£i\j\) U.U. 
4-7 
47 
oUU QO. 
Aft 
w\) ao. 
4*» 
to 
^flrt Art 
44 
44 
ouu ao. 
4^1 
200 do. 
*tt> 
7UU GO. 
AO 
'icii 
1 ou ao. 
ill 
rkl 
39 
38 
37 
36 
35 
300 do. 
34 
33 
400 do. 
32 
500 do. 
31 
600 do. 
30 
650 do. 
29 5 
A glance at the Tables will show that the inferences drawn in 1868 from 
the few temperature soundings taken by the Lightning, as to the co-existence 
of two entirely different submarine climates in the region above alluded to, 
were substantially correct. It will be seen that in the ' ' warm area' ' the rate of 
descent in temperature bears nearly the same proportion to the vertical depth 
as it does in the North Atlantic basin ; there is the same rapid fall in the 
first 100 fathoms, after which the fall is slower up to 500 fathoms, and then 
slightly increases after that point. In the * 'coldarea" however, as ascertained 
by the serial soundings of the " Porcupine," a very different state of tilings 
prevails. At a depth of 200 fathoms in the warm area the temperature 
was 47°, in the cold it was 45°7, but while in the warm area there was a 
slow and pretty uniform descent in the next 500 fathoms, amounting only 
to four degrees in the whole, in the cold area the temperature fell fifteen 
degrees in the next 100 fathoms, making the temperature at 300 fathoms 
depth 30° 8, but even this was not the lowest, the temperature at 640 
