10 
fathoms being 29° 6. Thus, while the temperatures of the superficial strata 
of the water in the warm and cold areas are nearly the same, the temper- 
ature of the deeper stratum in the cold area, which may have a thickness 
of more than 2000 feet, ranges from the freezing point of fresh water to 
2|° below it. Between the two is a stratum of intermixture of about 100 
fathoms thickness, marking the transition between the warm superficial 
layer and the frigid water beneath. In the North Atlantic basin, as before 
remarked, this stratum of intermixture occupies the space between 500 
and 850 fathoms. 
It seems impossible to account for these phenomena on any other hypo- 
thesis than that of the direct deviation of this frigid water from the Arctic 
basin ; and this agrees very well with the other facts observed in the 
course of the exploration ; viz. the sand covering the bottom contains par- 
ticles of volcanic minerals, probably brought down from Jan Meyen or 
Spitzbergen ; and also the Fauna of the cold area has a decidedly Boreal 
type, especially in the Crustaceans, Echinoderms, Sponges, &c, many of 
the animals which are found in it, having only been hitherto found on the 
shores of Greenland, Iceland, or Spitzbergen. 
It may be a matter of surprise that this cold current, if it comes, as is 
believed, from the Arctic basin, should flow to the west of the Faroes, 
instead of coming by the apparently more direct route between the Faroes 
and Iceland. It must be borne in mind, however, that this current flows 
at a depth of 300 fathoms below the surface, and as, except in a narrow- 
channel at the S.E. corner of Iceland, there is no depth so great as this 
until a point West of the Faroes is reached, an effectual barrier is presented 
to the movement of the frigid water except in the channel in which it is 
actually found to exist. 
The temperatures obtained in the warm area tend to show, in like man- 
ner, that its whole body of water is derived from a southern source. 
Disregarding the fall of temperature in the first 100 fathoms as due chiefly 
to local causes, the temperature of the body of water from 100 fathoms to 
750 fathoms depth is nearly the same in the Bay of Biscay in lat. 49° N. and 
in the warm area in lat. 59°5/ N. In the latter case the lowest temperature 
observed is considerably above the isotherm of its latitude, and this eleva- 
tion could not be maintained against the cooling influence of the Arctic 
stream but for a continual supply of heat from a warmer region . 
A general review of the temperature observations appears to show, 
therefore, that there is a great general movement of Equatorial water 
towards the Polar area going on near the surface of the sea, and that, 
