EXPLORATIONS, WESTERN ATLANTIC, STEAMER BACHE, 1914. 43 
lines normal to the coast, from Cape Canaveral northward (Agassiz, 
1888, fig. 176), shows that except on the immediate stirface the Gulf 
Stream retains its character as a cool current as far as Cape Fear, 
beyond which it is indistinguishable from the water farther to the 
east. Furthermore, the evidence of salinity is, if anything, even 
more conclusive, because while the bottom water of the channel 
(34.8-34.9°/,,) is continuous with the abyssal water off Habana 
at its west end and hence of the Gulf, off the Bahamas water of this 
salinity was encountered only below 1,800 meters, a vertical drop 
of 1,000 meters from the exit of the channel. Hence, to suppose 
that the bottom water of the Straits enters from the Atlantic abyss, 
we must assume a vertical upwelling of 1,000 meters, of which there 
is no evidence whatever. And it can not be coastal water from the 
north, because far too salt. In short, it is clear that the bottom 
Stations 
10 22 ee SaaS 
900 
1000 
Fia. 46.—Profile of density, at temperature in situ and corrected for pressure, across the Straits of Florida, 
Gun Cay to Cape Florida. 
current in the Straits must flow in the same direction as the surface 
current—1i. e., from the Gulf of Mexico—driving the heavy abyssal 
water of the latter (1.03+) up the slope, thus producing the 
density gradient mentioned above. This bottom current must be 
constant, or nearly so, since the rise of cold comparatively fresh 
water from the deeps of the Gulf up the rising floor of the Straits to 
near the surface at its exit is now shown to be a permanent phe- 
nomenon. In short, the countercurrents occasionally detected by 
Pillsbury on the bottom on the Florida side of the channel at about 
100 fathoms, like the surface countercurrents so long recognized by 
mariners, are merely local reaction phenomena, or eddies. How- 
ever, the velocity of the bottom current is certainly only a fraction 
of the surface drift; and it may be very small indeed. 
The close agreement between the salinity of the bottom of the 
Straits and that of the water in the Atlantic abyss is not the least 
