TEMPERATURES. 291 
* Challenger" records 35.1°. These observations show, as we 
approach the coast, an increase of temperature to a depth of 
about 400 fathoms, and a diminution of temperature to a depth 
of about 1,700 fathoms. 
In the section from Sombrero to Virgin Gorda (Fig. 144) 
across the Anegada Channel, the temperatures agree more closely 
with those of the Atlantic sections taken by the “ Challenger ” 
than with the more littoral one taken by the “Blake.” There 
is a marked increase of temperature in the layers between 
100 and 300 fathoms. Between 400 and 600 fathoms, how- 
ever, the water is somewhat colder, and at the bottom the tem- 
> March, 30 L829 
Sombrero T. March ips ABI 
Fig. 144, 
perature is nearly that of the corresponding 
depth three hundred miles at sea. The bot- 
tom temperature of this channel does not in- 
dicate that the cold water is thrown up along ag £858. fun, 
the gentler slope of the channel, as in the temperature sections 
across the Yucatan Channel (Fig. edt and across the narrow 
part of the Straits of Florida. (Fig. 158.) The bottom temper- 
ature, 38° and 383°, indicates that the basin and this channel are 
an oceanic tongue of the Atlantic, and that there must be a ridge, 
extending between Santa Cruz and Porto Rico, which separates 
it from the Caribbean basin.’ Far inside of the Caribbean Sea, 
1 The temperature of 383? also shows mander Brownson sinks to 36° in its deep- 
that the Anegada Channel is divided by est parts. Since this was written, the 
а ridge from the deeper part of the oce- U. S. Fish Commission steamer “ Alba- 
anie basin of the western Atlantie to tross," Lieutenant-Commander Tanner, 
the north of the West Indies, as in that 
basin the temperature observed by the 
* Challenger" and by Lieutenant-Com- 
has developed a ridge running between 
Santa Cruz and Porto Rico, with a great- 
est depth of about 900 fathoms and a 
