300 Mr. Redfield on the 
In view of an attempt to penetrate the Antarctic regions, it 
seems important to ascertain those routes by which the warmer 
currents of the great Southern ocean enter the polar basin, and 
on what routes or meridians they again emerge as ice-bearing 
currents, moving towards the lower latitudes. ‘The thermometer 
will prove an important auxiliary in determining these localities, 
and the course of the polar currents from the Antarctic basin is 
now partially known, by the course of the icebergs which de- 
scend to the lower latitudes. It is by following the course of the 
warmer currents which enter the polar basin that the nearest ap- 
proach will probably be made to the Antarctic pole; and the 
same system of continuous current might afford the means of 
final escape, should a ship be compelled to winter in the ice of 
that perilous region. 
As regards the great system of currents in the Pacific, we may 
infer from the facts already known, that a current from the Ant- 
arctic region sets to the northward, several degrees west of Cape 
Horn, which unites its waters with those of the more temperate 
latitudes in their flow to the coasts of Chili and Peru, and thence 
towards the equator. If an ice current does not thus unite with 
that of the coast, the latter is mainly supported by the great afflux 
of the extratropical currents from the west, which, in performing 
their constant circuit of revolution, next sweep from the coast of 
Peru towards the equatorial latitudes, where they continue their 
course to the westward, again to leave the intertropical latitudes 
with an elevated temperature, which is in turn conveyed to the 
higher latitudes.* 
‘The numerous archipelagos of lane and the extensive groups 
of coral reefs in the Pacific, serve to intercept the regular westerly 
progress of its warm intertropical currents, and to determine more 
than.one circuit of compensation and revolution in each hemis- 
phere. This class of obstructions partly supplies the place of a 
continent, in defining separate basins of revolution for the cur- 
rents of this vast ocean, and this is particularly the case in the 
South Pacific, where these obstructions are scattered over wide 
areas. Hence, strong currents setting to the eastward have 
* From information which I have gathered, I entertain no doubt of the blend- 
ing of this ice current with the general current towards the equator on the west 
coast of South America; and the very reduced temperature which this current 
carries to the equator, at or near the Gallapagos Islands, is proof of the fact. 
* 
