320 On an Fuothirmat Oceanic Chart, illustrating 
ward nearer the coast-line, bending far back the western extremity 
of each of the isocrymes. ; 
In the Pacific, the tropical currents show their effects near the 
coasts of New Holland and China, in a gradual divergence of the 
lines from the equator. The ranges of islands forming the Tara- 
wan, Radack, and Ralick Groups, appear to divert the current 
northward in that part of the North Pacific, and consequently the 
isocrymal lines bend northward near longitudes 170° west and 
180°; and near Niphon, that of 68° showsa still greater northern 
flexure. 
The influence of the extra-tropical currents in this ocean is re- 
markably great. The southern flows from the west and south, 
bending upward the line of 56° F. along the South American 
coast, producing at Valparaiso at times a sea-temperature of 48° 
F. Still farther north, it throws the line of 68° F. even beyond 
the equator and the Gallapagos ; and that of 74° F-., nearly fifteen 
hundred miles from the coast, and four hundred north of the 
equator. The line of 62° F. reaches even beyond Payta, the 
sea-temperature at this place being sometimes below 61°. 
The north polar current produces the same result along the 
eastern coast of Asia, as on the eastern of America. The iso- 
cryme of 74° F. is bent southward from the parallel of 23° to 
12° 30’ north; and that of 68° F. from 34° to 15° north, and 
the latter deflection is even longer than the corresponding one in 
e Atlantic. The trend of the coast opens it to the continued 
action of this current until the bend in the outline of Cochin 
By comparing the regions of the different oceans, north and 
south of the equator, we may arrive at the mean position of the 
several isocrymes, and thereby discover on a grander scale, the 
influence of the various oceanic movements. 
For the purpose of reaching mean results, the Middle Pacific 
is the most favorable ocean for study. This is apparent in 1ts 
greater extent, and the wide distance between the modifying con- 
tinents ; and also no less in the greater actual regularity of the 
rymes. 
