204 J. D. Dana on an Isothermal Oceanic Chart, 



Isocryme of 5G F. — At Monterey, on January 1 to 5, the 

 sea-temperature, according to Beechey, was 56° ; but the 

 mean temperature of the sea 'for November 1 to 17 was 

 .")4"91°. In the Yellow Sea the January temperature is 50° 

 to 56° F., and the line of 56° begins south of Chusan. 



Isocryme of 50° F. — At San Francisco, from November 

 18 to December 5, 1826, Beechey found the mean sea-tem- 

 perature to be 51'14° F., and off Monterey, in longitude 123° 

 west, the temperature was 50*75° F., on December 6. But 

 in December of 1826, the mean sea-temperature at San 

 Francisco was 54*78° F. ; and for November, 60-16° F. The 

 line of 50° F, (mean of the coldest thirty consecutive days), 

 probably leaves the coast at Cape Mendocino. 



Isocrymes of 44° and 35° F. — Captain Wilkes found the 

 temperature off the mouth of the Columbia River, through 

 ten degrees of longitude, 48° to 49° F,, during the last of 

 April 1841. The isocrymes of 44° would probably reach the 

 coast not far north of this place. The temperature on Oc- 

 tober 21, in the same latitude, but farther west, 147° west, 

 was 52-08° F. On October 16, in 50° north, 169° west, the 

 temperature was 44*91° F. According to some oceanic tem- 

 peratures for the North Pacific, obtained from Lieutenant 

 Maury, the sea-temperature off northern Niphon, in 41° 

 north, and 142^° east, was 44° F., in March, shewing the in- 

 fluence of the cold Polar current ; and in 42° north, and 

 149*° east, it was 43° F. The line of 44° hence bends south- 

 ward as far as latitude 40° north, on the Japan coast. 



Again in March, in 43° 50' north, 151° east, the sea-tem- 

 perature was 41° F, ; in 44° 50' north, 152° 10' east, 39° F, ; 

 in 46° 20' north, 156° east, 33° F. ; in 49° north, 157" east, 

 33° F. ; and at the same time, west of Kamtschatka, in 55° 

 north, 153° east, 38° F. ; in 55° 50' north, 153° west, 38° F. 

 The line of 35° consequently makes a deep bend, nearly to 

 45° north, along the Kurile Islands. 



South Pacific— Isocrymes of 74°, 68°, and 62° F.— The 

 temperature of the sea at Guayaquil, on August 3, was 

 found by Vaillant to be, in the river, from 70£° to 73£° F., 

 and at the Puna anchorage, August 5 to 12, 74*7° to 75*2° F, 

 But off the coast, August 15, in 2° 22 south, 81° 42' west, 



