26 "ALBATROSS" EASTERN TROPICAL PACIFIC EXPEDITION, 



tion towards Cape San Francisco. In this area, south of the equator and 

 southwest of the Galapagos, lies a small, isolated, elliptical area, having a 

 temperature of 77', and one of 75' near Easter Island running in a northeast- 

 erly direction. An area of cold water exists between the 65° and 70" curve, 

 extending from 20' of southern latitude to the equator, where the curves meet 

 across the ridge off Cape San Francisco. The coldest water of this area is 

 immediately west of the South American coast. It will be noted that, 

 owing to the mass of cold water between 65° and 70° which is forcing its 

 way north, the belts of temperature are not continuous either in the colder 

 area or in the adjoining somewhat warmer area having a temperature be- 

 tween 70' and 75°. Belts of warm and colder water alternate with one 

 another, forming thus a most singular set of longer or shorter temperature 

 lines running from south to north. It is only outside of the 75° curve line 

 that the temperature lines assume any regularity and limit definite areas. 

 The surface temperature of the Eastern Pacific is nowhere below 77° north 

 of the equator, with the exception of a very narrow strip north of the Gala- 

 pagos, where the temperature falls to 75°. South of the equator, on the con- 

 trary, east of about 110° W. Long, to the South American coast, the surface 

 of this great body of water is nowhere higher than 75°, and gradually 

 becomes colder as we go east, reaching its minimum of 65° immediately off 

 the South American coast. Wliile west of the 75° curve the temperature 

 gradually rises toward the warm area enclosed by the 80° curve, which lies 

 to eastward of the Paumotus. 



The warm areas north and south of the equator are separated by a wide 

 belt in which the surface temperature does not fall below 79°. The warm 

 shore belt (of 80°) is off the Mexican coast, separated from the northern 

 equatorial warm belt of 80° by surface water of 79°, but between the former 

 and the 75° curve, which extends eastward nearly on the line of the equator, 

 the surface temperatures gradually fall from 80° to 75° passing south. 



SPECIFIC GRAVITIES. 



Plate 3''. 

 On Plate 3'^ the specific gravity is indicated merely by the decimal 

 numbers ; to avoid confusion, instead of being given as 1.0252 or 1.0260, it 

 is given only as 252 or 260 etc., etc. . . . ; the 1.0 should be prefixed to each 

 record. The heavy lines on PI. 3-' indicate the specific gravities of 1.0240, 

 1.0245, 1.0250, 1.0255, 1.0260. 



