22 "ALBATEOSS" EASTEKN TROPICAL PACIFIC EXPEDITION 



perature is 07 . It becomes 70' at Station 4658, 75°. 3 at Station 4711, and 

 79' at Station 4540*, about 2400 miles nortbwest of Callao, the tempera- 

 ture of the body of water between the surface and 500 fathoms gradually 

 rising from 59'.'} to 67.6 at 50 fathoms, from 54°.l to 65 .3 at 100 fathoms, 

 from 48°.9 to 52''.9 at 200 fathoms, from 44 .6 to 46.7 at 300 fathoms, and 

 from 42 to 44°.l at 400 fathoms. At 600 fathoms the temperature of the 

 same stations differs only 0°.2. It is 39°.4 at the eastern and western stations. 



Taking the sections running in a general way from the north to the 

 south, the line from Callao to Easter Island and that from Aguja Point 

 in a southwesterly direction have been described. On the line from the 

 Galapagos to Easter Island (PI. 4, fig. i) the surface temperature varies from 

 74° to 75° as far south as Station 4705, where the surface temperature 

 becomes 72°. This remains the surface temperature as far south as Station 

 4703, where it is 73°, it rises to 74°.7 at Station 4701, gradually rising to 

 75° towards Easter Island, where it drops to 72°. At Station 4707 we have 

 a warmer body of water between 300 fathoms and the surface than at the 

 stations to the south and north of it. The Humboldt current probably 

 extends as far as the 12° of southern latitude. On the line from the 

 Galapagos to Manga Reva (PI. 5), the surface temperature rises and falls 

 from 76' at 'the Galapagos to 75° at Station 4722 ; from that point, going 

 south and west, it rises gradually to 81°. 5 at Station 4736, and again drops 

 to 80' at Station 4524* and to 77' at Manga Reva ; thus passing acro.ss 

 the colder water of the Humboldt current, which, south of the Galapagos, 

 must be about 800 miles wide, to warmer waters. South towards Manga 

 Reva, at 400 fathoms, the temperature is colder near Manga Reva (41°.7) 

 than near the Galapagos (44°. 1) ; the same is the case at 300 fathoms. But 

 at 200 fathoms the temperature of that depth, while falling from 52°.9, at 

 Station 4718, to 50 .3 at Station 4721, and to 48'. 5 at Station 4724, rises 

 again south, of it, at Station 4728, to 50°.l, and continues to rise to 5r.9, 

 55°.4 and 56°.7 as we go south and west at Stations 4732, 4736, 4739, to 

 drop again to 53'.5 at Manga Reva, at 225 fathoms. 



A similar condition of temperature exists at the 200-fathom line. At 

 100 fathoms the temperature is higher near the Galapagos, at Station 

 4714; it falls from 65°.3 to 55°.7 at Station 4721, to rise to 64°.5 at 

 Station 4724, and gradually rises to 67°.6 at Station 4729, to 70°.5 at 

 Station 4732, to 7r.7 at Station 4736, and to fall to 68°.5 at Station 4739 

 near Manga Reva. 



