28 "ALBATROSS"' TROPICAL PACIFIC EXPEDITION. 



lying islands of Tatakoto and Fakaina run in the same direction as Amanu 

 off Hao, Nukutavake has the same northeasterly trend, as well as Marutea 

 north of the Manga Reva group, while the atolls of Hereheretue, Anu- 

 AniuHinga, and Anu-Anuraro are on a line parallel to the principal trend of 

 the Paumotus from southeast to northwest. The soundings show Herehe- 

 retue to be an independent peak isolated from the Duke of Gloucester 

 group, which may be said to rise from a connecting ridge of nearly 1900 

 fathoms surrounded by depths of more than 2500 fathoms. 



We made more than one hundred and fifty soundings through the Paumotus 

 and their approaches. These have shown in a general way that the western 

 islands are probably all on a great plateau connected perhaps by the 800- 

 fathom line ; that such islands as Anaa may be on spurs or independent 

 smaller plateaux, separated from the main plateau by somewhat deeper water; 

 the same may be the condition of Raroia and Takume, and of Hao and Amanu, 

 while such smaller and isolated islands as Tikei, Aki-Aki, Nukutavake and 

 Pinaki, as well as the Gloucester Lslands, rise from greater depths and are 

 isolated peaks. At any rate, these soundings indicate, as do the soundings 

 off the Fijis, that atolls do not necessarily rise from very great depths, and 

 that in this characteristic atoll district, atolls are found, with steep slopes, it 

 is true, but rising from moderate depths. The slopes of these atolls would 

 probably resemble in every respect the slopes of the elevated coralliferous 

 limestone islands characteristic of the Lau group in Fiji, where they have 

 not been obliterated by erosion, denudation, and atmospheric agencies. 



The deepest sounding among the Paumotus was on the line to the north- 

 ward of Hereheretue in the direction of Mehetia, where we found a depth 

 of 2524 fathoms, and a continuation of the red clay characterizing the 

 soundings since we left Pinaki. In nearly all the soundings among the 

 Paumotus, even at moderate depths not far from the atolls, we brought up 

 manganese particles or small manganese nodules. The last haul, made in 

 deep water on the way from Hereheretue to Mehetia in 2440 fathoms, brought 

 at least half a ton of manganese nodules, the bottom being red clay. 



We steamed about 2500 miles among the Paumotus, and although we 

 had not the advantage of the accurate surveys of the English Hydrographic 

 charts, which made the exploration of Fiji so easy, yet from the structure of 



