THE PAUMOTUS. 11 



Wilkes looked upon the coral islands of the Paumotiis as showing un- 

 equivocal signs that they are undergoing dissolution.^ He based this opinion 

 on the position and size of some of the coral blocks on the top of the reefs, 

 which he considers — and justly, to my mind — as having formed an upper 

 shelf of which they are the sole remains. He was greatly struck with the 

 varying heights of the islands and coral reefs of the Paumotus. 



I will refer to the more detailed observations of Dana in the descrip- 

 tion of the various islands of the Paumotus. 



Next to the Maldives the Paumotu Archipelago contains the greatest 

 number of known atolls; then come the Marshall and the Fiji Islands. 

 The Paumotus extend for over 1000 miles in a southeast to northwest 

 direction from Manga Reva to Matahiva, and the greatest width of the 

 belt of islands from Anaa to Fakaina is over 300 miles in an easterly direc- 

 tion (Pis. 201, 202). There are in addition a number of detached islands 

 on the eastern flank, of the group which present no feature differing from 

 those of the atolls we visited. The charts of this group are somewhat inac- 

 curate, and, while most useful as sketches, cannot be used as are the admir- 

 able charts of the Fijis, of the great barrier reef of Australia, of the New 

 Hebrides, Solomon, and Tonga groups, or those of the Society, Cook Islands, 

 or Maldives, to determine the points of interest for a first examination of 

 the islands. To obviate this difficulty we steamed around each atoll so as to 

 obtain a general view of it, and when we entered the lagoon we limited our 

 examination to the interesting points we had noticed on skirting the land 

 rim close to the outer reef 



The general sketch charts published by the French Hydrographic 

 Office are far more accurate than those which have been issued either by 

 the British or the American Hydrographic Office. It is true that we have a 

 large number of sketches of various atolls of the Paumotus made by Wilkes 

 in the early forties, as well as surveys by Beechey and Fitzroy and a few 

 sketches by Kotzebue, Bellingshausen, and Duperrey in the beginning of the 

 last century, but they do not compare in accuracy with later or more recent 

 surveys. The islands which have been sketched by Wilkes are Ahe,^ 



1 Loc. cit., p. 2e<>, Vol. IV. 



^ I have adopted the spelling of the French Charts of the Paumotus. Depot des cartes et plans de 

 la marine, 985. 



