January 19, 1900.] 



SCIENCE. 



93 



on the east side, which, on our first trip, 

 we passed late in the afternoon. We crossed 

 the island from west to east, the path lead- 

 ing down from the summit of the cliffs 

 bordering the island into a sink at least 40 

 to 50 feet lower than the rim of either face 

 of the island. The sink occupies a little 

 more than one-third the length of the is- 

 land. It is deeper at its southern extremity, 

 where it is said to be 75 to 100 feet below 

 the rim of the adjoining cliffs. 



It is difficult to determine if this sink is 

 the remnant of the former lagoon of the 

 island, or of a sound formed during its ele- 

 vation ; or if it has been formed by the 

 action of rain and atmospheric agencies. 

 The amount of denudation and erosion to 

 which this island has been subjected is 

 very great, as is clearly indicated by the 

 small caiions, pinnacles, and walls of lime- 

 stone, as well as by the crevasses which oc- 

 cur in the surface of the basin in all direc- 

 tions. The extent to which this action has 

 penetrated into the mass of the island is 

 also plainly shown by the great number of 

 caverns which crop out at all levels along 

 the sea face of the cliffs, some of which are 

 of great height, and extend as long galleries 

 into the interior of the island. It is, of 

 course, difiScult, in the face of this extensive 

 denudation and erosion, to state positively 

 what may be part of the ancient lagoon, or 

 sound, and what has been carried away by 

 atmospheric and other agencies since the 

 elevation of the island. At the south end 

 of the island, which is lower than the 

 northern part, there are only two distinct 

 terraces, while at the northern end four 

 terraces can be traced. The southern ex- 

 tremity, however, is still higher than the 

 deepest part of the central sink of the 

 island. 



From Makatea, we visited Niau, Apataki, 

 Tikei, Fakarava, Anaa, Tahanea, Raroia, 

 Takume, Makemo, Tekokota, Hikueru, 

 Marokau, Hao, Aki-Aki, Nukutavake, 



going as far east as Pinaki, when we turned 

 westward again to Nukutipipi. 



On arriving at Pinaki we decided to give 

 up the exploration of the eastern extremity 

 of the Paumotus, and not to make our con- 

 templated visit to the Gambler Islands, 

 our time having been greatly curtailed by 

 delays at Fakarava and Makemo, from bad 

 weather and the non-arrival of our coal 

 supply. We therefore reluctantly turned 

 westward again and made for the Gloucester 

 Islands. These, as well as Hereheretue, 

 proved most interesting ; they formed, as it 

 were, an epitome of what we had seen on a 

 gigantic scale in the larger atolls of the 

 western and central Paumotus. We could 

 see at a glance in such small atolls as Nuk- 

 utipipi and Anu-Anurunga, the connection 

 between structural features which, in an 

 atoll 40 miles in length and from 10 to 15 

 miles in width, it was often difficult to de- 

 termine. 



Except at ISTukutavake we found no vil- 

 lage in which the habits of the natives had 

 not been more or less modified by civiliza- 

 tion. The Paumotu Islanders have prac- 

 tically given up building their own houses ; 

 they use European models and their roofs 

 are composed in great part of galvanized 

 iron. There are also but few of the orig- 

 inal native canoes to be seen. In a few 

 years all traces of their customs and crafts 

 will have disappeared. 



We also steamed by Kauehi, Tsenga and 

 Tuanaka. We anchored in Fakarava and 

 Makemo lagoons, spending a number of 

 days in both these atolls. We usually 

 timed our visits to the islands where we 

 could not anchor so as to spend the day, or 

 the greater part of the day, at these atolls, 

 making our passages at night, and sound- 

 ing whenever practicable on the way. 



After leaving Tahiti we made over 100 

 soundings. These have shown in a general 

 way that the western islands are probably 

 all on a great plateau connected perhaps by 



