180 VOYAGE TO THE 



chap, others, by directing them to a port in which ships 

 ww may be refitted or repaired, and where they may 

 1826. procure a supply of good water, than which nothing 

 is more important to the navigation of these seas ; 

 as that indispensable article is not found to exist in 

 a pure state anywhere between Otaheite and the 

 coast of Chili, a distance of 4000 miles, Pitcairn 

 Island excepted, where the difficulty of getting it 

 off has already been mentioned. It is also pre- 

 sumed, that the position of the islands having been 

 ascertained, the peaks of Mount Duff, which are 

 high and distinguishable at a great distance, will 

 serve as a guide to the labyrinth of coral islands 

 which the navigator, after passing this groupe, has 

 to thread on his way to the westward. 



This groupe was discovered by the ship Duff, on 

 a missionary voyage, in 1797, and named by Mr. 

 Wilson, her commander, after Admiral Lord Gam- 

 bier. It consists of five large islands and several 

 small ones, all situated in a lagoon formed by a reef 

 of coral. The largest is about six miles in length, 

 and rises into two peaks, elevated 1248 feet above 

 the level of the sea. These peaks, which were called 

 after the Duff, are in the form of wedges, very con- 

 spicuous at a distance, and may be seen fourteen 

 or fifteen leagues. All the islands are steep and 

 rugged, particularly Marsh Island, which at a dis- 

 tance resembles a ship. The external form of these 

 islands at once conveys an impression of their volca- 

 nic origin ; and, on examination, they all appeared 

 to have been subjected to the action of great heat. 



" The general basis of the rocks is a porous 

 basaltic lava, in one place passing into a tuffacious 

 slate ; in another, into the solid and angular column 



