THE VOYAGE OF THE BEAGLE 429 



and frequently they purchase whale-boats and horses at the 

 rate of from 50 to 100 dollars. 



After breakfast I went on shore,' and ascended the nearest 

 slope to a height of between two and three thousand feet. 

 The outer mountains are smoQth and conical, but steep ; and 

 the old volcanic rocks, of which they are formed, have been 

 cut through by many profound ravines, diverging from the 

 central broken parts of the island to the coast. Having 

 crossed the narrow low girt of inhabited and fertile land, 

 I followed a smooth steep ridge between two of the deep 

 favines. The vegetation was singular, consisting almost 

 exclusively of small dwarf ferns, mingled higher up, with 

 coarse grass; it was not very dissimilar from that on some 

 of the Welsh hills, and this so close above the orchard of 

 tropical plants on the coast was very surprising. At the 

 highest point, which I reached, trees again appeared. Of 

 the three zones of comparative luxuriance, the lower one 

 owes its moisture, and therefore fertility, to its flatness ; for, 

 being scarcely raised above the level of the sea, the water 

 from the higher land drains away slowly. The intermediate 

 zone does not, like the upper one, reach into a damp and 

 cloudy atmosphere, and therefore remains sterile. The 

 woods in the upper zone are very pretty, tree-ferns replacing 

 the cocoa-nuts on the coast. It must not, however, be 

 supposed that these woods at all equal in splendour the 

 forests of Brazil. The vast numbers of productions, which 

 characterize a continent, cannot be expected to occur in 

 an island. 



From the highest point which I attained, there was a good 

 view of the distant island of Eimeo, dependent on the same 

 sovereign with Tahiti. On the lofty and broken pinnacles, 

 white massive clouds were piled up, which formed an island 

 in the blue sky, as Eimeo itself did in the blue ocean. The 

 island, with the exception of one small gateway, is completely 

 encircled by a reef. At this distance, a narrow but well- 

 defined brilliantly white line was alone visible, where the 

 waves first encountered the wall of coral. The mountains 

 rose abruptly out of the glassy expanse of the lagoon, in- 

 cluded within this narrow white line, outside which the heav- 

 ing waters of the ocean were dark-coloured. The view was 



