the Island of Tristan da Ctinha, ^c. 493 



magnitude in the whole island, is one which gushes out at the 

 base of the mountain immediately behind the cantonment. Ex- 

 cepting this brook, you meet with nothing from one end of the 

 plain to the other but the dry beds of mountain torrents, impe- 

 tuous, indeed, while they flow, but ceasing with the shower to 

 which they owe their existence. 



This singular deficiency of springs may, perhaps, be attributed 

 to the nature of the rocky mass of which the island is formed. 

 Though regularly stratified, the rock is cracked and split in all 

 directions, and the rain transmitted through the spongy, absorbent 

 soil, penetrates easily through its fissures, and sinks doAvn at once 

 to the level of the sea, where it may be seen along the shore gush- 

 ing out through the sand on the reflux of every tide. 



Notwithstanding the frequency of the rains, the climate appears 

 to be abundantly healthy. Not a symptom of sickness appeared 

 among the soldiers during the four months I remained on the 

 island. 



The spot pitched upon for the cantonment is at the northern 

 extremity of the plain, about half a mile from the landing-place, 

 and within range of cannon-shot from the anchorage. It is plen- 

 tifully supplied with excellent water from the stream already men- 

 tioned, which runs close by it, and which, even during the hottest 

 days of summer, maintains the low temperature of 50 degrees. 

 This stream, after running its course for about half a mile, preci- 

 pitates itself in a cascade over the face of the rock into a small 

 sandy cove, where boats can easily put in to supply shipping with 

 Avood and water. 



The prevailing winds off Tristan da Cunha blow from the west- 

 ward and southward. Strong gales are frequent, but rarely con- 

 tinue above twenty-four hours. They never blow quite home on 

 the island, but incline upwards at some distance from the shore, 



3 s 2 and 



