ST. HELENA 



HISTORICAL AND GEOGRAPHICAL 



THIS most solitary island, probably an extinct tertiary 

 volcano, is one of the peaks of a range of mountains 

 traversing the South Atlantic Ocean, Ascension, with Green 

 Mountain, and Tristan d'Acunha, with peak 8,000 feet high, 

 being parts of the same range. 



Geologists have been unable to fix with exactness its 

 chronological position, from the circumstance of its fossils 

 being peculiar to the island, and therefore furnishing no 

 clue to the geological age of the formations in which they 

 occur. The volcanic forces which have produced the com- 

 plicated disturbances so conspicuous throughout the island 

 must have ceased at a very remote period, as it has evidently 

 retained for ages its existing conformation. At the height 

 of many hundred feet above the level of the sea, shells 

 in considerable numbers are found, embedded in the soil ; 

 these shells were formerly supposed to be of marine origin, 

 but a more careful examination has shown them to be 

 (altogether) of a land species, and of a kind no longer found 

 in a living state. Their destruction, which has been im- 

 puted to the clearing away of the original forests, is more 

 probably owing to geological causes. The principal com- 

 ponent of the island is a dark lava, the successive streams 

 of which are very distinctly marked on the faces of the 

 abrupt cliffs which form the coast. 



In its central and higher parts, a different series of rocks 

 has, from extreme decomposition, produced a clayey soil, 

 which, where not covered with vegetation, is seen in bright 

 bands of colour. Some of this mud or clay presents a 

 wonderful appearance, the tints being of all shades. On 

 one side is seen the beautiful mauve and violet peculiar to 

 the pansy, on another the shaded reds and pinks of ger- 

 aniums, and, at a distance, the colourings appear suitable 

 for pigments, but on inspection are found to be of a very 

 coarse nature. 



