chap. i. Valleys near the Coast, 25 



centre of the island. Notwithstanding these differences 

 of inclination, their correspondence in external form, 

 and in the composition both of their upper and lower 

 parts, — their relative position in one curved line, with 

 their steepest sides turned inwards, — all seem to show 

 that they originally formed parts of one platform ; 

 which platform, as before remarked, probably extended 

 round a considerable portion of the circumference of 

 the island. The upper strata certainly flowed as lava, 

 and probably beneath the sea, as perhaps did the lower 

 feldspathic masses : how then come these strata to 

 hold their present position, and whence were they 

 erupted ? 



In the centre of the island * there are lofty moun- 

 tains, but they are separated from the steep inland 

 flanks of these hills by a wide space of lower country : 

 the interior mountains, moreover, seem to have been 

 the source of those great streams of basaltic lava which, 

 contracting as they pass between the bases of the hills 

 in question, expand into the coast-plains. Round the 

 shores of St. Helena there is a rudely-formed ring of 

 basaltic rocks, and at Mauritius there are remnants of 

 another such a ring round part, if not round the whole, 

 of the island ; here again the same question immediately 

 occurs, how come these masses to hold their present 

 position, and whence were they erupted ? The same 

 answer, whatever it may be, probably applies in these 

 three cases ; and in a future chapter we shall recur to 

 this subject. 



Valleys near the coast. — These are broad, very flat, 



1 I saw very little of the inland parts of the island. Near the 

 village of St. Domingo, there are magnificent cliffs of rather coarsely 

 crystallised basaltic lava. Following the little stream in this 

 valley, about a mile above the village, the base of the great cliff 

 was formed of a compact fine-grained basalt, conformably covered 

 by a bed of pebbles. Near Fuentes, I met with pap-formed hills of 

 the compact feldspathic series of rocks. 



