AND PORTO SANTO. 57 



much more symmetrical than those at, and near, the water-side, 

 proving that Dolomieu's opinion, that it is the effect of their 

 sudden coohng in water, is unfounded. It is every where evident, 

 that this structure is accidental, and arises from divisions subse- 

 quent to the formation of the mass. On my way back I found 

 the stum falcarium, growdng to the size of a large shrub. I re- 

 turned to Funchal, by the Pico da Cruz, which affords a fine view 

 of the peaks of the interior, and of the Jardin de Serra, as may be 

 conceived from the accompanying sketch, Plate 4, B. ; it is 3237 

 feet above the sea. I also passed over the peak of Giram, (the 

 highest land seen to the westward of Funchal, on entering the 

 bay,) which I found to be 2185 feet above the sea. 



Going close along shore in a boat, to the westward, and passing 

 the natural section, which I have already described, and which is 

 terminated by a ravine, we lose sight of the tufa, which has either 

 sHpped beneath the sea, or has not been deposited in this direction. 

 The basalt, which appears to be a continuation of that reposing on 

 the tufa on the eastward side of the ravine, forms the cUffs ex- 

 clusively, and is mixed with a confused deposit, like indurated 

 mud, which would seem to have flowed out of the crater at the 

 same time, rather than to have resulted from decomposition. It is 

 in this basalt that the plomb natif volcanique" of M. Haiiy was found. 

 We next pass a basalt which is particularly scoriaceous and ceUidar 

 where it has reached the sea, and continuing, we observe that it 

 afterwards presents, in its more elevated parts, immense patches 

 and bands of earth, resembling tufa, and seemingly resulting from 



" " Araorphe, en masses contourn^es ;" there is a specimen in the cabinet of the 

 Jardin des Plantes, but not a vestige of it is to be met with in these rocks at present ; 

 and Don Joze de Vasconcellos, who was with M. Ratske when he found it, tells me. 

 that the quantity was exceedingly small, and that he never could discover any other 

 trace of it since, although he has frequently searched. Lead, galena, has since been 

 found in the basalt near Durham. 



I 



