Surmhit of the Peak of Tenctiffe. 39 



carried before it without breaking : \ve had not time to tra- 

 verse it before sun-set. The declivity of the ground, and 

 the darkness, rendered our march exccedin^rly painful till 

 we reached the first habitations ; where our guide soon kin- 

 dled some pieces of split fir-wood, by the light of whicli 

 we contmued our route ; and arrived at the port of Orotava 

 at nine in the evening. I found my friends uneasy at my 

 long delay ; they had distinctly observed the flag whicli I 

 hoisted in the morning. 



I have not time to add any thing further to this sketch of 

 one of the most interesting journeys that those who occupy 

 themselves with the stmcturc of the globe can undertake. 

 Since that time I have not neglected any opportunity of 

 multiplving or verifying my observations- I have collected 

 the most sing-ular notions in regard to the internal compo- 

 fition of more than 600 modern currents of lava. What 

 would become of our numerous systems in regard to volca- 

 noes, if it be ti-ue that we have hitherto been acquainted 

 only with the superficial part of their productions, scorise 

 and porous lava ? This is as if we were to judge of different 

 iiquors without seeing any part of them but the foam. 



The erup'.ion which choked up the port of Guarachico 

 in 1 706 was attended with this peculiarity, that the current 

 traversed sixteen leagues in five hours: the extremity of it 

 has been carried away by the sea. One may observe that it 

 is composed of prismatic basaltes, black and somewhat 

 porous, with large crystals of augite and olivin. 



The last eruption took place in 1 798. New mouths, 

 three in number, were opened on the declivity of an enor- 

 mous prolongation of the base of the peak towards the south- 

 west, 1270 toises above the level of the sea. As the form of 

 the mountains on this side justified mv regret, I made every 

 tflbrt to repair my fault ; and I can now say, that of all the 

 travellers who preceded me, I ascended quietly for three 

 hours along the declivities of the prolongation. When I 

 reached the height of IGOO toises I found myself on the 

 edges of a vast crater, to which none of those we are ac- 

 quainted with can be compared : it is nearly a league and a 

 half in circunilerence. Tliough vcrv old, it is exceedingly 

 steep iw the jnside, and still exhibits the image of the most 

 tlriadlul violence of the subterranean fires. The peak has 

 been raised on the edges of ihis intmensc mouth. The im- 

 possibility of walking round the summit of the peak, 01' 

 rather the custom \\ hich travellers have of exactly following 

 Jhe traces of their predecessors, is no doubt the cause of 

 'fljls curioijs {kit having hitherto rcm^ued unknown. 



C 4 My 



