38 
BASAT/rre KOC-KS. 
modern charts call the West Rock (Roca del Oeste), was 
raised hy volcanic fire ; and it might heretofore have been 
much higher ; for the new island of the Azores, which rose 
from the sea at successive periods, in 1G38 and 1710, had 
reached 354 feet when it totally disappeared in 1723, to the 
depth of 480 feet. This opinion on the origin of the basaltic 
mass of the Infierno is confirmed by a phenomenon, which 
was observed about the middle of the last century in these 
same latitudes. At the time of the eruption of the volcano 
of Temanfaya, two pyramidal hills of lithoid lava rose from 
the bottom of the ocean, and gradually united themselves 
with the island of Laucerota. 
As we were prevented by the fall of the wind, and by the 
currents, from repassing the channel of Alegranza, we 
resolved on tacking during the night between the island of 
Clara and the West Rock. This resolution had nearly proved 
fatal. A calm is very dangerous near this rock," towards 
which the current drives with considerable force. We began 
to feel the effects of this current at midnight. The proxi- 
mity of the stony masses, which rise perpendicularly above 
the water, deprived us of the little wind which blew : the 
sloop no longer obeyed the helm, and we dreaded striking 
every instant. It is difficult to conceive how a mass of 
basalt, insulated in the vast expanse of the ocean, can cause 
so considerable a motion of the waters. These phenomena, 
worthy the attention of naturalists, are well known to 
mariners ; they are extremely to be dreaded in the Pacific 
ocean, particularly in the small archipelago of the island; 
of Gallipagos. The difference of temperature which exists 
between the fluid and the mass of rocks does not explain the 
direction which these currents take ; and how can we admit 
that the water is engulfed at the base of these rocks, (which 
often are not of volcanic origin) and that this continual 
engulfing determines the particles of water to fill up the 
vacuum that takes place. 
The wind having freshened a little towards the morning 
on the 18th, we succeeded in passing the channel. Wo 
drew very near the Infierno the second time, and remarked 
the large crevices, through which the gaseous fluids probably 
doubt because the Guanches considered the peak as the entrance into 
hell. In the same latitudes an island made its appearance in 1811 . 
