VOLCANCITOS OF TURBACO. 319 
much credit to this tradition, the philosophers de- 
sired their guides to lead them to the spot. After 
traversing a space of about 5300 yards, covered with 
trunks of Cavanillesia, Piragra superba, and Gy- 
rocarpus, and in which there appeared here and 
there projections of a limestone rock containing pe- 
trified corals, they reached an open place of about 
908 feet square, entirely destitute of vegetation, 
but margined with tufts of Bromelia karatas. The 
surface was composed of layers of clay of a dark- 
gray colour, cracked by desiccation into pentagonal 
and heptagonal prisms. The volcancitos consist of 
fifteen or twenty small truncated cones rising in the 
middle of this area, and having a height of from 
19 to 25 feet. The most elevated were on the south- 
ern side, and their circumference at the base was 
from 78 to 85 yards. On climbing to the top of these 
mud-voleanoes, they found them to be terminated 
by an aperture, from 16 to 30 inches in diameter 
filled with water, through which air-bubbles ob- 
tained a passage; about five explosions usuaily tak- 
ing place in two minutes. The force with which 
the air rises would lead to the supposition of its 
being subjected to considerable pressure, and a 
rather loud noise was heard at intervals, preceding 
the disengagement of it fifteen or eighteen seconds. 
Each of the bubbles contained from 12 to 144 cubic 
inches of elastic fluid, and their power of expansion 
was often so great that the water was projected 
beyond the crater, or flowed over its brim. Some 
of the openings by which air escaped were situated 
in the plain without being surrounded by any pro- 
minence of the ground. It was observed that when 
the apertures, which are not placed at the sum- 
mit of the cones, and are enclosed by a little 
