AVEKAGE OF DEPTH. 
15 
prise cannot be denied, particularly by having recourse to 
tunnels, or subterranean canals. The progressive retreat ol 
the waters has given birth to the beiutiful. and liu.uriant 
plains of Maracay, Oura, Moeundo, Guigue, and Santa Cruz 
del Escoval, planted with tobacco, sugar-canes, coffee, indigo, 
and cacao ; but how can it he doubted for a moment that 
the lake alone spreads fertility over this country ? If de- 
prived of the enormous mass of vapour which the surface 
of the waters sends forth daily into vhe s-mosphere, the 
valleys of Aragua would become as dry and barren as the 
surrounding mountains. 
The mean depth of the lake is from twelve to fifteen 
fathoms ; the deepest parts are not, as is generally admitted, 
eighty, but thirty-five or forty deep. Such is the result of 
soundings made with the greatest care by Don Antonio 
Manzano. AY hen we reflect on the vast depths of all the 
lakes of Switzerland, which, notwithstanding their position 
in high valleys, almost reach the level of the Mediterranean, 
it appears surprising that greater cavities are not found at 
the bottom of the lake of Valencia, which is also an Alpine 
lake. The deepest places are between the rocky island of 
Burro and the point of Cana Vistula, and opposite the high 
mountains of Mariara. But in general the southern part 
ot the lake is deeper than the northern ; nor must wo forget 
that, if all the shores be now low, the southern part of the 
basm is the nearest to a chain of mountains with abrupt 
declivities; and we know that even the sea is generally 
deepest nliere the coast is elevated, rocky, or perpendicular. 
The tempei aturc ol the lake at the surface during my 
abode in the valleys of Aragua, in the month of Bebruary, 
was constantly from 23° to 23'7°, consequently a little below 
the mean temperature ef the air. This may be from the 
effect ot evaporation, which carries off caloric from the air 
and the water ; or because a great mass of water does not 
follow with an equal rapidity the changes in the tempera- 
on its southern declivity, no point of level corresponding to 
i t .°^ ses ) except near San Juan. The absolute height of this village 
s 94 toisep. But. I repeat that, farther towards the west, in the country 
e .ween the Cano de Cambury and the sources of the Rio Pao, which I 
as not able to visit, the point of level of the bottom of the lake is much 
lurther north. 
