SHOCKS AT SEA. 
459 
mark, that it seemed muck louder to persons out at sea, 
and at a great distance from land, than to those within sight 
of land, and near tlic burning volcano. 
The distance in a straight line from the volcano of St. 
Vincent to the Rio Apure, near the mouth of the Nula, is 
two hundred and ten leagues * The explosions were conse- 
quently heard at a distance equal to that between Vesu- 
vius and Paris. This phenomenon, in conjunction with a 
o-reat number of foots observed in the Cordilleras of the 
Andes, shows that the sphere of the subterranean activity of 
a volcano is much more extensive than we should be disposed 
to admit, if we judged merely from the small changes 
effected at tho surface of the globe. The detonations heard 
during whole days together in the New World, eighty, one 
hundred, or even two hundred leagues distant from a crater, 
do not reach us by the propagation of the sound through 
the air; they arc transmitted by the earth, perhaps in the 
very place where we happen to be. If the eruptions 
of the valeano of St. Vincent, Cotopaxi, or Tuuguragua, 
resounded from afar, like a cannon of immense magnitude, 
the noise ought to increase in the inverse ratio of the dis- 
tance : but observations prove, that this augmentation does 
not take place. I must further Observe, that M. Bonpland 
and I, going from Guayaquil to the coast ot Mexico, 
crossed latitudes in tho Pacific, where the crew of our ship 
were dismayed by a hollow sound coming from the depth of 
the ocean, and transmitted by the waters. At that time a 
new eruption of Cotopaxi took place, but v e weie as foi 
distant from the volcano, as Etna from the city of Naples. 
The little town of Honda, on the banks of the Magdalena-, 
is not less than one hundred and forty-five leagues! from 
Cotopaxi ; and yet, in tho great explosions of this volcano, 
iu 1744, a subterranean noise was heard at Honda, and 
supposed to be discharges of heavy artillery. The monks 
of San Trancisco spread a report that the town of Cnr- 
tharnma Whs besieged and bombarded by the English; and 
thcMiitelligenco was believed throughout the country. Now 
* Where the contrary is not expressly stated, nautical leagues ol 
twenty to a degree, or trvo thousand eight hundred and fifty-five toises, 
xi q always to be understood. 
f This is the distance from Vesuvius to Mont Blanc. 
