IN OTHER DISTRICTS. 165 
flowed, and after a course of four hours reached the 
sea. The explosions resembled alternate volleys 
of very large cannon and musketry. As the space 
between the voleano of St Vincent and the Rio 
Apure is 725 miles, these were heard at a distance 
equal to that between Vesuvius and Paris, and 
must have been propagated by the earth, and not 
by the air. 
After adducing numerous instances of the coinci- _- 
dence of volcanic eruptions and earthquakes, Hum-~ 
boldt endeavours to prove that subterranean com- 
munications extend to vast distances, that the phe- 
nomena of volcanoes and earthquakes are intimately 
connected, and that the latter have certain lines of 
direction. 
