.895] 557 [Crawford. 
accumulate and remain in the cauldrons beneath Cen-o Yiejo where 
it oi-iginates, would cause frequent volcanic outbursts from the 
craters of the Cerro, is removed by convection and other pro- 
cesses into this extensive submarine accumulating deposit of sedi- 
mentary materials, and thus the volcanoes are relieved from 
activit}^ The shore line of this subsiding area has lowered nearly 
two feet since the early part of 1 881, as measured by comparing the 
present altitude of a railway on that coast with its altitude when 
first constructed in 1881. (5) Undulatory movements of the 
land surface between the ocean and the Cerro have been noticed 
on several occasions, the entire oscillation of depression and re- 
elevation being at one time nearly 20 inches. 
The evidences noted by the author of the existence of exten- 
sive, deeply-located, deep caverns beneath the volcanic belt in 
western Nicaragua, and the methods used to ascertain or rather 
estimate their dimensions and depth beneath the earth's surface, 
and the evidence of the origin in them of a large number of the 
earthquakes felt in that part of Nicaragua, will be considered in 
another paper. It would be quite difficult to account satisfactorily 
for the very large and continuous flow of waters from beneath 
Cerro Viejo. Otherwise than that, these waters are hydrothermal 
vapors developed in caverns beneath the Cerro and are condensed 
into Avater while on their way to the earth's surface from the 
highly heated subvolcanic cauldrons. 
