Crawford.] 554 I May is. 
Till- (liftVreiit salts with wliicli several of t.Iie springs are im- 
pregnated indicate tliat theii* watei's pass tlirouoli se|)arately and 
dilTerently mineralized formations on tlieir way from beneath the 
Cerro to the surface of the earth ; and the very large quantity of 
water tliat flows continuously even in the dryest season (which 
lasts several months of each year) gives strong evidence that 
these waters are aqueous vapors condensed and usually differently 
mineralized in their passage from extensive caverns or grottoes 
deeply excavated beneath the Cerro, and consequently that these 
caverns are full of high tension aqueous vapors. 
Depressions of land or sunken areas. — Between the calcareous 
springs above mentioned and the foot of the cones Obraje and 
San Lorenzo are five sunken areas, four of which are from 80 to 
•200 feet wide, from 400 to 1,000 feet long, and from 150 to 200 
feet deep ; their floors are inchned downward toward the base of 
the cones. These depressed areas are not craters of volcanoes, 
but most probably are local subsidences of the hard rocks and 
lavas toward the caverns beneath the Cerro. The fifth depressed 
area is about 1,800 feet long, 500 feet wide, and contains a lake 
(Laguna Celinde) of potable water that is over 300 feet deep (its 
depth has not been ascertained). This lake has an ebb and flow 
movement every two hours (about), and appears to increase but 
little by rains and decrease very little by evaporation, and to be 
connected with or influenced by the aqueous vapors in the caul- 
drons beneath the Cei-ro. The rocky western walls of this de- 
pression have numerous sharp, projecting fragments, and the 
lamination is contorted, indicating twisting movements during a 
rapid severance of the rocks as a part of them descended to 
greater depths. 
On the southern side of Cerro Viejo are the four large de- 
pressed areas described below, whose floors incline downwards 
beneath the Cerro ; as if the rocky materials that once occu[)ied 
and filled these depressions had descended into some previously 
excavated cavern. 
1. Hojo del Padro, near the base of the cone Uval, is al)out 
300 feet deep and covers abo«t twelve acres of ground ; its floor 
is covered with " granier nois " and lapilli, and it sustains a con- 
stant growth of grasses and small trees, although water is found 
