Crawford.] 552 [May 15, 
About 3 miles southwest of the foot of San Lorenzo, the Chi- 
uandega River, a stream of warm water over 20 feet wide and 2 
inches deep at its origin, issues from between horizontal strata of 
lava. It rapidly increases in volume for the first 2 miles of its 
length, and after flowing for a distance of about 25 miles in a 
tortuous course, empties into the estuary of Ascedadores, near the 
island of that name. 
Three miles north of the head of the Chinandega River, at the 
western termination of Cerro Viejo, there is a group of large 
springs whose waters unite and form the Rio Viejo, a larger river 
than the Chinandega. About 5 miles farther north is another 
group of large springs which unite within 200 feet of their out- 
pour from fissures and form the Rio Atoya, a river about twice 
the size of the Viejo. These two rivers flow nearly parallel and 
discharge their water, sand, and silt into the Ascedadores. The 
caverns whence the waters of these three rivers are condensed 
are evidently the same ; they are similarly but slightly mineral- 
ized, and their heads are only three or four miles distant from the 
western termination of the group of cones at the western end of 
Cerro Viejo. 
About G miles north of the group of springs that form the Rio 
Atoya and at about the same distance northwest of the base of 
the massive cone of rock materials called Obraje, are several 
large springs about 80° C. which are nearly saturated with bicar- 
bonates, principally of calcium. All these springs are similai-ly 
mineralized, and are evidently from the same underground con- 
duit, and, most probably, from the caverns or grottoes ^beneath 
the cone Obraje. They at once unite and form a shallow creek 
from 50 to 60 yards wide, which occasionally from excessive out- 
pourings overflows the low wide valley on each side. These 
waters on cooling deposit calcium carbonate, forming large masses 
of travertine and onyx, while the rocks, leaves, and all detached 
vegetation over which they flow are encrusted, and accurate and 
beautiful casts and moulds are thus made. The waters evi- 
dently pass in fissures through the strata of magnesian limestone 
of Paleozoic era referred to above; or they flow in fissures 
through some bed of hmestone rock or large deposit of shells or 
coral. The travertine and onyx are often in continuous deposits 
