SAN SALYADOE. 



247 



basin six miles east of the capital, about 1 ,600 feet above tbe sea, encircled by steep 

 rocky shores. The lake, which has an area of 24 square miles, has frequently 

 changed its level, and towards the middle of the eighteenth century it was much 

 lower than at present. But after a series of landslips its eastern emissary, which 

 flows in a deep barranca to the Jiboa, a direct affluent of the Pacific, was dammed 

 up, thus causing a considerable rise in the level. In 1873, the lake was 

 violently agitated and raised about three feet above its normal level, and in 1879, 

 a fresh disturbance was followed by another rise of four feet. 



Then the waters overflowed their banks, and rapidly excavated a channel, 



Fig. 106.— Lake IiorANGO. 

 Scale 1 : lîO.OOO. 





,t^ 



Aest 01 Greenwich 



89° 



Sr"e: 



1) to 50 

 Fathoms. 



Denth'. 



50 to 100 

 Falhoms. 



100 Fathoms 

 and upwards. 



3 Miles. 



whereby a subsidence of eight feet was effected in three hours. In 54 days there 

 was a total fall of 35 feet, the volume discharged being estimated at over 20,320 

 million cubic feet. The noxious vapours which at first accompanied these convul- 

 sions were followed by discharges of lava, and islets composed of eruptive matter 

 rose gradually above the surface of the seething waters. But when all was over 

 nothing remained except an island of hard lava 160 feet high, in the immediate 

 vicinity of which the sounding- line revealed a depth of over 100 fathoms. 

 During the eruption the geologist Goodyear recorded no less than 440 violent 

 shocks. 



