116 The American Geologist. August, i892 
The facts obtained, in reference to this earthquake, to date — 
the sailing of the weekly Mail S. ship from the port of Covinto — 
5 o'clock p. m., 9th February, 1892, are: 
Only one series of vibrations has occurred. The epicentrum 
was near the island of Zapatera at the west coast of lake Nicara- 
gua, distant about 14 miles east from the Pacific ocean and about 
28 miles southeast from the city of Granada. 
The focus has not yet been determined, but was more than 
15,500 feet (English) beneath a plane parallel with the sub-areal 
surface of the Pacific ocean. 
The co-seismal lines of emergence of the waves, at the earth's 
surface, were elliptical, but converging at several places toward 
the longitudinal axis of the ellipsoid. 
The maximum of the horizontal element of the oscillations, or 
line of greatest disturbance at the earth's surface was, on the 
northwestern side of the epicentrum, in lake Managua, about 65 
miles distant from the point of first emergence, 30 miles west- 
ward from the city of Managua, and about 36 miles southeast 
from the citj" of Leon. 
The rate of transit through the earth during the latter or vi- 
brating part was about 29 miles per minute. 
The greatest vibration, in the city of LecSn, from a line p'er- 
pendicular to and at an altitude of 60 feet above the surface was 9° 
25' about. 
Several adobe walls of houses in the cities of Granada, Mana- 
gua, and Leon were slightly cracked, or, these walls (usually 2\ 
to 3 feet (English) thick and 14 to 18 feet high) were disconnected 
from similar ones connected at right angles, i. e. , those extend- 
ing north and south were slightly disconnected from those ex- 
tending east and west. 
The city of Managua being nearer the coseismal line of great- 
est force expressed at the surface than the other cities named 
felt this earthquake more severely. In the city of Leon, the 
locality of the longest ordinates of the curvatures, or apex of 
elevation and depression, were easily discovered by finding the 
walls of houses that had been slightly displaced or cracked by 
the waves. 
During the first 60 seconds the oscillations were about one each 
six seconds — causing a sensation as if they had originated from 
the impact against the hard floor of some deep seated cavern of 
