SO The American Geologist. Feb. 1891 
and in the center of the bell, then the latter would have had to in- 
cline about 23°, 17'. to have struck the former with sufficient 
force to have produced loud sounds. 
The diameter of the surface waves where the horizontal element 
was sufficientto he noted, was about 30 miles. The locus was about 
6,900 yards deep below the earth's surface: this was calculated 
from the curved seismal line extending through the places where 
the force at the surface was noticed to have been greatest, and from 
the probability that the diameter of the surface waves there, where 
the horizontal inclination was at greatesl angle with the declining 
oscillation and the locus, was the base of a cone whose apical 
angle was 70°, 32'. The strongest wave extended for about ::n 
miles into the Pacific ocean ; ;i few others extended about 20 
miles, and several only nine to twelve miles from Monticule Pilon 
on the line of greatest disturbance. 
The velocity of transit of the spherical waves through the not 
firmly compacted volcanic formation was about 6,000 feet per 
second. This was ascertained by three fortunate experiments, in 
similar materials between two stations 9,556 feel distant from 
each other mid aboul 200 feet deep in volcanic craters. The 
velocity of the surface waves was much greater than that of the 
spherical waves. 1 could not get reliable information. The tele- 
graph operators at the stations. Granada and Masaya, VI miles 
from each other on the railroad between lakes Nicaragua and Man- 
agua, were not sufficiently active, and the clocks did not corre- 
spond : but it was about 10,000 feet per second. 
The moon was about Syzygies : the season of the year, winter or 
rainy season, but unusually dry from lake Nicaragua to the Pacific 
ocean ; no com. grasses or vegetables had produced crops this 
season in the western third of Nicaragua. The remaining two- 
thirds of the country had an abundance of rain at this season of 
the year, as usual. In Managua, church bells were tolled and 
prayers for rain were ottered. The larger number of the earthquakes 
were felt during strong currents of wind. No unusual meterologi- 
cal phenomena were observed between the 3d and 12th inst. , 
although several earthquakes were experienced between those 
dates in the locality of the city of Granada. •Ila/.y. murky, 
atmospheric condition prognosticating earthquakes'" — 1 have fre- 
quently and anxiously looked for such a condition of the atmos- 
