952 Recent Literature. [ November, 
which cause the rattling and vibrating jars so often noticed on 
board ships. 
But out of 15,000 earthquakes observed on coast lines, only 124 
were accompanied by sea-waves. Out of 1098 recorded on the 
west coast of South America only nineteen are said to have been 
accompanied by sea-waves ; but from additional facts stated, almost 
every severe earthquake on that coast has been accompanied by 
considerable agitation in the neighboring sea. 
“ On April 2, 1851, when many towns in Chili were destroyed, the 
sea was not disturbed. At the time of the great earthquake of 
New Zealand (June 23, 1855), although all the shocks came from 
the sea, yet there was no flood. The small shock of February 14, 
however, was accompanied by a motion in the sea.” To these 
facts, taken from Fuchs’ work, our author adds the fact that the 
Fig. 2.—Stud mill at Haywards, California, swung completely over. 
greater number of disturbances which are felt in the northeast 
of Japan, although they emanate from beneath the eos 
not produce any visible sea-waves. They are, however, Su 
š x 3 ir 
to cause a vibratory motion on board ships situated near thet 
It has been long known by physicists that the velocity with 
vhich a given wave is propagated along a trough of -e x a 
depth, holds a relation to the depth of the trough; hence ca gwi 
tions of the average depths of the Pacific, dependent on e yar’ 
ity with which earthquake waves have been propagatee, aie 
een made by many investigators, but Milne thinks mo 
-open to criticisms in consequence of the writer having EE 
~ thatthe wave originated on a coast line, when the evidence c ines 
_ showed that it originated some distance out at sea. Asan d of 
_ ple of such calculations we copy Milne’s account of the wa , 
n ap e 
“On August p1, 1868, a sea-wave ruined many cities OF the 
