Review of the Results of the U. 8S. Coast Survey. 83 
ined, the cotidal lines for the Pacific are either sensibly parallel 
to or make but a small angle with the coast. 
Tide tables for the principal sea ports of the United States 
have been published by the Superintendent of the Coast Survey 
by authority of the treasury department; they are based exclu- 
sively upon the observations of the survey, and will be extended 
and corrected as the survey advances. Meantime their value to 
navigators places then among the important results of the Coast 
The tidal observations of the Pacific coast have casually led 
to a determination of great scientific interest, that of the averag 
depth of the Pacific Ocean between the coasts of Japan a 
@ California. On the 23d of December 1854, an earthquake oc- 
: curred in Japan. by which the town of Simoda im the island of 
_  Niphon was destroyed. From the imperfect accounts which 
3 have reached us it appears that at 9 A. M. on that day the severe 
; shock of an earthquake was felt on board the Russian frigate 
Diana, then lying in the harbor of Simoda. Half an hour later 
‘he sea came into the bay in an immense wave thirty feet in 
height, overwhelming the town and then receding. This advance 
and recession occurred five times, and by 2°30 Pp. mM. all was again 
quiet. The depth of the sea during these changes varied 
less than eight to more than forty feet. Upon the same da 
4n extraordinary rise and fall of water was observed at Peel's 
Island, one of the Bonin Islands, and the tide continued to rise 
and fall during the day at intervals of 15 minutes, gradually 
lessening until evening. ee alg 
he self-registering gauges at San Diego and San Francisco, 
, 
Move at about the rate of 360 miles per hour or 6_ miles per 
Origin of the disturbance upon the 25th of December. 
(Zo be concluded.) 
