160 EAETHQUAKES ON THE PACIFIC COAST 



Mayfield: " a slight shock of earthquake was felt here at 3 o'clock 

 this morning. It lasted four seconds. Trembling vibrations were 

 followed by two shocks." — S. F. Chronicle. 



1891. Jnne 29; Mount Hamilton; 8:06:31 ± 2 a. m. (\V. W. Campbell); 

 8:06:32 (J. M. Scbaeberle). 



One quick shock lasting for less than half a secoud; Rossi-Forel 1 

 or II. " Eecorded on duplex, but not on Ewing seismometer." 



1891. July 12; Berkeley. 



Slight record on duplex instrument. — Professor Soule. 



1891. July 13; Monterey; 4:27 p. m. 



A sharp shock with vibrations from southwest to northeast. 

 Clocks were stopped and crockery thrown from the shelves (VI). 



1891. Jnly 13; Santa Crnas Liightbowse; 4:261/2 p. m. 



Duration about two seconds. (Ms. of U. S. Geological Survey.) 



1891. Jnly 17; Hollister; 1 a, m. 



Quite a severe shock; no damage. 



1891. Jnly .30. 



Lerdo, Mex., was the center of a very severe earthquake about 6 

 o'clock a. m. It appears to have caused a tidal wave of con- 

 siderable height at the head of the Gulf of California. The coun- 

 try is so thinly and poorly settled that no damage was done. 

 The reports of this earthquake are so indefinite and contradic- 

 tory that we have little reliable information regarding what must 

 have been at least a very widespread disturbance. 



1891. Angrnst 9; Monterey; 9:41 a. m. 



A heavy shock, causing buildings to rock. The vibration was from 

 north to south. 



1891. Ansnst 9; 9:42 a. m. 



Santa Cruz Lighthouse: duration 2 seconds. (Ms. of U. S. Geolog- 

 ical Survey.) 



1891. August 11; Humboldt liigbtbouse. 



Three shocks in rapid succession, (1) at 3h. 18m. 30s. a. m., (2) at 

 3h. 18m. 20s., (3) at 3h. 18m. 5s. (sic). N. B. — All the ximes at this 

 station are from a clock which is regulated by the (calculated) 

 times of sunrise and sunset. (Ms. kindly communicated by the 

 U. S. Geological Survey.) 



1891. September? 



Tacoma, Washington, II, several shocks. — P. 



1891. September lO; Berkeley. 



Very distinct record, E. S. E. and W. N. W. — Professor Soule. 



