EARTHQUAKES ON THE PACIFIC COAST 13 



Mills College; 11:5 p. m. 



Alameda. Mr. Perrine's seismograph gives a record of an extensive 

 shock. Waves clearly marked into east and west, north and south, 

 and southeast and northwest. 



College Park; 11:10:39 p. m. 



Berkeley. Ewing seismograph records only one shock although 

 two were felt by many persons. ' ' The disturbance commenced 

 with minute vibrations in all three components, which gradually 

 increased in the north-south and the east-west components, reach- 

 ing a first maximum in the east-west direction at thirty-seven 

 seconds (reckoned from the beginning), and a second and principal 

 one at seventy-two seconds. The principal disturbance in the 

 north-south direction commenced at about thirty-two seconds and 

 lasted to the fiftieth second. During this interval the intensest 

 vibration occurred at forty-nine seconds, almost exactly from 

 south to north. . . ." "By treating the displacement as be- 

 longing to a simple harmonic motion, the actual velocity of the 

 ground at forty-nine seconds is found to be 0.47 inch (12 mm.) 

 per second, and its actual acceleration 1.29 inches (33 mm.) per 

 second. . . . The velocity of the greatest westerly displace- 

 ment is 0.13 inches (3 mm.) and acceleration 0.32 in. The greatest 

 displacements were north-south 0.34 inch; east-west 0.10 inch." — 

 Prof. A. O. Leuschner. 



1898. April 16; Crescent City; 5:40 a. m. E.-F. Ill or IV. 



1898. April 18; Prairie Camp (Mendocino County). Nine severe shocks. 

 Possibly the shocks of April 14. 



1898. April 21; Descanso. 



1898. April 25; Albion, Mendocino. Severe shock. 



1898. April 26; College Park; 10:30 p. m. Eeeorded on seismograph and 

 also felt. (Explosion of Santa Cruz powder works (?).— C. D. P.) 



1898. April 30; Claremont, Pomona. 



1898. May 2; College Park; 6:2 a. m.— H. D. Curtis. 



Salinas. Two distinct shocks at 6:5 a. m. 



Santa Cruz. 

 1898. May 9; Gilroy, about 7 a. m. Light. 

 1898. May 17; Cedarville. 

 1898. May 19; Cedarville. 

 1898. May 20; Lick Observatory. Light shock; 6:48:53 a. m. 



College Park; 6:49 a. m.— H. D. Curtis. 



