136 EARTHQUAKES ON THE PACIFIC COAST 



1889. June 6; 8:30 p. m. 



San Bernardino: noticed by some persons, but not by all. A single 

 shock from northeast to southwest, with some vertical motion. 

 A few persons report rumbling noises. Times of occurrence vary 

 somewhat; 8.14 given bj^ one person. Estimated intensity (III). 

 — W. C. Parmley. There was quite a shock of earthquake in this 

 city last evening at about 8.30. The shock was accompanied by 

 a low rumbling, and the vibrations were northeast to southwest. 

 — San Bernardino, Daily Times-Index, June 7. 



1889. June 9; 3:44:24 ± 3 p. m. 



Mount Hamilton: very slight shock (I) noticed by J. E. Keeler, 

 not by others. Vibrations lasted a few seconds. A small record 

 was made on the duplex seismograph. 



1889. Jnne lO; 7:33:7 a. m. 



Mount Hamilton: very slight shock recorded on both seismographs, 

 but not felt by anybody (II). Measurement of the record on the 

 Ewing seismograph gave the following data: Duration = twenty- 

 four seconds; maximum double amplitude (magnified) east and 

 west =: 0.52 millimeter; maximum double amplitude (magnified) 

 north and south ^ 0.38 millimeter; maximum double amplitude 

 (magnified) vertical = very small; period of complete vibration 

 = about one-half second. Hence computed intensity is 12 or (I) 

 of Rossi-Forel scale. 



1889. June 19; 10 p. ni. 



Lassen County, California, and Nevada: this shock, which does not 

 appear to have been felt in the central and southern parts of Cali- 

 fornia, is thus described in the Susanville Advocate: 



Since the 19th instant the peof)le of Susanville, Lassen County, have 

 felt about seventy-five slight shocks of earthquake. The first 

 shock occurred at 10 o'clock on the night of the 19th, and was 

 the heaviest ever experienced in this section. The first great 

 shock was followed at greater or less intervals by more or less 

 heavy shocks for over two hours, until twenty-eight shocks had 

 been recorded, of which the first, the thirteenth, the fifteenth, 

 and the eighteenth were very severe. At the first shock, which 

 vpas something fearful, rocking buildings from side to side and 

 scattering crockery and glassware in all directions, people rushed 

 out of houses with the costume, principally, that nature had pro- 

 vided for them (VII). The vibrations were from south to north, 

 but apparently did not extend much north of Susanville. The 

 shocks were generally preceded by distinct rumbling noises. 



Chico: a slight earthquake shock was experienced here last even- 

 ing about 10 o'clock. Vibrations from east to west. 



Sacramento: at 10.12 last night a slight shock of earthquake was 

 felt here. It lasted but a few seconds, and was felt by only a 

 few persons. 



