EARTHQUAKES ON THE PACIFIC COAST 171 



1892. April 17; Olympic; 2:45 p. m. 



Severe. 



1892. April 17; Portland; 2:56 p. m. 



The observer of U. S. Weather Bureau reports one light shock. 



1892. April 19. 



On the morning of this day in the central portion of the State 

 occurred the heaviest eartliqual-ce of the year, and in the locali- 

 ties where it was most severe it was doubtless the worst ever 

 experienced, rivaling that of 1868 in severity, and probably exceed- 

 ing it in point of property destruction. Three important towns, 

 viz., Vacaville, Winters and Dixon, suffered severely and much 

 damage was done in the vicinity. The second day following 

 brought another severe shock which wrecked many buildings 

 already weakened. It is, perhaps, worthy of remark that these 

 disturbances did not follow the mountain contour of the country, 

 but seemed to have their greatest range east and west or nearly 

 at right angles to the direction of the mountain ranges; crossing 

 the Sierras, they were distinctly felt in Nevada. The loss of 

 property was great. — C. D. P. It is my opinion that this shock 

 was quite as severe as the San Francisco shock of 1868. — E. S. H. 



1892. April 19; Mount Hamilton. 



" Long period gentle shock — waked sleepers — swung hanging lamps 

 — R. F. = IV to V. 2.491/2 P. S. T." (Prof. Holden.) The record 

 on the duplex seismograph shows the greatest motion to have 

 been east and west, amounting to 18.5 mm.; the displacement 

 north and south amounting to 8 mm. 



1892. April 19; San Francisco; 21i. 50iu. a. ni. 



Sharp undulating shock S. W. and N. E. Duration 40 seconds. — 

 T. T. The shock was the heaviest experienced since the historic 

 one in 1868. 



The greatest result that the shake occasioned in San Francisco vras 

 the downfall of the front wall of the Old Academy of Sciences 

 building on the corner of Dupont and California streets. Work- 

 men were engaged in tearing it down. The roof and side walls 

 had been cut away, and to guard against a fall the wall was 

 braced with long timbers. When the quake came the timbers 

 w^ere shaken off and down came several tons of brick and mortar. 



The earthquake began with a thump that seemed to knock the earth 

 to the west, then for about three seconds the world seemed to be 

 sliding convulsively back into place. But before it came to rest 

 there was another thump, followed by a lighter one. Alto- 

 gether it took thirteen minutes for the earth to get over its flut- 

 tering. Prof. Davidson happened to be in his observatory. He 

 did not feel the earthquake, as he was just rising from his chair. 

 He knew it was a-quaking, however, by the excitement in the 

 bubbles of the levels. The time was 2.51.41 this morning. The 



