Juke 29, lOOC] 



SCIENCE. 



965 



about twenty-five or possibly thirty miles 

 on either side of the rift. On the south- 

 west side the greater part of this area to 

 the north of the Golden Gate lies in the 

 Pacitic. This area extends from Eureka, 

 in Hiunboldt County, to the southern ex- 

 tremity of Fresno County, a distance of 

 about four hundred miles. 



Beyond this area of destructive shock 

 the earthquake was felt in its milder mani- 

 festations over a wide territory. Our re- 

 ports to date show that it was felt in 

 Oregon as far north as Coos Bay and on 

 the south as far as Los Angeles. To the 

 east it was felt over the greater part of 

 middle California and eastern Nevada, 

 particularly along the eastern flank of the 

 Sierra Nevada. It was felt at Lovelocks, 

 and we have unconfirmed reports of its 

 having been felt at Winnemueca. Far be- 

 yond the region within which it was ap- 

 parent to the senses, however, the earth 

 wave was propagated both through the 

 earth and around its periphery, and some 

 of the most valuable and most accurate 

 records of the disturbance which we have 

 are those which were registered at such dis- 

 tant seismographic stations as Washing-ton, 

 D. C. ; Sitka, Alaska; Potsdam, Germany; 

 and Tokyo, Japan. 



Within the area of destructive effects 

 approximately four hundred by fifty miles 

 in extent the intensity varied greatly. 

 There was a maximum immediately on the 

 rift line. Water pipes, conduits and 

 bridges crossing this line were rent asunder. 

 Trees were uprooted and thrown to the 

 ground in large numbers. Some trees 

 were snapped off, leaving their stiimps 

 standing, and others were split from the 

 roots up. Buildings and other structures 

 were in general violently thrown and other- 

 wise wrecked, though some escaped with but 

 slight damage. Fissures opened in the 

 earth and closed again, and in one case re- 

 ported a cow was engulfed. A second line 



of maximum destruction lies along the floor 

 of the valley system of which the Bay of 

 San Francisco is the most notable feature, 

 and particularly in the Santa Rosa and 

 Santa Clara valleys. Santa Rosa, situ- 

 ated twenty miles from the rift, was the 

 most severely shaken town in the state and 

 suffered the greatest disaster relatively to 

 its population and extent. Healdsburg 

 suffered to a nearly similar degree. San 

 Jose, situated thirteen miles, and Agnews, 

 about twelve miles from the rift, are next 

 in the order of severity. Stanford Uni- 

 versity, seven miles from the rift, is prob- 

 ably to be placed in the same category. All 

 of these places are situated on the valley 

 floor and are underlain to a considerable 

 depth by loose or but slightly coherent 

 geological formations, and their position 

 strongly suggests that the earth waves as 

 propagated by such formations are much 

 more destructive than the waves which are 

 propagated by the firmer and highly elastic 

 rocks of the adjoining hill lands. This 

 suggestion is supported by a consideration 

 of the destructive effects exhibited by towns 

 and single buildings along the same valley 

 line which are situated wholly or partly 

 on rock. Petaluma and San Rafael, 

 though nearer the rift than Santa Rosa, 

 suffered notably less, and they are for the 

 most part on, or close to, the rocky surface. 

 The portions of Berkeley and Oakland 

 which are situated on the alluvial slope 

 suffered more than the foothills, where the 

 buildings are founded on rock. The same 

 suggestion is further supported from a 

 consideration of the zone of maximum de- 

 structive effect on the . southwest side of 

 the rift. This zone lies in the Salinas 

 Valley. The intensity of destructive ac- 

 tion at Salinas was about the same as at 

 San Jose, and the town is situated on the 

 flood plain deposits of the Salinas River. 

 Along the banks of the Salinas River and 

 extending from Salinas to the vicinity of 



