52 Gilbert — The California Earthquake. 



The volume closes without discussing the subject of future 

 earthquakes in the San Francisco region, but furnishes material 

 pertinent to that discussion by publishing accounts of the earth- 

 quakes of 1868, 1865 and 1857. The fault in 1857 was on the 

 southern part of the San Andreas rift, and the fault in 1865 

 may have been on the same rift near the southern end of the 

 fault of 1906. The fault in 1 868 was on a parallel rift east of the 

 southern arm of San Francisco bay. In each case the distri- 

 bution of intensity in San Francisco was substantially the same 

 as in 1906, the character of the ground having more influence 

 than the direction of the origin. 



The second and closing volume of the report will be by H. 

 F. "Reid, and will treat of the theory of the seismogram. 



