28 eakthquakes on the pacific coast 



Conclusion. 



From the report of United States Surveyor-General Harden- 

 burg, for the year ending June 30, 1871, the following is extracted: 



" The shocks of 1800, 1808, and 1812 in California appear to 

 have been about equal in force to the shock of 1868 (and it seems 

 there have been no shocks during a century of greater severity). 



" It is fair then to consider the shock of 1868 as a standard of 

 the maximum force of earthquakes occurring in California during 

 the last one hundred years. On the hypothesis that earthquakes 

 are the results of natural laws, which operate with some degree of 

 regularity, it may be fairly presumed that a period of one hundred 

 years would, in all probability, give the extreme limit of the result 

 of the action of these laws. Hence, having learned from reliable 

 history and from observation the maximum strength of earthquakes 

 occurring in California during a century past, we may, from these 

 data, with some degree of confidence predict what their maximum 

 strength will probably be during the hundred years to come. It 

 will perhaps be no difficult matter to provide against any serious 

 damage from these unwelcome visitors, by so constructing build- 

 ings that they shall be proof against any such shock of earth- 

 quake as has occurred in California during the last hundred years. 

 Eeasoning from the foregoing historical facts, I am firmly of the 

 opinion that the earthquakes of California are not so much to be 

 dreaded as is generally supposed; in fact, that they are far less 

 dangerous to life and property than are the hurricanes of the 

 South or the summer tornadoes of the North." 



The earthquake of 1872, which occurred subsequent to the writ- 

 ing of this report, was far more severe than the shock of 1868, and 

 should be taken to represent the maximum severity of any shock 

 wJiich has actually occurred in California during a century. 



The destructive earthquakes on the Pacific Coast during the years 

 1769 to 1887 have been those of: 



1800. October 11-31 (San Juan Bautista, etc.). 



1812. October or December (San Juan Capistrano). 

 1818. ? (Santa Clara). 



1836. June 9 and 10 (Monterey and northward). 

 1839. ? (Redwood City and San Francisco). 



1857. January 9 (Ft. Tejon, Tulare, etc.). 



