30 EARTHQUAKES ON THE PACIFIC COAST 



That is twenty-nine exceptionally heavy shocks (exclusive of 

 what I have called destructive shocks) have occurred since 1800, 

 or say, one every three and three-tenths years on the average, 

 taking the whole region of many thousand square miles together. 

 For any particular locality the number of really heavy shocks is 

 quite small. Thus, at San Francisco there have been three de- 

 structive shocks and four exceptionally heavy earthquakes in one 

 hundred years, although there have been very many slight shoclcs 

 and tremors. 



If we confine our attention to any other particular part of the 

 State, the number of really heavy shocks occurring is very small 

 indeed. When we take into account the whole damage to life and 

 property produced by all the California earthquakes recorded, it 

 is clear that the earthquakes of a whole century in California have 

 been less destructive than the tornadoes or the floods of a single 

 year in less favored regions. 



Edwaed S. Holden. 



Lick Observatory, University of California, 

 December 31, 1896. 



Hi 



THE EARTHQUAKE AT POMPEII, A. D. 62. 



