140 PROCEEDINGS OF THE CALIFORNIA 



years in this State, forty-eight have occurred during the spring, summer, aud 

 autumn months, and eleven during the winter months. 



Of the total number noted, twenty-seven have occurred from San Luis Obispo 

 south, and of the thirty-two remaining, nine have been felt in San Francisco at 

 the same time they were observed at San Luis Obispo, while the remaining 

 twenty-three were felt at San Francisco and north of that point. 



Notwithstanding we have had, what may, perhaps, be considered a frequency 

 in the recurrence of these phenomena, still there are but a very few of the total 

 number that would merit a moment's consideration south of the twenty-fifth 

 parallel of north latitude, for there they would be regarded as minor affairs 

 entirely. 



From all the facts in our possession relating to the phenomena on our coast, 

 it appears that the greatest preponderance in action and severity of effects, is 

 exerted, for the most part, south of Point Conception, for, from this place, east, 

 south and north, to near the Colorado, the most conclusive evidence exists of 

 very recent volcanic action having been exerted on rather an extensive scale, 

 and is also still persistent in several localities within the area named, though in 

 a minor degree. 



It would be interesting to examine the changes of level that have evidently 

 taken place in this State within the last five years ; but as more extended 

 observations would greatly assist us in forming conclusions on this subject, I 

 will defer that portion until a future day. 



1856. 



At the close of 1855, 1 presented to the Academy a statement of the occur- 

 rence of earthquakes in this State for that year and a term of years preceding. 



During the year just passed, I have kept a careful record of these phenomena, 

 which have been noticed in this city, and other parts of the State, and which will 

 be found below, with their date, and the hour of the day on which they took 

 place ; they comprise all that have occurred, with perhaps two exceptions, the 

 dates for which were so obscure as to render it impossible to determine with ac- 

 curacy the precise period of their occurrence. So far as I am informed, those 

 shocks that have taken place in this State during the past year have not been 

 marked with more severity than has been usual in years preceding, frequently 

 amounting to a slight tremor, and at other times to more distinct movements ; 

 three only have possessed sufficient intensity as to command general attention 

 during the busy hours of day. 



Very few have been noticed by persons who were standing upon the earth at 

 the period of their occurrence. By far the greater proportion were observed in 

 high situations from the ground, and in the more retired parts of the city, or on 

 the alluvial covering of the country to the west aud south. 



The total number for the past year is sixteen, and of this number thirteen 

 were observed between sunset and sunrise. 



By reference to the statistics below, it will be seen that even mountain districts, 

 where during the day there is much less of turmoil and noise arising from busi- 

 ness than in the populous city, that of all those noticed, none have been of suf- 



