ACADEMY OF NATUKAL SCIENCES. 135 



This period of time seems analogous in some respects to the year 1852, and 

 was one of very marked severity on this coast, as was also the latter year ; it 

 was analogous to other periods of subterranean disturbance in other parts of the 

 earth since the historic era began, and there is no good reason why we may not 

 look for the recurrence of similar events in future time. But we must not lay 

 too much stress on the destruction of the two mission churches in 1812, to 

 guide us in an estimate of the force of this earthquake, for the construction of 

 those buildings had but little relation to similar structures of modern date, 

 either in strength or material. 



From 1812 to 1850, the archives are silent on this subject. In the latter year 

 our record began and has continued with little interruption to 1863, a period of 

 thirteen years. Within that period there are but few earthquakes occurring 

 north of the thirty-ninth parallel which have escaped notice and have not 

 been made matter of record. 



1850. 



During this year the following earthquakes were recorded : 



March 12th. — A light shock was felt in San Jose. 



May 13th. — A light shock in San Francisco. An eruption of Mauna Loa, S. 

 I., and shock same day. 



June 28th. — A light shock in San Francisco. 



August 4th. — A smart shock was felt in Stockton and Sacramento. 



September 14th.- — Smart shock at San Francisco and San Jose. Total num- 

 ber recorded in 1850, five. 



1851. 



May 15th. — Three severe shocks in San Francisco. During this earthquake 

 windows were broken and buildings severely shaken. A large amount of 

 merchandize was thrown down in a store on California Street. The shipping 

 in the harbor rolled heavily. An eruption of Mauna Loa and shock in the 

 Sandwich Islands same day. 



May 17th. — A light shock in San Francisco. 



May 28th. — A light shock on the Salinas. 



June 13th. — A smart shock at San Francisco. This was felt at San Luis 

 Obispo and San Fernando. 



December 2d. — A shock at Downieville. 



December 31st. — A smart shock at Downieville. Total recorded in 1851, six. 



1852. 



From the beginning of this year until the middle of its last quarter, no dis- 

 turbances of the coast was noted until the month of November. In this month 

 the southern portion of the State was violently disturbed. 

 November 26th. — The number of shocks on this day at San Simeon was eleven, 



and at Los Angeles and San Gabriel the same number. Nearly or quite the 



same number was also observed by parties having in charge a Government 



train in transit from Fort Yuma to San Diego. 



This earthquake or the series was experienced over the entire country, east 



