ACADEMY OF NATURAL SCIENCES. 143 



March 31st, 13h. 25m. — A light shock was felt in San Francisco. It consisted 



of three light but distinct tremors. 

 April 6th, 23h. 30m. — A smart shock was felt at Los Angeles and the Monte, 



people were aroused from their beds. 

 May 10th, 21h. 10m. — A light shock was felt in San Francisco. The shock 

 was accompanied by a loud report, like the discharge of a cannon ; people 

 mistook it for the sigual guu of the mail steamer. This was felt at Monterey, 

 and in Contra Costa County. 

 May 2d, Oh. 10m. — A severe shock was felt at Los Angeles. It caused much 

 trembling among the buildings, and considerable alarm among the people, 

 many leaving their beds. The shock was preceded by two loud reports like 

 the blasting of rock ; it apparently came from the north-west ; no damage was 

 done. 

 August 2d, 5k. 20m. — A light shock was felt in San Francisco. It was suffi- 

 ciently strong to awaken persons in bed ; it was evidently more severe in 

 Stockton. 

 August 27th, 21h. 15m. — An earthquake was felt at Mission San Juan, Mon- 

 terey County. There were two distinct shocks with short intervals elapsing, 

 the second being the heaviest. The motion is described as undulatory and 

 coming from the west. It was felt at Monterey and at Santa Cruz. 

 September 6th, 3h. — A smart shock felt at Santa Cruz. It created considera- 

 ble consternation and many persons left their beds. 

 September 20th, 23h. 30m. — A very severe shock was felt in different parts of San 

 Diego County, and at that town. At Santa Isabel the ceilings of the dwell- 

 ings were shaken down ; the cattle stampeded and ran bellowing in all direc- 

 tions, and the Indians seemed equally terrified. The walls of the adobe build- 

 ings were many of them cracked. The motion is described as oscillatory. A 

 light shock occurred on the following Monday morning. 

 November 12th, 4h. — A smart shock occurred at Humboldt Bay. Another 

 shock was reported but no date given. 



From the record before us it will be seen that of fifteen, the total number 

 of earthquakes recorded during 1856, seven have been felt in San Francisco in 

 common with other parts of the State ; seven have occurred south of this local- 

 ity that were not observed here, and four north of it. Of the seven shocks 

 noticed here five only were not observed in any adjacent district, and may be 

 considered as strictly local. The periods of the year at which the shocks have 

 occurred, are as follows : During the winter months, five ; during the autumn, 

 three ; during the spring and summer, six. None have taken place between the 

 vernal and autumnal equinoxes. 



We have records of considerable and violent volcanic phenomena throughout 

 the northern seas, and islands both to the east and west of Alaska. The Rus- 

 sian frigate Dwina, while lying at Shuam Shu, brings intelligence of the out- 

 burst of a volcano in that vicinity about the twenty-second of June, and on 

 the twenty-fifth of the same month passed through fields of floating pumice ; 

 the latitude by observation being fifty degrees fifty-three minutes, and longitude 

 one hundred and fifty-eight degrees thirty-two minutes east, per chronometer. 



