ACADEMY OF NATURAL SCIENCES. 239 



Regular Meeting, February 19th, 1866. 

 President in the chair. 



Nine members present. 



Dr. Colbert A. Canfield, of Monterey, was chosen a Correspond- 

 ing Member, and Dr. Henry Gibbons and Mr. Henry Janin, Resi- 

 dent Members. 



Donations to the Library : U. S. Census, 1860 — Agriculture ; 

 American Journal of Science, November, 1865, and January, 

 1866 ; Proceedings of the Phila. Acad. Nat. Sci., April to Octo- 

 ber, 1865 ; Theory of Parallels, by Matthew Ryan ; Description of 

 New Species of Pupidee, by E. S. Morse ; Proceedings of Boston 

 Nat. Hist, Soc, Vol. X, Sheet 2. 



The following paper was presented. 



Earthquakes in California during 1865. 



BY DR. JOHN B. TRASK. 



As in the preceding year we have "had much frequency in shocks of earth- 

 quake, with but trifling damage. 



January 9th, 7 h. — A smart shock at Santa Rosa, Sonoma County. 



January 19th, 8 h. 8 m. — A light shock at San Francisco. 



March 5th, 8 h. 45 m. — A light shock at Visalia, consisting of a tremulous 

 motion, succeeded by a roll or wave after an interval of about four seconds. 



March 7th, 23 h. — A smart shock at San Francisco. 



March 8th, 6 h. 22 m. — A smart shock at San Francisco. 



March 30th, 7 h. 28 m. — A very smart shock at San Francisco ; this was 

 felt at Oakland. 



April 15th, h. 40 m. — A severe shock occurred at San Diego, consisting 

 of three waves, following each other in quick succession ; the shock was pre- 

 ceded with a loud rushing sound. 



April 18th, 13 h. 31 m.— A light shock at San Francisco, and noticed at 

 Augel Island and Oakland. This shock was severe at San Juan (south), and 

 felt at precisely the same hour. 



April 27th, 15 h. 56 m.— A shock at San Francisco. 



May 24th, 3 h. 21 m. — A smart shock at San Francisco, consisting of a 

 single wave. At San Juan (south) the earthquake consisted of two sharp 

 shocks, and at Santa Cruz of one only. At the latter localities it was three 

 and four minutes later than at this city. 



September 22d (no hour). — A smart shock occurred at Treka. 



October 1st, 9 h. 15 m.— A very smart shock was felt at Fort Humboldt, 

 and throughout the district of Humboldt Bay. 



