June, 1887.J elliott society. 137 



JUNE 23d, 1887. 



The President in the Chair. 



Book Received. 



California Academy of Sciences : Bulletin, Vol. II, No. 6. 



Dr. Manigault exhibited a specimen of the Seychelles Nut, Lo- 

 doicea Seychellaritm, from the Indian Ocean. 



The Chairman concluded the reading of his observations upon 

 the Earthquake. "^ 



JULY 28th, 1887. 



The President in the Chair. 



Dr. Maxigault continued his verbal remarks on the effects upon buildings 

 of the earthqualie shock of August 31, 1886. 



Having restated his belief that all the damage done by that shock was pro- 

 duced by wave movements, he said that it was important to explain that only 

 those houses, both of brick and of wood, which had more height than either 

 width or length, could rock in a decided manner while the earth waves were 

 passing underneath. 



Such a building as the Msmminger School, which, in its central portion un- 

 der the dome, has more height than leng-th of base, is a good illustration of 

 this statement. For, on a certain day early in Xovember. 1886, between the 

 hours of 12 noon, and 1 p. m., while he was standing on the highest floor, a 

 wave movemant commsnced which lasted over 3^ seconds. It was slight in 

 degree, bat the waves folio ,ved each other with extreme regularit}'^, and the di- 

 rection of their coming was without doabt from the West. After a few con- 

 fused movements, dtiring which the inert mass of masonry was being set in 

 motion, the entire building swayed from West to East, probably not more than 



* Referred to the Commission appointed Sept 23d, 1S86. 



VOL. n. 18 PublishodSep., ISST. 



