332 [April. 



duced to uniform temperature (32° Fahr.), and the monthly means 

 found, by ofl&cers of the Government survey of the lakes, as follows : 



J- F. M. A. M. J. J. A. S. 0. N. D. Mean. 



29.385 .368 .307 .334 .300 .356 .356 .352 .386 .372 .338 .403 .355. 



Projecting a curve with these figures, and drawing a line bisect- 

 ing the slopes of the several undulations (to represent the earth's 

 orbit), you will find a tide with four maxima and four minima cor- 

 responding very nearly with the cardinal points of the ellipse." 



ITominations Nos. 568 to 572 were read. 

 And the Society was adjourned. 



Stated Meeting, April 5, 1867. 



Present, sixteen members. 



Dr. Wood, President, in the Chair. 



Letters were read from the Geological Bureau of Sweden, 

 dated November 1, 1866 ; from the Royal Society of Sci- 

 ences at Upsal, 1st October, 1866 ; from the Royal Acad- 

 emy of Naturalists at Vienna, October 30, 1866, severally an- 

 nouncing donations to the Library ; also from the Nicolai 

 Observatory at Pulkowa, June 12, 1866 ; from the Royal 

 Society of Sciences at Upsal, September 15, 1866 ; from 

 Royal Asiatic Society, London, December 17, 1866 ; from 

 the Boston Society of Natural History, March 25, 1867 ; and 

 from the Smithsonian Institution, Washington, February 20, 

 1867, severally acknowledging the receipt of publications of 

 this Society. 



Donations for the Library were announced, viz. : From the 

 Imperial Rjissian Geographical Society ; from the Nicolai 

 Observatory at Pulkowa ; from the Bureau of Geological Re- 

 search of Sweden; from the Imperial Society of Naturalists 

 at Moscow ; from the Royal Society of Sciences at Upsal ; 

 from the Royal Academy of Sciences at Vienna ; from the 



