352 



[Jur>e20. 



Philadelphia; the Societies at Copenhagen, Harlem, G6t- 

 tingen, Gorlitz, Freiburg, Stuttgard, Liege, Lyons, Bor- 

 deaux and Salem; the Observatories at St. Petersburg, 

 Munich, Paris, Greenwich and Capo Town; the University 

 at Christiania; the Statistical Commission of Belgium; the 

 Anthropological Society and Geological Institute at Vienna; 

 the German Geological Society and Botanical Association, 

 at Berlin; the Zoological Garden, at Frankfurt; the Geo- 

 graphical, Anthropological and Antiquarian Societies, Eth- 

 nographical Institution and Museum of Natural History, at 

 Paris; the Physical, Linnaean and Geographical Societies, at 

 Bordeaux; the British Association; the Astronomical, Me- 

 teorological, Geographical, Geological and Zoological Socie- 

 ties, Victoria Institute and London Nature; Mr. L. C. Miall, 

 of Leeds; T. P. James, of Cambridge, Massachusetts; Mrs. 

 Pickering, of Boston ; the Cambridge Library and Museum 

 of Comparative Zoology; Prof. J. D. Whitney, Prof. W. A. 

 Norton and Silliman's Journal, of New Haven; the Brooklyn 

 Entomological Society ; the American Chemical Society and 

 Mr. F. R. Rathbun, of New York; the Franklin Institute, 

 Zoological Society, Medical News, American Journal of 

 Pharmacy and International Committee of Philadelphia; the 

 American Journal of Mathematics, at Baltimore; U. S. 

 Smithsonian Institution and Win, B. Taylor, of Washing- 

 ton ; the Wisconsin Natural History Society; the Geo- 

 graphical Society and National Museum in Mexico. 



A medal of Joseph Henry, was received from the en- 

 gravers of the Mint, Messrs. Wm. and Chas. E. Barber, for 

 which, on motion, the thanks of the Society were presented 

 to the donors. 



Mr. Henry Phillips, Jr., offered for the acceptance of the 

 Society, under certain conditions, a copy of Sabin's Biblio- 

 theca Americana, as far as published, which, on motion, was 

 accepted for the Library. 



No. 103 of the Proceedings, just issued, was laid upon the 

 table for examination. 



A simple and closely approximate diagrammatic solution 



