286 



et Cliaussees in Paris ; from the Liuuean Society, dated 

 LoikIou, Aug. 18tli ; from the Meteorological Office, dated 

 London, Aug. 1876 ; from the Secretary of the State of Il- 

 linois ; and from the Davenport (Iowa) Academy of Natural 

 Sciences, Sept. 15th, desiring complete sets of Transactions 

 and Proceedings. 



A letter was received from Mr. 0. A. Kesselmeyer, 1 Peter 

 Street, Manchester, England, presenting a copy of his Card 

 Calendarium. 



Donations for the Lihrary were received from the R. Bel- 

 gian Academy ; French Ministiy of Public Works ; Annales 

 des Mines ; Nature ; Linnean Society ; Society of Antiqua- 

 ries; R. Geological Society of Ireland; Sillimanaud Dana; 

 Editors of the American Library Journal and Medical News ; 

 Buflalo Society of Natural Sciences; and the Davenport 

 Academy of Natural Sciences. 



Professor Houston made an exhibition of a new tele- 

 graphic machine called a " Pneumo-dynamic Relay Sounder,*' 

 where the local battery is replaced by compressed fluid, and 

 explained it by a working model and diagram. Attached to 

 the armature is a bent lever, with a valve mechanism open- 

 ing and closing a conduit leading from a reservoir of con- 

 densed air. The issuing air swells out a diaphragm of rub- 

 ber cloth covering a space of one sixty-fourth of an inch, 

 and moves a disc, which moves the striking lever, the return 

 stroke being efi:ected by a spring. The balance of the valve 

 is so adjusted as to diminish for opening the valve. This is 

 aftected by an accessory diaphragm pressing upon the other 

 arm of the bent lever; the tension is then equal to the ad- 

 justed difference. The instrument works with rapidity 

 enough to get responses easily to thirty-six beats per second. 



Pending nominations Nos. 804, 805, 806, 807, and new 

 nomination No. 808, were read. 



On motion of Mr. Gabb, the committee on Dr. Valentino's 

 paper was requested to report at the next meeting. 



And the ineeting was adjourned. 



