344 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



On motion of Mr. Adriance, tlie Association adjourned to the secoasl 

 Thursday of September next, at 7| o'clock p. m. 



American Institute PoLYTEcnNic Association, ) 

 Thursday evening, Sept. Sth, 1864. ) 



Prof. S. D. Tillman in the chair; Benjamin Garvey, Secretary, 



Miscellaneous BusinesSc 



Mr. J. Bull exhibited a series of photographic Views of prominent places 

 in Central Citj^, Colorado Territory, made by Mr. Henry Garbanati, of that 

 place, and presented to the American In-titnte. These views give ns a 

 better idea of that city than could be obtained from any written descrip- 

 tion. Mr. B. alluded to other gifts from Mr. Garbanati, and to his letters, 

 which describe in glowing terms the mineral richness of the conntry and 

 its future prospects. 



Dr. Rowell exhibited a curiosity in the shape of what miglit be called a 

 bogus California nugget. It was an artificial composition well calculated 

 to deceive. It had formerly a place in the office of a dealer in mining 

 stocks. 



The following items of scientifie news were then read and elucidated by 

 the Chairman: 



Improvement of the Daniel Battery. 



Father Secchi advises the use of fine sand or powdered sulphur in the 

 porous cell; its constancy is thus increased by preventing the liability to 

 local action taking place on the zinc. When large porous cells cannot be 

 easily obtained, he proposes as a substitute bags made of coarse linen 

 cloth well anointed with a luting of flour and lime. 



A Mineral Containing Cgesium. 



M. Pisani has discovered that the Elban mineral Pollux contains about 

 34 per cent, of the new metal Ccesium, It was previously supposed to 

 contain either potassium or sodium. 



New Chromic Salt. 



M. E. Kopp announces the discovery of the double chromate of potash 

 and ammonia, which promises, from the facility with which it is decom- 

 posed by light, to be of service in photography. 



Improvement of Mining Powder. 



M. Nobel says, by damping mining powder with nitroglycerin its explo- 

 sive power is trebled, and the noise of explos^ion is much less tlian when 

 ordinary powder is used. 



