33 



the principle, still the vibrations were curious, and as interesting as 

 any other of the many vibrations produced by heat or galvanism. 



The vibrations are caused by the alternate actions of the heat of 

 the lamp, bending the bar away from its influence, and of the conse- 

 quent rapid cooling, which straightens it, throwing it back again within 

 the former influence, this vibrating motion being assisted by the elas- 

 ticity of the bar. Its approach to a red-hot bar or ball of iron pro- 

 duces the same effect. The vibrations do not take place when the 

 platinum side of the spring is turned towards the source of heat, or 

 when the action on the silver side is made perfectly uniform, as by 

 brinjring it under the influence of a thick red-hot iron bar bent in the 

 shape of the cuuve, which it assumes by the heat received from it, or 

 if heated by a very steady column of hot air striking, as before, 

 against its silver side, but placed in such a position that the bending 

 of it does not throw it out of the influence of the heating current. 



Judge Kane made a verbal report from the committee ap- 

 pointed in Februarys last, upon the subject of providing more 

 extended and convenient accommodations for the Library of 

 the Society, and moved that an appropriation of ^2000 be 

 placed at the disposal of the committee, and that they be au- 

 thorized to expend such amount, not exceeding that sum, as 

 may be necessary for the object of their appointment: — Which 

 motion was agreed to and the appropriation made by the So- 

 ciety. 



Stated Meeting, May 19. 



Present, nine members. 



Dr. Franklin Bache, President, in the Chair. 



A letter was read from the Corresponding Secretary of the 

 Wisconsin Historical Society, dated Madison, Wisconsin, 

 May 10, 1854, soliciting an exchange of publications with this 

 Society. 



The following donations were announced : — 



FOR THE LIBRARY. 



Quarterly Journal of the Chemical Society. No. XXV". Vol. VII. 1. 

 April, 1854. London. 8vo. — From the Society, 



VOL. VI. — E 



