217 



tubular arms, slightly inclined to one another, are attached 

 to this plate ; and their other extremities are connected by a 

 cross-piece, which carries a short scale at a distance of 

 eighteen inches from the mirror. This part of the apparatus 

 is employed in determining the total angles of deflection. 



The soft iron bar is a cylinder, twelve inches long, and 

 three-fourths of an inch in diameter. One of its extremities 

 is enclosed in a hollow cylinder of brass, connected with a 

 horizontal pivot which revolves in a fixed socket. The axis 

 of this pivot being in the line passing through the centre of 

 the suspended magnet, and perpendicular to the magnetic 

 meridian, it is obvious that the bar has a movement of rota- 

 tion in the plane of the magnetic meridian itself. The dis- 

 tance of the axis of the bar from the centre of the magnet is 

 about five inches; and it is so placed that the induced pole 

 is in the direction of the axis of the pivot, and thus remains 

 fixed during the movement of the bar. 



The changes of position of the suspended magnet are 

 observed at a distance by means of a fixed telescope and 

 scale. The scale, whose divisions are reflected by the mir- 

 ror, is attached above the telescope to the support near the 

 eye-end. 



Dr. Fulton made some observations on Grecian and Ro- 

 man Architecture. 



February 14. 



SIR Wm. R. HAMILTON, LL.D., President, in the Chair. 



Captain Stirling, 73rd Regt.,Rev.Thomas Stack, F.T.C.D., 

 Joseph Nelson, Esq., Q.C., and Rev. Robert Chatto, were 

 elected members of the Academy. 



Dr. Anster read a paper, by the Rev. J. Wills, upon 

 Mr. Stewart's attempt to explain certain processes of the 



