37 
Ordinary Meeting, November 29th, 1864. 
R. Angus Smith, Ph.D., F.R.S., &c., President, in 
the Chair. 
Mr. E. C. Buxton was elected an Ordinary Member of the 
Society. 
Dr. Joule exhibited a magnetic needle for showing rapid 
and minute alterations of declination. It consisted of a piece 
of hardened and polished watch spring, an inch long and 
one-tenth of an inch broad, suspended vertically by a filament 
of silk. The steel was magnetised in the direction of its 
breadth. He remarked that Professor Thomson had long 
insisted upon the advantages which would attend the use of 
very small bars in most magnetical investigations, and had 
employed excessively minute needles in his galvanometers 
with great success. Dr. Joule stated his intention to fit up 
his needle so as to be observed by light reflected from its 
polished surface, or otherwise by viewing a glass pointer, 
attached to the bottom of the steel, through a microscope. 
He believed that by the latter plan he should be able to 
observe deflections as small as 1" of arc. 
Pboceedinos— Lit. & Phil, Society— Vol. IV— No, 5— Session 1864-5. 
