104 
PHYSICAL AND MATHEMATICAL SECTION. 
January 16th, 1883. 
Joseph Baxendell, F.R.A.S., President of the Section, in 
the Chair. 
Dr. J. P. Joule, F.R.S., exhibited and explained an arrange- 
ment for damping the small oscillations of a telescope. 
The figure represents the object glass end of a telescope 
armed with the leaden ring l. A circle of brass, r, girding 
the tube, carries hooks which hold the caoutchouc bands 
% i, i, thrown over the leaden ring. A similarly supported 
leaden ring is placed at the eyepiece end. I have applied 
rings weighing together 81bs. to a telescope tube weighing 
131bs. with the result that when wind was blowing the 
small oscillations were so far subdued that very satisfactory 
definition of the object was obtained, which without the 
rings would have been impossible. 
