35 
Ordinary Meeting, November 26th, 1867. 
Edward Schunck, Ph.D., F.R.S., &c., President, in the 
Chair. 
Mr. James Stanley Kipping was elected an Ordinary 
Member of the Society. 
“On a Thermometer unaffected by Radiation,” by Dr. 
J. P. Joule, F.R.S., &c. 
In the annexed figure a is a copper tube 
about one foot long, and has a tube open at 
both ends in the centre. Water is poured 
into the space between the two tubes. In 
the centre tube there is a spiral of fine wire 
suspended by a filament of silk, and having 
a mirror at m. There is a lid at p which 
can be removed at pleasure from the lower 
end of the tube. When p is situated as in 
the figure, there can be no draught, and con- 
sequently the spiral with its mirror is at 
zero of the scale. But when p is re- 
moved, there is a current of air which turns 
the spiral, if the air in the tube has a dif- 
ferent temperature from that of the outside 
atmosphere. In my apparatus, one degree ' 
Fah. produces an entire twist of the filament. I find that the 
temperature in the tube is generally warmer than in the out- 
side atmosphere of a room, which must be owing to the con- 
version of light and other radiations into heat on coming into 
contact with the copper tube. I have tried the apparatus in 
the open air on a still day, with the same result. Of course 
Proceedings — Lit. & Phil. Society — Vol. VII. — No. 4 . — Session, 1867-8. 
