ITI. 
THE INFLUENCE OF WATER-VAPOUR UPON NOCTURNAL 
RADIATION. 
By J. R. SUTTON, M.A., F.R.Mez.S. 
[COMMUNICATED BY PROF. J. JOLY, F.R.S., HON. SEC. ROYAL DUBLIN SOCIETY. | 
[Read, May 16; Received for Publication, May 19; 
Published, Aue. 19, 1905.] 
Ir has always seemed to me that Tyndall’s discovery of the 
absorption and radiation of heat by the vapour of water has been 
too hastily applied to meteorological problems. According to his 
experiments, the absorption of heat from any given source by 
ordinary atmospheric air containing aqueous vapour is propor- 
tional to the quantity of vapour present in a given space. He 
gave the following table :— 
Humip Arr. 
TENSION. | ABSORPTION. 
Inches. | Observed. Computed. 
5 16 | 16 
10 32 | 32 
15 49 48 
20 64 64 
25 82 80 
30 98 96 
“The third column here is calculated on the assumption that 
the absorption, within the limits of the experiment, is sensibly pro- 
portional to the quantity of matter in the tube. The agreement 
SCIENT. PROC. R.D.S. VOL. XI., NO. III. D 
