(381) 
ON SOME METEOEOLOGICAL CONDITIONS CONTKOLLING 
NOCTUENAL EADIATION.- 
By J. E. Sutton, Sg.D., Hon. Memb. E.Met.S., F.E.S.S.Af. 
(Eead March 20, 1912.) 
Some observations made at Kimberley during a period of eight years 
with two radiation (spirit) thermometers, one placed upon the grass and 
the other mounted on a light brass stand 5 inches above the grass, gave 
the following monthly averages of minimum temperature : — 
TABLE 1. 
Minimum Eadiation Tempeeatuees. 
5 Inches above Grass, 
On Grass. 
D. 
58-0 E. 
55-0 F. 
3°0 F. 
Feb 
57-1 
53-9 
3-2 
Mar 
53-6 
50-9 
2-7 
April 
45-0 
415 
3-5 
May 
37-5 
32-8 
4-7 
June 
31-2 
25-5 
5-7 
July 
30-6 
24-2 
6-4 
Aug 
32-9 
26-9 
60 
Sept 
41-6 
36-5 
51 
Oct 
45-5 
40-9 
4-6 
Nov 
50-2 
46-1 
4-1 
Dec 
551 
51-8 
3-3 
Year 
44-9 
40-5 
4-4 
* This paper should be read in conjunction with a previous paper : J. R. Sutton, " The 
Influence of Water Vapour upon Nocturnal Radiation," in Scientific Proc. R.D.S., 
August, 1905. 
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