METEOROLOGICAL OBSERVATIONS AT WISLEY, 1915. 131 
Jan Feb Mar Apr May Jun Jul Aug Sep OctNov Dec 
6G' 
50' 
40° 

Alsan 
Air 
Earth 
in. 
m. 
f / 
/ 
/ + 
/ 
/ 
1 
/; / 
, / 
/ 
/ 
/ 
\ 
/ It 
At 
\ 
■ \ 
. .V- 
/ 
60- 
50* 
40' 
Fig. 29. — Diagram showing Mean Temperature of Air, and of Earth 
at 1 Foot and at 4 Feet below the Surface at Wisley, for each 
Month in 191 5. 
Fig,; 3o 4 — Diagram showing the Relative Prevalence of Winds 
during 1915, the black circle representing calms, 
