2 9 ° 
Yapp. — -On Stratification in the Vegetation of a 
TABLE I. 
Date 
I 9°7 
Recorded at Wicken Fen. 
Recorded at Cambridge. 
Total 
in c.c 
of 2 
A 
evaport 
1 for pt 
4 hours 
B 
ztion 
zriods 
2 
C 
Maxiniu 
mum tern 
degrees 
A 
m and : 
per atm 
Centigf 
B 
mini- 
'es in 
■ade. 
C 
Wind 
direction , 
and 
velocity 
( estimated 
acc. to the 
Beaufort 
scale). 
Relative 
humidity. 
Rainfall 
in inches. 
Number 
of hours 
sunshine. 
Series 1 
July 10 
18.0 
3*15 
2-0 
max. 18*0 
min. 2.3 
18-0 
3 
14.6 
3*5 
N. 
1 
9 a.m., 89 
9 p.m., 92 
0.6 
o -75 
July 11 
70.4 
24.0 
5*45 
21.5 
2.0 
22-8 
19.0 
2.5 
S.W. 
1 
65 
94 
0 
! 2*75 
July 14 
40.1 
r 3*5 
2-45 
22.6 
5-9 
26.8 
21-2 
5-8 
N.W. 
0 to 1 
77 
88 
0 
0*5 
| ' 
Series 2 
Juiy 19 
54-5 
24-0 
6*95 
2 4*5 
2.8 
26.3 
2*5 
17.8 
3-6 
N.E. 
1 to 2 
76 
88 
0 
12.0 
July 21 
53*°5 
19-6 
7*5 
21-8 
6.2 
23*4 
5*7 
19.7 
6-5 
N.E. 
0 to 1 
80 
76 
0 
1-0 
Series 3 
Aug. 15 
86.5 
24*75 
2-0 
22.5 
10.5 
23*3 
ii *5 
16.7 
13.0 
S.W.byW. 
3 to 6 
67 
93 
0-08 
8-5 
Series 4 
Sept. 5 
49*55 
ii *35 
nil 
20*9 
8.0 
20-0 
17.4 
8*5 
S.W. 
2 to 3 
77 
78 
0*07 
1.63 
Sept. 7 
49*5 
13.0 
0.7 
25.2 
10.3 
24.9 
18.3 
9.2 
S.W. 
1 
74 
94 
0 
3*5 
Sept. 8 
66-7 
23*85 
4-75 
23.8 
ii *9 
23*4 
18. 1 
ii *7 
N.E. 
1 to 2 
85 
79 
0 
5*8 
After deducting a few occasions when one or other of the evaporimeters 
had to be removed for slight repairs, the time occupied by the first two 
series of experiments (in July, 1907) amounted to between seven and eight 
days. During this time the total evaporation from the different instruments 
was as follows : — 
A. 301.6 c.c. 
B. 11 3*35 c.c. 
C. 30.45 c.c. 
Taking A = 100, the relative evaporation in the three positions was 
according to the following ratios : — 
A : B : C = 100 : 37-6 : io-i. 
1 All the evaporation readings in this table have been corrected according to the method given 
in the Appendix (p. 39). 
2 On the following occasions the periods were not precisely 24 hours: — July 10th and 21st 
(23I hours each), and July nth (24^ hours). 
3 The B minimum thermometers were defective during Series 1 and 4. 
