THE TEMPERATURE OF LEAVES OF PINUS IN WINTER 63 
Table XIV i 
March 10, 1914 
Clear. Breeze light. Relative humidity 76% 
Detached branch partially protected against air currents by cheese cloth screen. 
I 
3 
4 
= 1 
6 1 
8 
Time of 
Obser- 
vation 
No. of 
Obser- 
vations 
Aver. 
Bridge 
Reading 
Calculated 
Temp. 
Difif. 
Shade 
Temp. 
Black Bulb 
in Vacuum 
Diflf. 
Columns 
5 and 6 
Actual 
Leaf 
Temp. 
10.45 
10.46 
10.47 
10.48 
10.49 
10.50 
64.0 
50.5 
63.8 
73-0 
85.8 
82.0 
75-0 
7.69° 
6.07 
7.67 
8.77 
TO.3I 
9.86 
9.02 
> 2.0° 
32.2° 
30.2° 
9.69° 
8.07 
9.67 
10.77 
12.31 
11.86 
11.02 
11.47 
11.48 
11.50 
II. 51 
\ 
J 
74.0 
71-5 
61 .0 
77.0 
74.2 
79-4 
79-4 
73- 0 
74- 4 
8.83 
8.53 
7.28 
9.17 
8.85 
9-47 
9-47 
8.71 
8.88 
- 4.2 
35-0 
30.8 
13-03 
12.73 
1 1 .48 
13-37 
13-05 
13.67 
13.67 
12.91 
13.08 
12.40 
12.41 
12.42 
12.43 
12.44 
12.45 
\ 
75-5 
80.0 
63.5 
66.0 
71-5 
69.5 
76.4 
65.0 
75-0 
61.8 
76.5 
8.98 
9-52 
7-56 
7-85 
8.51 
8.27 
9.09 
7-73 
8.93 
7-35 
9.10 
> 5-5 
36.7 
31.2 
14.48 
15.02 
13.06 
13-35 
14.01 
13- 77 
14- 59 
13- 23 
14- 43 
12.85 
14.60 
12.54 
12.55 
82.0 
85.2 
9.76 
10.12 
} 5.5 
36.7 
31.2 
15.26 
15.62 
1.05 
1.06 
1.07 
83.0 
64-5 
79-5 
72.5 
9.88 
7.68 
9.46 
8.63 
1 5.50 
35.0 
30.0 
14.88 
12.68 
14.46 
13.63 
Average 
8.91 
4.44 
13-35 
(6) The Temperature of Leaves at Different Angles to the Sun's 
Rays. — Finally an experiment was made to determine the difference 
in temperature between two leaves at different angles to the sun's 
