542 
HERBERT C. HANSON 
Results 
On July II, 1916, four sets of branches were arranged on a Fraxinus 
pemisylvanica growing isolated in a pasture. The tree had a well- 
shaped, fairly dense crown. One potometer containing south periph- 
ery leaves and one containing center leaves were placed among . the 
leaves at the south periphery about 10 feet above the ground. Two 
more potometers, one containing south periphery leaves, the other 
center leaves, were placed within the crown at about the same height 
as the other two potometers. There was very little wind and the sky 
was very hazy. The transpirations for periods of 15 minutes and for a 
total of three hours are given in the following table : 
Table 2 
Transpiration of Fraxinus Pennsylvanica on July 11, igi6 
Total 
Loss per 
Total 
Loss per 
Time 
Loss in 
Sq. Dcm. 
Time 
Loss in 
Sq. Dcm. 
P.M. 
Cc. 
in Cc. 
P.M. 
Cc. 
in Cc. 
1:08 
1:23 
1:23 
0.5 
0.0212 
1:38 
O.IO 
0.0054 
1:38 
0.9 
•0383 
1:53 
.20 
.0110 
1:53 
1.2 
.0512 
2:08 
.20 
.0110 
2:08 
1-3 
•0554 
2:23 
•35 
.0194 
Leaves from 
2:23 
145 
.0617 
Leaves from 
2:38 
•35 
.0194 
south periphery 
2:38 
145 
.0617 
center of crown 
2:53 
•35 
.0194 
placed at south 
2:53 
1.4 
.0596 
placed at south 
3:08 
•30 
.0166 
peripher}' 
3:08 
145 
.0617 
periphery 
3:23 
•35 
.0194 
3:23 
145 
.0617 
3:38 
•55 
.0304 
3:38 
1-35 
•0574 
3:53 
•45 
.0248 
3:53 
1-3 
•0554 
4.08 
•35 
.0194 
4:08 
1. 15 
.0488 
Total 
3 hrs 
14.90 
•634 
2 f< hr 
3-55 
0.1962 
1.08 
1:23 
45 
0.0175 
1:23 
1:38 
•55 
.0216 
1:38 
0.20 
0.0087 
1:53 
.65 
.0254 
I ••53 
•25 
.0110 
2:08 
•75 
.0293 
2:08 
.25 
.0110 
Leaves from 
2:23 
.80 
•0313 
Leaves from 
2:23 
•35 
•0155 
south periphery 
2:38 
.90 
•0352 
center of crown 
2:38 
.30 
.0132 
placed at center 
2:53 
•95 
.0372 
placed at center 
2:53 
.40 
.0177 
of crown 
3:08 
I. GO 
.0392 
3.08 
.40 
.0177 
3:23 
1.05 
.0411 
3 ••23 
.40 
.0177 
3:38 
1. 10 
.0431 
3:38 
.40 
.0177 
3:53 
0.90 
•0352 
3:53 
•35 
•0155 
4:08 
0.90 
•0352 
4:08 
•35 
•0155 
Total 
3 hrs 
10.00 
•3913 
2^ hr 
3^65 
.1612 
