Oct. 4. i9i5“Mar. 27,1916 
Illustrations 
XXI 
Page 
Fig. 2. A portion of the same section of a potato plant shown in figure 1, show¬ 
ing the mycelium in the pith region of the stem. 90 
3. A cross section of the cortical region of a potato stem, showing the 
mycelium of Phytophthora infestans . 91 
An Automatic Transpiration Sc alb op Earge Capacity for Use with 
Freely Exposed Plants 
Fig. i. Vesque’s automatic balance for measuring transpiration. 118 
2. Anderson’s apparatus for measuring transpiration. 118 
3. Ganong’s automatic transpirometer. 119 
4. Woods’s adaptation of Marvin’s weighing rain gage as a transpiration 
balance. 120 
5. The Marvin register used by Woods for recording transpiration. 120 
6. Schematic diagram of Blackman and Paine’s recording transpirometer 121 
7. Krutizky’s potometer for recording transpiration.. 121 
8. The transpiration balance of Richard Fr£res with its recording appara¬ 
tus. 122 
9. Copeland’s apparatus for recording transpiration. 123 
10. Corbett’s apparatus for measuring transpiration. 124 
11. View of the beam and auxiliary equipment of the platform transpira¬ 
tion scale designed to carry large pots of plants weighing 150 kgm. 
or more. 125 
12. Details of the ball-dropping mechanism. 126 
13. Dashpot for preventing the oscillation of the beam dining windy 
weather. 127 
14. Spring motor, showing the cam K for raising the beam, and the fan F 
for regulating the speed. 127 
15. Another view of the spring motor, showing the control mechanism. .. 128 
16. Sample‘records from the automatic transpiration scale. 129 
17. Wiring diagram of the electric circuits of the automatic transpiration 
scale. 130 
18. Transpiration graphs corresponding to the three records given in figure 
16, plotted in rectangular coordinates. 131 
Effect of Temperature on Movement of Water Vapor and Capillary 
Moisture in Soils 
Fig. i. Apparatus for determining thermal translocation of soil moisture when 
the column of soil lay horizontally. 142 
2. Apparatus for determining thermal translocation of soil moisture when 
the column of soil stood vertically. 143 
3. Curve showing the movement of moisture from a warm to a cold col¬ 
umn of soil of uniform moisture content. 146 
4. Diagram illustrating the cause and mechanism of moisture movement 
from a warm to a cold column of soil of uniform moisture content... 151 
5. Curve showing the percentage of moisture moved from a moist and 
warm column to a dry and cold column of quartz sand, and from a 
moist and cold to a dry and warm column of quartz sand. 162 
6. Curve showing the percentage of moisture moved from a moist and 
warm column to a dry and cold column of Miami sandy loam, and 
from a moist and cold to a dry and warm column of Miami sandy 
loam. 162 
7. Curve showing the percentage of moisture moved from a moist and 
warm column to a dry and cold column of heavy sandy loam, and 
from a moist and cold to a dry and warm column of heavy sandy 
loam. 163 
