Oct. 25, 1915 
Temperature and Capillary Moisture in Soils 
165 
abstracting force. When the attractive forces of the soil for water are 
satisfied and the thickness of the surface and capillary films is increased, 
then greater quantities of water will be removed by the same abstracting 
force. The smaller thermal water movement which occurs in the moist 
and dry soil rather than in the soil of uniform moisture content is due 
mainly to the cheesecloth which is placed between the dry and moist 
CLKDE S/LT LOAM 
EXPL/Wnr/OA/: 
—— Water moved from mo/st so//at 40 *c, to dry so// at 0*c. 
••••••• >* » » » « t* C°C. ” ** ** 40°c- 
» » >* Jt *» 20 °c. » ** ** » 0°c. 
« n ** t> » 9 » 0 °C. *> ** *> »> 20 *c. 
Fig. 9. “Curve showing the percentage of moisture moved from a moist and warm column to a dry and cold 
column of Clyde silt loam, and from a moist and cold to a dry and warm column of Clyde silt loam. 
columns of soil. Although this cheesecloth was very thin and had wide 
meshes, yet it prevented the two columns from forming a complete and 
perfect contact; consequently the dry soil had to absorb water directly 
through the cheesecloth as well as from the soil. 
Another factor which would seem to impede the rate of water move¬ 
ment from a moist and warm to a dry and cold column of soil is the 
resistance which the dry soils offer to wetting, owing to the air film 
