EVAPORATION AND CAUSAL FACTORS. 



61 



A. Sunlight. 



B. Temperature. 



C. Saturation deficit. 



D. Wind velocity. 



E. Evaporation, 



blotting paper 

 atmometer. 



F. Evaporation, 



porous cup 

 atmometer. 



G. Absolute humidity. 

 H. Barometric pressure. 



I. Transpiration of 

 potted plant 



(Cow-beet) . 

 K. Transpiration of 

 cut leaves in 

 potometers 

 (Cow-beet) . 



L. Relative humidity. 

 M. Vapor pressure 



deficit. 

 N. Dew-point depression. 



67 8 9 10 11 MT. I 23-45 6 789 10 11 NOON 1 234-56 



FIG. 32. Series*33, showing evaporation, transpiration, and the factors concerned 



for September 8-9, 1919. 



