THE EFFECT OF SLOPE EXPOSURE. 



Table II. — Evaporation. 



218 



3. Air Temperature. This was measured by ordinary mercury 

 thermometers, a battery of three thermometers being used at each 

 station. In the accompanying table the readings of each thermo- 

 meter are recorded and also the average of the three. 



Table III. — Air Temperatures. 



The air temperature is therefore greater on the northern 

 slope throughout the day, but the difference is a comparatively 

 small one. The maximum temperature attained on the southern 

 slope is 23"25°C., that on the northern 26'6°C., a difference of 

 only 3"35°C. As in the case of the other factors measured, the 

 difference reaches its maximum in the afternoon at about 3 p.m. 



4. Soil Temperature. Three thermometers were inserted into 

 the soil at each station to a depth of about 2 in. and were read 

 at hourly intervals. The readings are given as in the case of the 

 air temperatures. 



