9 8 



VICTOR E. SHELFORD. 



out these relations in a rough way. More accurate results were 

 not easily obtainable because of the difficulty of controlling 

 humidity and temperature and accurately measuring the flows. 

 It will be noted that a doubling of velocity was accompanied by a 

 doubling of evaporation only in the cases of .052 and .104 meter 

 per second. A breeze of .208 meter per second can be distin- 

 guished by the skin of the hand but usually lesser flows cannot. 



TABLE III. 



Showing the relation of evaporation to the rate of flow and to relative humidity 

 under the experimental conditions, together with the relative rate of increase of 

 evaporation and velocity. (0.52 meter per sec. equals i.i miles per hour, 0.68 

 equals 1.5; o.io equals 0.2.) The equipment is not accurate enough to make this 

 more than a general guide. Pressure was not read. 



Compare with Schierbeck ('95), p. 221. Changes in rate of flow give greater 

 difference in evaporation below .208 meter per sec. than above. Schierbeck's 

 table gives accurate data from .88 m. per sec. to 4.23 m. per sec. for exposed water 

 surfaces (see Livingston, G. T., '08, '09). 



(a) Physiological Effect and Reactions. 



The same species were studied and the same general physio- 

 logical effects noted as where the difference in evaporation was 

 due to dryness. Only slight evidence of mechanical stimulation 

 occurred in the case of Fontaria in the gradient. The sala- 

 manders showed the same kind of activity and symptoms of 

 drying in the rapid as in the dry air. The animals pushed 



