DISTANCE FROM LAKE ELEVATION ABOVE LAKE 



a 10 feet 3 feet 



b 190 feet 10 feet 



c 985 feet 30 feet 



d 1785 feet 75 feet 



For illustration the observations of July 26th, 1913, are taken. 

 The wind was from the southwest and varied in velocity from 

 10 to 15 miles per hour during the period of observations which 

 continued from 7 a. m. until 3 :30 p. M.^ 



The relative humidity and evaporation are given in the fol- 

 lowing tables: 



RELATIVE HUMIDITY 



Time Station a Station h Station c Station d 



7:00 A. M. .86 .78 .82 .78 



9:00 A. M. .73 .62 .65 .58 



10:00 A. M. .65 .60 .41 .58 



11:00 A. M. .60 .53 .54 .51 



12:30 P. M. .55 .51 .43 .49 



2:00 p. M. .62 .48 .42 .48 



3:30 P. M. .64 .49 .48 .54 



EVAPORATION 



Piche 3.85 2.57 3.21 3.29 



Pan 94.20 cc. 63.30 cc. 87.25 cc. 93.00 cc. 



It will be noticed that the relative humidity was much the 

 same at the several stations and that at station a, nearest the 

 lake, it was not much greater than at the more remote stations. 

 It is also noteworthy that evaporation was slightly greatest near- 

 est to the lake, probably because the exposure to wind was a little 

 greater. Station h, just at the base of the steeper slope, shows 

 the least evaporation. It was also most sheltered by its imme- 

 diate surroundings. The temperature varied from 71° to 89° 

 Fahrenheit at station a and from 73° to 91° F. at station d. 



Unfortunately observations could not be made on the same 

 day on the south side of the lake, but 16 days earlier, July 10th, 

 silimar observations were made on Twin Mounds between the 

 hours of 7 A. M. and 3 p. m. The wind was from the south with 



6 For the evaporation observations the Piche evaporimeter, and open pans 150 

 mm. in diameter were used. The Piche unit is a tenth of a cubic inch, and the pan 

 unit is a cubic centimeter. 



18 



