leading to the hills north of the bay (see Plate I, fig. 

 2) ; station 3 was located in front of the Laboratory cot- 

 tage in a prairie opening (see Plate III, fig. 1) ; station 

 4 was in the small open bur-oak grove south of the cottage 

 (see Plate III, fig. 1) ; station 5 was on the bank near the steps 

 leading up from the Laboratory pier in a strip of prairie open- 

 ing leading down from the west and northwest (see Plate III, 

 fig. 2) ; station 6 was in the deep woods south of the Laboratory, 



and just north of the Beck spring. The elevation of station 5 

 was about 10 feet above the lake ; that of stations 3 and 4 about 

 30 feet ; of station 2 = 75 feet ; and station 1 = 152 f eet.^ The 

 locations of the stations are shown in figure 1. The obser- 

 vations were made on six consecutive days, August 6 to 11 in- 

 clusive, during the following periods : Aug. 6th, 9 a. m. to 7 p. 

 M. ; Aug. 7th, 8th, and 9th, 7 a. m. to 7 p. m. ; and Aug. 10th and 

 11th, 8 :30 A. M. to 7 :00 p. M. For the evaporation observations 

 open pans 150 mm. in diameter were used, and the loss was 

 measured in cubic centimeters. The general results are given 



* The last two elevations were furnished by Prof. A. O. Thomas. They were de- 

 termined July 26, 1910, when the elevation of the lake surface above sea-level was 



N 



1,230 feet. 



22 



