94 



IOWA ACADEMY OF SCIENCE 



be seen in the record for June 29, July 1, 10, 11, 14, 16, 19, 

 20, 25. Effects of the wind in raising the level of the lake 

 at the laboratory may be seen in the record for July 9, 12, 16 

 and 28. The effect of large waves superimposed on the effects 

 of evaporation, precipitation and wind are to be noticed in the 

 tracing for June 29, 30, July 7, 12-14, 15 (very pronounced), 

 19, 20, 21, 22, 24-25, 27-28. 



THE TEMPERATURE OF THE LAKE. 



Three series of observations of the temperature of the lake 

 were obtained : one at the end of the pier at the laboratory 



Fig. 



-Apparatus used to ascertain the temperature of the water at 

 different depths. 



where the water was six and a half feet deep ; one, half way 

 between the pier and the spit and hook at the entrance to the 

 bay; and one close to the center of oscillation of the lake, as 



