EVAPORATION AND PLANT HABITATS. 5 



TABLE II. 



Week ending. Sunshine. Shade. Ratio. 



July 29 211 64 3.2 



August 5 194 75 2.6 



August 12 203 50 4.0 



August 19 163 65 2.5 



August 26 140 42 3.3 



September 2 195 77 2.5 



September 9 160* 72* 2.2* 



September 16 160* 72* 2.2* 



September 23 198 104 1.8 



September 30 180 115 1.6 



October 7 114 80 1.4 



October 14 160 100 1.6 



On June loth two atmometers were installed at Columbia, 

 Mo., one in a strawberry patch in the open and the other in 

 a shade tent also in the midst of strawberry vines. Readings 

 were taken at approximately weekly intervals until October 9, 

 when the experiment was discontinued on account of frost. 

 For operating these instruments I am indebted to the co- 

 operation of Dr. B. M. Duggar, through whose kindness 

 these comparative data are here presented. The rates are 

 given in Table III, which also Includes the ratios of the rates 

 in sunshine to those in shade. The coefficients of correction 

 for these two cups were 0.992 for the one in sunshine, and 

 0.995 for the one in shade, that is, the observed loss is to be 

 multiplied by the proper coefficient to produce the quantity 

 which would have been lost from the standard cup, had it 

 been used in place of the one actually in operation. As has 

 been stated in the article on Evaporation and Development, 

 cofficients which vary from unity by an amount less than 0.0 1 

 are neglected. Therefore the rates given in Table III are 

 those actually observ^ed. 



•Calculated from a period of two weeks. 



