338 



EDITH BELLAMY SHREVE 



TABLE 8— Continued 



TIME 



MAXIMUM 



ERROR FOR 



A 



WATER-CONTENT 



Gain 



LOS3 



Plant No. 32 — Continued 



June 25, 5 a.m. 



June 25, 9 a.m. 



June 25, 5 p.m.. 

 June 25, 11 p.m. 

 June 26, 5 a.m.. 

 June 26, 7 a.m.. 



grams 



4.5 



3.2 



10.2 

 3.6 

 7.3 

 2.5 



grams 



2.0 



6.1 



9.6 

 2.8 

 4.9 

 2.5 



grams 



0.0 



2.9 



0.0 

 0.0 

 0.0 

 0.0 



grams 



2.5 



0.0 



0.6 

 0.8 

 2.4 

 0.0 



riant No. 34 



June 20, 



June 21, 



June 21, 

 June 21, 

 June 21, 



June 22, 



June 22, 



June 22, 



June 23, 



June 23, 



June 23, 



8 p.m. 



8 a.m. 



12 m.. 

 4 p.m. 



9 p.m. 



8 a.m. 

 12 m.. 

 7 p.m. 

 7 a.m. 

 12 m.. 

 4 p.m. 



3.6 



1.2 

 0.9 



0.8 



5.5 

 0.9 

 1.2 



3.3 



2.0 

 0.5 

 1.0 



3.1 



1.8 



2.3 



(+0,1 



1-0.05 

 ± 0.2 



±0.1 



±0.1 

 f+0.4 

 1-0.7 



±0.2 

 f+0.4 

 \-0. 2 

 Condensation of water vapor on pots 



\ 



/ 



1 



0.0 



0.8 

 0.0 

 0.2 



0.0 



0.9 



1.1 



1.5 



0.8 



1.5 

 0.9 



f+0.3 

 -0.03 

 = 0.4 



0.0 



0.1 



0.3 



0.0 

 0.4 

 0.0 



2.4 



0.0 



0.0 



0.0 

 0.0 



in grams transferred from pot to aerial part of the plant during the night than at 

 8.29 a.m. the condition of equilibrium will be represented by the equation 



a - x (5.5) = a + x (15) + 3.5 (5.5) - 5.5 (15) 

 x = 3.1 



That is, transpiration was 2.5 grams greater than absorbtion. In the above cal- 

 culation the weight is in every case multiplied by its distance from the knife edge. 

 The maximum error for this plant was calculated by considering the estimated 

 center to be 5 cm. wrong first to the right and then to the left. Thus a total error 

 is calculated which allows for an error in the center of the transpiring parts 

 amounting to one-third of the length of the plant. 



A few minor changes were made in the form of the apparatus as described by 

 Briggs and Shantz. The apparatus used in the present work is shown in figure 9. 



