16 



BURTON EDWARD LIVINGSTON 



data have been corrected to the Li\dngston standard for this 

 instrument.'' 



In table 3 the ratio of relative transpiration by the white atmom- 

 eter, which absorbs comparatively little heat from the sunshine, 

 varies from 0.91 to 6.11 (1.0 to 6.7) and from 1.00 to 5.8g, for the 

 two plants, respectively. By the brown instrument, which sums 

 the effect of sunshine together with that of the evaporating power 

 of the air, these variations are from 0.89 to 5.66 (1.0 to 6.4) 



TABLE 3 



Transpiration, Phtsalis 



ABSOLUTE 



evaporation 



1 hour 



Plant 1 



Plant 2 



Plant 1 



Plant 2 



White 

 atmometer 



Brown 

 atmometer 



By white 

 atmometer 



By brown 

 atmometer 



By white 

 atmometer 



By brown 

 atmometer 



22 



1 



11 



1.47 



0 



91 



0 



89 



1 



20 



1 



18 



1 



22 



1.25 



23 



1 



U 



0.94 



1 



66 



1 



82 



1 



40 



1 



54 



0 



67 



0.61 



24 



1 



03 



1.15 



1 



07 



1 



06 



1 



20 



1 



19 



0 



96 



0.97 



1 



1 



00 



1.00 



1 



00 



1 



00 



1 



00 



1 



00 



1 



00 



1.00 





(0 



.35) 



(0.34) 



















(2 



03) 



(2.09) 



2 



1 



25 



1.24 



1 



47 



1 



51 



1 



46 



1 



49 



0 



85 



0.83 



3 



1 



03 



1.85 



2 



15 



2 



64 



1 



77 



2 



18 



0 



48 



0.39 



4 



0 



78 



1.03 



3 



54 



3 



12 



4 



68 



4 



12 



0 



22 



0.25 



5 



0 



97 



1.12 



2 



62 



2 



94 



3 



03 



3 



39 



0 



37 



0.33 



6 



2 



97 



3.59 



3 



81 



2 



88 



4 



60 



3 



49 



0 



78 



1.03 



7 



5 



83 



7.14 



3 



94 



3 



04 



4 



82 



3 



72 



1 



48 



1.92 



8 



7 



03 



6.76 



6 



11 



4 



95 



5 



88 



4 



76 



1 



15 



1.42 



9 



8 



39 



8.79 



5 



38 



4 



37 



5 



64 



4 



58 



1 



56 



1.92 



10 



8 



61 



8.29 



4 



39 



3 



60 



4 



23 



3 



47 



1 



96 



2.39 



11 



11 



88 



10.59 



4 



72 



4 



03 



4 



21 



3 



59 



2 



52 



2.95 



12 



5 



66 



3.06 



5 



44 



5 



66 



2 



94 



3 



06 



1 



04 



1.00 



and from 1.00 to 4.76. The average range of the ratio, by the 

 white atmometer, for the two plants, is 1.0 to 6.3, and the average 

 range of the ratio by the brown instrument is 1.0 to 5.6. It is 

 to be remembered that these ratios represent average conditions 

 for the hour, and, consequently, to compare the ranges just given 

 with those of the index obtained from the paper test, it is neces- 

 sary to use for the latter hkewise, the range of the average con- 



' Livingston, B. E., Operation of the porous cup atmometer. Plant World 13: 

 111-118, 1910. 



