1914] 



OTIS— TRANSPIRATION OF WATER PLANTS 



473 



distance between the horizontal lines representing the evaporation 

 from the free water surface and that from the water surface and 

 plant surface together represents the evaporation due to the plant 

 surfaces alone. 









1 



TABLE 



; iv 

















Comparative evaporation 



f IN 19 



IO 











Z S. 



W < 



Conditions 



Amounts of evaporation from the tanks (cc. of water added) 



Date 





22 



1 





>> 



X! 













£1 



.fi * u 



u fi 



1 



1 



15 



1 



9 



is 







< 



6 





< 



H 



Pi 



u 



■$■ 



O 



450 



u 



Aug. 10. . 



Day 



834 



519 



1400 



1200 



470 



550 



400 



10. . 



18 



Day and night 



1650 



1400 



1715 



175° 



1015 



1425 



1150 



1375 



11. . 



12 



Day 



1750 



1250 



2400 



2250 



1215 



1250 



1300 



1 100 



11. . 



12 



Night 



1150 



1030 



987 



io53 



75° 



IO9O 



975 



IIOO 



12. . 



10 



Day 



1600 



975 



2585 



2650 



9OO 



1080 



1 140 



750 



12. . 



14 



Night 



1500 



1575 



1300 



1250 



990 



1550 



1225 



1570 



13- • 



11 



Day 



,1770 



975 



2490 



2385 



975 



IISO 



790 



660 



13- • 



13 



Night 



988 



940 



1000 



1 193 



630 



IOOO 



910 



II20 



^0 



14. • 



10 



Day 



1730 



995 



2425 



2445 



905 



IO90 



835 



762 



14. • 



14 



Night 



745 



750 



887 



820 



475 



730 



715 



767 



IS- • 



8 



Day- 



1 145 



500 



1845 



1840 



575 



673 



500 



407 



16. . 



9 



Day 



940 



553 



1247 



1245 



450 



610 



452 



425 



16.. 



14 



Night 



650 



5S3 



654 



650 



420 



600 



500 



500 



17. • 



10 



Day 



1 495 



8i5 



2060 



1785 



630 



863 



580 



678 



19. . 



II 



Day 



2070 



1317 



2890 



2673 



1 185 



I550 



1340 



1 130 



19. . 



13 



Night 



1305 



1300 



139* 



1358 



863 



1327 



1228 



1250 



20. . 



II 



Day 



2058 



1235 



2670 



2565 



970 



U05 



IOOO 



IO63 



20. . 



2 3 



Night and day 



2950 



2150 



3728 



3378 



1435 



2063 



1837 



1913 



21. . 



12 



Night 



783 



685 



890 



900 



395 



785 



655 



595 



26. . 



25 



Day and night 



2920 



2075 



3470 



3255 



1675 



2175 



1725 



1918 



27. . 



7 



Day 



1042 



575 



1590 



1500 



555 



805 



543 



460 



27. . 



13 



Night 



955 



95° 



925 



865 



59° 



4& 



850 



860 



990 



28. . 



25 



Day and night 



2755 



2070 



3660 



3375 



1587 



2l8o 



2IOO 



1395 



29.. 



10 



Day 



2267 



1443 



3040 



2587 



8lO 



1550 



95' 



1040 



29. 



13 



r ai 



Night 



1080 



975 



1305 



1 -'35 



65O 



I055 



1045 



905 



Totals fo 



n approximate 



■ 

















period c 



>f 32- 



\ hours (cc. of 



















water ad 



ided) 



^fc 



38,132 



27,60v 



48,561 



46,207 



2I,H5 



29,406 



24,813; 



24,273 





/ 





fl 7 %J \ 



1 



■ * %J 



■ / • 





1 



1 



WW w ^^w 



most instances the 



from the 



emersed 



water plants transpire during the night. An exception 

 is the case of the water lily, in which the evaporation was usually 



