46 



BULLETIN 835, U. S. DEPARTMENT OF AGRICULTURE. 



slope of the ground has in assisting capillarity to draw wate: 

 conveying 1 channels and storasre reservoirs. 



iTom 



Table 34, — Quantity of icater removed from -the tanks at various times, 

 expressed in depth, on an area equal to cross section of flume. 









Flume. 







Number 

 of days. 















• 



1 









34 



32 



31 39 



42 



43 





Inch es. 



Inches. 



Inches. 



Inches. 



Inches. 



Inches. 



1 



G. 11 



5. 65 



6.11 



4.58 



6. 11 



4.28 



3 * 



12.22 



10.99 



9.76 



7.93 



8.54 



G.41 







17. 72 



15.26 



11.59 



9.46 



9.76 



6.77 



10 



29. 61 



25. 64 



15. 86 



11. 59 



11.59 



7. 56 



15 



41.20 



30.02 



19.22 



13.42 



12.81 



8.54 



20 



53.40 



47.90 



22.28 



14. 95 



14. 50 



9.16 



40 



91. -58 



85.75 



32.33 



19.08 



18. 63 



9.64 



Table 35 gives the number of cubic centimeters of moisture re- 

 quired to advance the moisture in the flumes an average distance of 

 1 inch at different periods of time. One point worthy of note in this 

 table is the fact that flume 43 used about the same quantity of water 

 per inch throughout. It must be kept in mind that this flume was 

 closed to evaporation and that no water escaped from this tank that 

 was not confined within the wetted soil area of the flume. The other 

 flumes were all open to evaporation. The figures seem to indicate 

 that as we recede from the vertical the quantity of water required 

 per inch is less. However, these figures are so confused with the 

 evaporation that they do not indicate the true facts as to the require- 

 ment of the soil itself when placed at these different angles. The 

 evaporation factor is confused, for the reason that the soil within the 

 flume contains relatively different percentages of moisture, which 

 has an influence upon the quantity of evaporation. Furthermore, 

 the wetted area of soil differs so greatly in the several flumes and 

 hence that the area exposed to evaporation is much different. 



Table 35. — Average quantity of water required to advance wetted area in flumes 



1 inch. 









Flume. 







Number 

 of days. 

























34 



32 



31 



39 



42 



43 





c.c. 



c.c. 



c.c. 



c.c. 



c. c. 



c.c. 



1 



385 



419 



500 



406 



596 



446 



3 



447 



436 



474 



530 



573 



506 







498 



455 



477 



543 



578 



486 



10 



533 



513 



488 



531 



5S7 



482 



15 



569 



561 



501 



556 



(129 



487 



20 



608 



626 



562 



573 



663 



471 



30 



684 



739 



616 



548 



760 



476 



40 





' 843 



681 



605 



767 



476 



50 









686 

















1 



