July i6, 1917 Movement and Distribution of Moisture in Soil 



135 



tubes were then filled in duplicate with the soil containing 3.65, 5.30, 6.52, 

 and 8.24 per cent of moisture. 



The wet and dry sets of tubes were then brought into contact with 

 each other by means of collars, a good contact being secured by bulging 

 the soil in each tube slightly above the top. The open ends of the tubes 

 were then made air-tight by sealing with corks that had been dipped in 

 paraffin. In this manner an 8-inch column of wet soil was in contact 

 with an 8-inch column of drier soil. In order to study the movement of 

 water in these soils, a loop was attached to the corks at each end of the 

 tube, care being taken that each loop was equidistant from the center 

 of the tube. The tubes were then suspended horizontally from hooks 



ffefafive disfribution of moisture at varieui times 



■ I" >^^ ■Se ction In dri/ Section 



i 

 s 



6 



t' 



V 2 

 *> J 



^S 



M 



6 



1:: 



^^36f 



<?f J6% 



2f S6% 



jUsJz 



s.JO^ 



6^-?>5 



8.2 1% 



il/te: of separation between nvst and dn^ soils 



Fig. 17. — Diagram showing the effect of varying initial percentages of water on the horizontal distribution 

 of moisture in drier soils in contact with a wet soil having 24.36 per cent of water. The top line of each 

 series represents the original distribution. 



by the loop at the wet ends, while the loops at the drier ends of the col- 

 umns were attached to one arm of a balance. 



As moisture moved from the wet into the drier soil the equilibrium of 

 the balance was disturbed and more weights were added. The weights 

 added at the end of each week were recorded during the period from 

 March 22 to September 6, 191 6. 



The results of the experiments are found in figure 17, which shows the 

 relative loss in the wet and the corresponding gain in the drier soil at the 

 end of weekly intervals. 



It will be noticed that during the first two weeks the soil that was 

 wettest at the beginning gained less water than the others. From the 



