Aug. 20, I9I7 Relation of Soil Water Movement 419 



UPWARD MOVEMENT IN SOILS DIFFERING IN INITIAL MOISTURE 



CONTENT 1 



EXPERIMENTS 



The same soils were employed as in the experiments described above, 

 using parts of the same three preparations of each, carrying approxi- 

 mately 0.5, 1,0, and 1.5 times the hygroscopic coefficient, placed in 

 glass tubes of an inside diameter of 3.0 cm. and 160 cm. long. The 

 glass was of poor quality, and many of the tubes cracked during the 

 experiments, thus with some interrupting the observations and with 

 others preventing any being made. 



In the first and second experiments, those in which the soil moisture 

 was 0.5 and i.o times the hygroscopic coefficient, because of the diffi- 

 culty of satisfactorily tamping the soil into so narrow a tube, the tubes 

 were filled by jarring. In filling a tube the end, covered by fine copper 

 gauze, was first rested upon a large rubber stopper on the cement floor. 

 It was held in position by one operator, who raised it about 6 inches 

 above the stopper and brought it down upon this in a succession of 

 smart blows, while another operator added the soil in a slow stream 

 through a funnel. As the soils in the third experiment were too moist 

 to permit the tubes to be conveniently filled in this manner, the tubes 

 were connected with a metal funnel of the same diameter as the tube 

 by means of rubber hose, and a small tamper, consisting of a one-hole 

 rubber stopper on a wooden rod, was operated through the funnel and 

 kept in constant motion, striking sharp, uniform blows while a slow 

 stream of soil was added. 



After all the tubes had been filled, they were placed upright in a 

 rack, the lower end of each dipping into a metal trough and resting 

 on a strip of 0.25-inch mesh wire screen, the object of which was to 

 facilitate both the entrance of water and the escape of air. Throughout 

 the experiments the water in the trough was maintained at a depth of 

 1.5 inches. In the first two the tubes were allowed to remain in con- 

 tact with the water for 10 days, and in the third 8. The height of rise 

 Vv'as observed at the end of i, 2, 3, 4, and 24 hour intervals during the 

 first day, and after that at the end of each 24-hour period (Table XIX). 

 The readings actually made were to i mm. but to facilitate comparison 

 they are reported only in even centimeters, the difference being negli- 

 gible in comparison with the differences between duplicates. 



INFLUENCE UPON THE RISE OF METHOD OF COMPACTING SOIL 



On comparing the results obtained in the second experiment with 

 those in the third, we suspected that there might have been some dis- 

 turbing factor introduced by the different methods employed in filling 

 the tubes. As a supply of two of the moistened soils, D and H, surface 



1 Mr. Jouette C. Russell assisted in this part ol the work. 



