SOILS. 



35 



"The sandy loam contained in t\w 7 ft. of soil when completely filled with water, 

 29.61 in. ; it lost by percolation 6.339 in. and retained 23.271 in. The clay soil began 

 the trial with 37.17 in.; it lost during the (30 days 3.147 in. and still retained 34.023 

 in. in the 7 ft. The sandy loam could retain in its surface foot after 60 days, percola- 

 tion without evaporation 2.83 in. and the clay soil 4.565 in. of water." 



For the observations on evaporation 2 sets of cylinders of 2 each 

 were tiUed with sandy loam and clay soil in the manner described 

 above. "The sandy loam contained, when put in, 18.88 per cent of 

 water and the clay soil 82.63 percent. After the -i tubes had been 

 tilled the soil was removed from one of each set to a depth of 8 in. and 

 as much returned as a loose mulch as was required to again till the 

 tubes level full." 



The tul)es were placed in a ventilating- shaft and a continuous draft 

 of air was maintained across their surfaces from November 26, 1808, 

 to October 6, 1899. At the end of that period the tubes were saw^ed 

 off in 6 in. sections and the distribution of moisture in the colunms 

 determined with the following results: 



Loss of water by surface evaporation from columns of soil 10 feet loinj, ninlcjnd and not 



nrnlched. 



Surface 6 in . . . 

 6 in. to 12 in 

 12 in. to 18 in 

 18 in. to 2-1 in 

 24 in. to 30 in 

 30 in. to 36 in 

 36 in. to 42 in 

 42 in. to 48 in 

 48 in. to 54 in 

 54 in. to 60 in 

 60 in. to 66 in 

 66 in. to 72 in 

 72 in. to 78 in 

 78 in. to 84 in 

 84 in. to 90 in 

 90 in. to 96 in 

 96 in. to 102 in 

 102 in. to 108 in 

 108 in. to 114 in 

 114 in. to 120 in 



Sandy loam 

 Mulched 



Not 

 mulched. 



r cent. 

 8.83 

 12. 97 

 14. 59 



15. 25 

 15.55 

 15.89 

 16. 22 

 16. 29 

 16. 58 

 17.07 

 17.05 



17. 26 

 17.56 

 17.78 

 17.94 

 17.96 

 18. 25 

 18.67 

 18. 53 

 19. 21 



Per cent. 

 7.41 

 14.48 

 14.70 

 14.96 

 15. 53 

 16. 17 

 16. 33 

 16.33 

 16. 10 

 16. 76 

 17.31 

 17. 43 

 17.79 

 17.88 

 17.85 

 17.67 

 18. 05 

 18.09 

 18.63 

 19.95 



Clay soil. 



Mulched Not 

 3 in. mulched. 



Per cent. 

 17.66 

 24. 59 

 26.58 

 26.95 



27. 45 

 27.92 

 27.94 

 28. 24 



28. 46 



28. 47 

 28. 87 

 28.70 

 29.24 

 29.28 

 29. 35 

 29.79 

 30. 32 

 31.15 

 30.47 

 31.25 



Per cent. 

 7.79 

 18.30 

 21. 46 

 26.26 

 26.89 

 27. 16 

 27.61 

 27. 64 

 27. 28 

 28. 23 



27. 79 

 28. 05 

 28. 93 

 28.31 

 28.32 



28. 80 

 29.14 

 29. 16 

 29. 33 

 29. 46 



" It is clear from this table that there has been an upward movement of water and 

 loss through the surface even from the bottom layers of soil in the case of the medium 

 clay, and probably also from the sandy loam. . . . 



"It is certain that a drying of these soils has taken place through a depth of 10 ft., 

 and hence that moisture 10 ft. below the surface of the ground may become available 

 for vegetation purposes at or near the surface." 



It is not certain, however, that this upward movement of water is 

 due entirel}^ to capillarity. It is suggested that "'it may be found 

 that internal evaporation takes place in soils allowing water to pass 

 up through the soil pores of drier soils by gaseous difl'usion and con- 

 dense on the colder soil grains higher up. If this is true, then these 

 observations do not prove that there is danger of capillary rise of 



