. Soils, their properties and management. Soils. 308 SOILS: PBOPBETIES AND MANAGEM^ENT ing on the texture and structure of the soil and the amount of moisture present. 220. Measurement of conductivity. — Ordinarily the conductivity of a soil is measured by applying a constant source of heat as quickly as possible and measuring the change in temperature by means of thermometers set in the soil at regular intervals. (See Fig. 48.) The soil in question should be homogeneous in composition and of uniform compaction, and should contain a definite mois- ture content. It should of course be at a temp
. Soils, their properties and management. Soils. 308 SOILS: PBOPBETIES AND MANAGEM^ENT ing on the texture and structure of the soil and the amount of moisture present. 220. Measurement of conductivity. — Ordinarily the conductivity of a soil is measured by applying a constant source of heat as quickly as possible and measuring the change in temperature by means of thermometers set in the soil at regular intervals. (See Fig. 48.) The soil in question should be homogeneous in composition and of uniform compaction, and should contain a definite mois- ture content. It should of course be at a temperature equilibrium before the heat is applied. Ordinarily radia- tion and convection currents are diminished somewhat by inclosing the soil in an insulated compartment. The study of heat moA^ement downward instead of laterally is to be recommended, in order that unnecessary air circulation may be avoided to some 6 4 t t i 0O/l^ 777777. tJa I^iG 48 —Longitudinal section of apparatus for the study of heat con- ductivity of soil (C), water at constant temperature, {£), ther- mometer, (P), copper plates, (F), screw clamp for pressing soil firmly against source of heat, (r), skids for soil box. 221. Effect of texture on conductivity of heat. — The conductivity of a soil is affected by a number of factors. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lyon, T. L. (Thomas Lyttleton), 1869-1938; Fippin, Elmer O. (Elmer Otterbein), 1879-1949; Buckman, Harry Oliver, 1883-. New York, Macmillan
Size: 1959px × 1276px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlyontlth, bookcentury1900, bookdecade1910, bookyear1915
