=================================================================== |No 242 Miss.|No. 643 Cal. +------------+------------ |Hog-wallows |Black Adobe. | soil. |Contra Costa | Jasper Co. | Co. |Mississippi.|California. -----------------------------------------+------------+------------ Weight of gravel over 1.2 mm. diameter } | .83 | “ “ between 1.2 and 1 mm } | | “ “ between 1 and 0.6 mm | 1.19 | Fine earth | 97.98 | 100.00 +------------+------------ | 100.00 | 100.00 FINE EARTH. | | | | Hydr. Value. | Diameter. | | -------------------------+---------------+ | Clay <.0023 mm | ? | 48.00 | 45.96 | | | { <0.25 mm | .010 | } 35.18 | 37.64 { 0.25 mm | .016 | } | Silt { 0.5 mm | .025 | 5.50 | 2.74 { 1.0 mm | .036 | 3.74 | 3.31 { 2.0 mm | .047 | 2.54 | 2.95 { 4.0 mm | .072 | .20 | 2.39 | | | { 8.0 mm | .120 | .27 | 1.68 { 16.0 mm | .160 | .90 | .79 Sand { 32.0 mm | .30 | 1.67 | 2.36 { 64.0 mm | .50 | 2.00 | | +------------+------------ | | 100.00 | 100.00 -------------------------+---------------+------------+------------ It will be noted that in both these extremely heavy soils the sum of the clay and finest sediments is a little over 83%. It should be stated that both these soils after being thoroughly wetted become so adhesive that it is almost impossible to travel over the tracts occupied by them, and that they are practically almost untillable, being too adhesive when wet; yet if allowed to dry to a certain extent (varying within very narrow limits) they turn up by the plow in large clods, which after a few hours of sunshine become of stony hardness and will resist all efforts at pulverization or the production of tilth.[34]