Above the "water-table" the water is held by capillarity, and the percentage of water held decreases as we approach the surface where there may be perfect dryness.
Capillarity and Surface Tension.-Reference should be made to the article Capillary Action for the general discussion of this phenomenon of liquids.
If a number of small enough holes be drilled through a solid substance which is not wetted by the liquid, our knowledge of the phenomena of capillarity shows us that it needs pressure to force the liquid into the holes.
In its full extension the subject of capillarity is very wide.
It tends to improve the tilth and the capillarity of the soil by binding sands together somewhat and by opening up clays.
Not only does water move upwards, but it is transferred by capillarity in all directions through the soil.
Water will rise in clay by capillarity to a height of 50 in., in sand to as in.