Fig. 10. Relationship between residual moisture and cos. (a) Satiated condition produced by slow horizontal displacement of air by water in our 15- by 30-cm cell; dark regions are water-filled, light regions air-filled. (b) We then successively tilted the cell to inclinations of 75.5, 60, 41.4, and 0° from vertical. At each step we allowed the cell to drain freely. Capillary fringe at the bottom shows fluid left behind after drainage at vertical (cos = 1.0). Moving upward, the black wavy lines show position of the capillary fringe at cos = 0.75, 0.5, and 0.25. Both the size of fluid blobs left behind and residual saturation increase as cos decreases.