First, cut the top and bottom out of the can. Fill the above ground part of the can with water. After an hour, read on the plastic ruler the amount of water that the soil has absorbed. Sandy soil absorbs more than two inches of water per hour. It is very porous, with large spaces between soil particles.
Little water is retained and the sandy soil dries out quickly.
Loam soil absorbs from .25 inches to 2 inches per hour. The soil is loose and porous and holds water quite well. Clay soil absorbs less than .25 inches of water per hour. Clay soil is dense with few air spaces between particles and holds water so tightly that little water is available for plants.