tors to apply the term "quicksand" to any sand flowing
through an orifice with water.

Sand in its natural bed always contains some fine material, and where
this is largely less than the percentage of voids, it has no material
effect on the pressure exerted by the sand with or without water, as
above noted. If, however, this fine material be largely in excess of the
voids, it allows greater initial compression to take place when dry, and
allows to be set up a certain amount of hydraulic action when saturated.
If the base of the material be sand and the fill be so-called quicksand
in excess of the voids, pressure will cause the quicksand to set up
hydraulic action, and the action of the piston will appear to be similar
to that of a piston acting on purely aqueous material.

Just here the writer desires to protest against considering semi-aqueous
masses, such as soupy sands, soft concrete, etc., as exerting
hydrostatic pressure due to their weight in bulk, instead of to the
specific gravity of the basic liquid. For instance, resorting again to
the illustration of cubes and spheres, it may be assumed that a cubical
receptacle has been partly filled with small cubes of polished marble,
piled vertically in columns. When this receptacle is filled with liquid
around the piles of cubes there will be no pressure on the sides except
that due to the hydrostatic pressure of the water at 621/2 lb. The bottom,
however, will resist a combined pressure due to the water and the weight
of the cubes. Again, assume that the receptacle is filled with small
spheres, such as marbles, and that water is then poured in. The pressure
due to the weight of the solids on the bottom is relieved by the loss in
weight of the marbles due to the water, and also to the tendency of the
marbles to arch over the bottom, and while the pressure on the sides is
increased by this amount of thrust, the aqueous pressure is still that
of a liquid at 621/2 lb., and it is inconceivable that some engineers, in
calculating the thrust of aqueous masses, speak of it as a liquid
weighing, say, 120 or 150 lb. per cu. ft.; as well might they expect to
anchor spherical copper floats in front of a bulkhead and expect the
hydrostatic pressure against this bulkhead to be diminished because the
actual volume and weight of the water directly in front of the bulkhead
has been diminished. Those who have had experience in tying narrow deep
forms for concrete with small wires or bolt