The ¶ and § velocities measured for the stainless-steel core, = 5743 75 m/s and = 3092 22 m/s, are approximately twice the Massillon Sandstone values, which seems reasonable. The measured stainless-steel / ratio is 1.86 .04, which is slightly stiffer than the Poisson solid value of = 1.73, as expected.

The ¶ and § velocities measured for the dry Massillon Sandstone are
= 2918 32 m/s and = 1731 99 m/s. This
represents an / ratio of = 1.69 .12,
which is a Poisson solid to within error bounds.
The ¶ and § velocities measured for the saturated Massillon Sandstone are
= 3380 78 m/s and = 1744 201 m/s. This
represents an / ratio of = 1.94 .25, which is not
very Poisson-like, and is similar to the stainless-steel sample,
neglecting the pessimistic error bounds. When water fills the pores,
its effect is to ``stiffen'' the resulting saturated sample. This has
a tendency to increase *K*_{s} and hence , compared to *K*_{d} and
. However, , and the increase in saturated
density over implies that will be slightly
smaller than . These intuitive predictions are
fairly well validated by our lab measurements.

11/18/1997