  We observed an unexpected bending of a horizontally held palladium plate at
150$^{\circ}$C under a small external shearing stress. The deformation was
fastest at the nominal composition of PdH$_{{\rm 0.1-0.2}}$, which is in the
$\alpha+\beta$ phase. We also observed that a plate warped back and forth
during a cycle of absorption and desoprtion of hydrogen when it was hung
vertically, which does not have a reasonable explanation.
