  We compare the expected effects of so-called gravitationally enhanced
depolarization of ultracold neutrons to measurements carried out in a
spin-precession chamber exposed to a variety of vertical magnetic-field
gradients. In particular, we have investigated the dependence upon these field
gradients of spin depolarization rates and also of shifts in the measured
neutron Larmor precession frequency. We find excellent qualitative agreement,
with gravitationally enhanced depolarization accounting for several previously
unexplained features in the data.
