  The UCN$\tau$ experiment is designed to measure the lifetime $\tau_{n}$ of
the free neutron by trapping ultracold neutrons (UCN) in a
magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach
array confines low-field-seeking UCN within the apparatus, and a set of
electromagnetic coils in a toroidal geometry provide a background "holding"
field to eliminate depolarization-induced UCN loss caused by magnetic field
nodes. We present a measurement of the storage time $\tau_{store}$ of the trap
by storing UCN for various times, and counting the survivors. The data are
consistent with a single exponential decay, and we find $\tau_{store}=860\pm19$
s: within $1 \sigma$ of current global averages for $\tau_{n}$. The storage
time with the holding field deactiveated is found to be $\tau_{store}=470 \pm
160$ s; this decreased storage time is due to the loss of UCN which undergo
Majorana spin-flips while being stored. We discuss plans to increase the
statistical sensitivity of the measurement and investigate potential systematic
effects.
