  Time-resolved local induction measurements near to the vortex lattice
order-disorder transition in optimally doped
Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ single crystals shows that the
high-field, disordered phase can be quenched to fields as low as half the
transition field. Over an important range of fields, the electrodynamical
behavior of the vortex system is governed by the co-existence of the two phases
in the sample. We interpret the results in terms of supercooling of the
high-field phase and the possible first order nature of the order-disorder
transition at the ``second peak''.
