  Direct limits are set on $WWZ$ and $WW\gamma$ three-boson couplings in a
search for $WW$ and $WZ$ production with high transverse momentum in
$p\overline{p}$ collisions at $\sqrt{s} = 1.8$ TeV, using the Collider Detector
at Fermilab. The results are in agreement with the SU(2) $\times$ U(1) model of
electroweak interactions. Assuming Standard Model $WW\gamma$ coupling, the the
limits are interpreted as direct evidence for a non-zero $WWZ$ coupling at
subprocess energies near 500 GeV. Alternatively, assumiong identical $WWZ$ and
$WW\gamma$ couplings, bounds $-0.11 < \kappa < 2.27$ and $-0.81 < \lambda <
0.84$ are obtained at $95\%$ CL for a form factor scale 1000 GeV.
