  We construct an example of a uniquely ergodic measured foliation on a surface
such that the associated translation flow on the orientation double cover is
minimal but not uniquely ergodic. We then prove a geometric criterion for the
horizontal foliation of a quadratic differential to be uniquely ergodic. The
second theorem generalizes a result of Trevi\~no for the horizontal flow on a
translation surface, as well as Masur's criterion for unique ergodicity of the
horizontal foliation.
