  X-ray and optical observations have shown that the supernova explosions and
stellar winds of the starburst in NGC 2146 produce an outflow of hot material
along the minor axis. This outflow is expected to have a more or less conical
shape, on either side of the galactic plane, and cone walls of cooler material
where the outflow is in shock contact with halo gas. We attempt to determine
the geometry (diameter at the base and opening angle) and the physical
parameters (velocity and density) of the material in the cone walls from the
optical emission line and radio observations presented here, and from published
X-ray, radio, and optical observations. We compare the outflow of NGC 2146 with
the outflow of M 82.
