  Observations with the Infrared Space Observatory (ISO) SWS spectrometer are
used to constrain the velocity law and wind clumping of the well-studied
Wolf-Rayet (WR) star WR 136 (HD 192163) (WN6). Because the free-free continuum
opacity in WR winds increases steadily with wavelength in the IR, each point in
the continuous spectrum may be regarded as forming in a pseudo-photosphere of
larger radius for longer wavelength. Using this idea in combination with an
analysis of the Doppler-broadened widths of several \ion{He}{2} recombination
lines, we can derive information about the velocity law and clumpiness of the
stellar wind of WR 136. Adopting a $\beta$-law distribution for the outflow
velocity law, we compute the continuous energy distribution and line profiles.
Interestingly,the continuum data are found to constrain the wind to have fairly
low clumping values for the IR-forming region.
