  We report the analysis of optical spectra of the extreme helium star LSS 3184
(BX Cir) to determine its effective temperature and gravity throughout its
pulsation cycle. The spectra were also used to measure its chemical abundances.
  We report rest gravity, log g = 3.38 +/- 0.02, and a chemical abundance
mixture consistent with those reported earlier in a study using an optical
spectrum with lower spectral resolution and a lower signal to noise ratio. Our
analysis decreases the upper limit for the H abundance to H < 6.0 (mass
fraction < 7.1 x 10^-7). Our gravity corresponds to stellar mass M = 0.47 +/-
0.03 M_sun.
  We find that the effective log g varies through the pulsation cycle with an
amplitude of 0.28 dex. The effective gravity is smaller than the rest gravity
except when the star is very near its minimum radius. The change in effective
gravity is primarily caused by acceleration of the stellar surface.
  Based on the optical spectra, we find the temperature varies with an
amplitude of 3450 K. We find a time averaged mean temperature, 23390 +/- 90 K,
consistent with that found in the earlier optical spectrum study. The mean
temperature is 1750 K hotter than that found using combined ultraviolet spectra
and V and R photometry and the variation amplitude is larger. This discrepancy
is similar to that found for the extreme helium star V652 Her.
