  In the process e+e- to hadrons, one of the effects of gluon emission is to
modify the 1+cos(theta)**2 form of the angular distribution of the thrust axis,
an effect which may be quantified by the longitudinal cross-section. Using the
OPAL detector at LEP, we have determined the longitudinal to total
cross-section ratio to be 0.0127+-0.0016+-0.0013 at the parton level, in good
agreement with the expectation of QCD computed to Order(alpha_s**2)
Comparisions at the hadron level with Monte Carlo models are presented. The
dependence of the longitudinal cross-section on the value of thrust has also
been studied, and provides a new test of QCD.
