  Potentials between static colour sources in eight different representations
are computed in four dimensional SU(3) gauge theory. The simulations have been
performed with the Wilson action on anisotropic lattices where the renormalised
anisotropies have been determined non-perturbatively. After an extrapolation to
the continuum limit we are able to exclude any violations of the Casimir
scaling hypothesis that exceed 5% for source separations of up to 1 fm.
