The optical pumping of metastable 3He atoms with circularly polarized resonance radiation from a 4He light source has been carried out at several 3He gas pressures and at different pumping light intensities and metastable atom concentrations. The dependence of both the equilibrium nuclear polarization and the pumping time on both the metastable atom density and the intensity of the pumping radiation is in satisfactory agreement with the theoretical predictions of Daniels and Timsit.