The Hanle effect for spherical envelopes. Shown are four computed curves, each for a different magnetic field geometry, as indicated in the figure. The square points mark the analytic solution to the case of B = B and give an indication of the numerical accuracy. The vertical and horizontal axes are the same as in Fig. 5. The latitudinal and toroidal fields produce polarizations that are the same in magnitude but opposite in sign, indicating a difference of 90° in the polarization position angle. The dipole and quadrupole fields produce successively smaller variations of the polarization at large values of B_*/B_Hanle. The polarization for the dipole and quadrupole fields does not obtain values as large as those for latitudinal or toroidal fields, for reasons that are discussed in the text.