The secondary current distribution is calculated for current flow between planar electrodes placed on two radii of an annular section, forming a cell with concentric cylindrical walls. The curved walls are insulators, and there are no variations in the axial direction of the cylindrical coordinate system. The anode is taken to be reversible, and the cathodic reaction-kinetics function is Linear. The current distribution is found as a function of geometric ratios and a dimensionless polarization parameter. It is suggested that a cell of this geometry may be used to measure quantitative throwing power as well as to observe qualitative properties of plating-bath solutions.