Rotation curves for M 15, NGC 1851, NGC 2808, and NGC 5927. Left panels: V_r in the system of the cluster as a function of distance from the centre projected onto the axis perpendicular to the best-fit rotation axis found in Fig. 16. The number of stars in each quadrant is also shown. Right panels: comparison of the cumulative V_r distributions of stars with X(PA0) > 0.0 (continuous lines) and X(PA0) < 0.0 (dashed lines). The probability that the two distributions are drawn from the same parent population (according to a KS test) is reported in each panel. We show rotation curves only for the four clusters with P_KS< 2.5%.