Using elementary apparatus and instrumentation, shaft whirling has been investigated for three cases involving round or flattened shafts in combination with uniform or asymmetric stiffness bearing supports. The type of whirl observed varies with the combination of asymmetries used. Single and double-frequency whirls have been noted, both forward and backward with respect to shaft rotation. Studies of the phase-angle changes required by the running conditions have indicated the reasons for whirl direction and frequency.