Time difference, distance, average propagation speed, and orientation of the brightening of QSEBs in Hϵ with respect to their counterparts in Hβ. Measurements are based on the first appearance of the QSEB in the respective spectral line. Positive values of the propagation speed d/Δt imply that the QSEB first occurred in Hβ. The orientation angle is measured against the direction toward the closest limb. An orientation of 0° means that the QSEB in Hε is closer to the limb than the QSEB measured in Hβ. The total number of QSEBs measured in both Hε and Hβ is 561.