In 17-32, the corners traditionally set one bar to the person you just passed, then one bar to the next person to pass. In a variant for [19-24] 1c turns BH in PdB.
2 chords. On 2nd chord 1W crosses down to R of P, 2W moves 1 place up and 2M crosses to her place, so 1c faces 2c across.
Notes: The RSCDS prescribes a 4c set, but the tradition is a longwise set 'for as many as will'.
Note that both times the couple moving UP makes the arch.
Note: older instructions tell 1c to turn once LH on 23-24; the current (revised) instructions leave that unspecified.