Mercury stations retrograde on October 10, 1915 at 6° Scorpio, and direct on October 31 at 21° Libra — 21 days. From the Earth, Mercury seems to back up against the stars as we overtake it, as a car passed on the highway seems to slide backward. Astrology holds it a time for crossed wires and delays. Computed from JPL's approximate orbits; the stations agree with an almanac's to within minutes.