Mercury stations retrograde on September 5, 1917 at 4° Libra, and direct on September 28 at 19° Virgo — 23 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.