Time-Based Position Fixing

The Sundial Fix

Set a watch — hours, minutes, seconds — and read where the sun stands on the classic flat-earth map. The map is the true Gleason layout (north pole at the centre, the equator a circle at half-radius), so every position is plotted by the same projection as the rest of the suite. At equinox the sun rides the equator circle and time alone fixes its longitude: 15° of arc per hour. Light up one instant, or set several and triangulate.