Exploration & Places
Surveying Across the Seas, Part 3: Sextants, Almanacs, and the Surveyed Ocean
How sextants, chronometers, astronomical tables, and hydrographic surveys made ocean navigation repeatable.
From the Index
Finding a vessel’s position and way at sea, including the history of navigational observations and equipment.
Exploration & Places
How sextants, chronometers, astronomical tables, and hydrographic surveys made ocean navigation repeatable.
People of Surveying
How John Harrison’s marine timekeepers turned reference time into a practical east-west position at sea.
Exploration & Places
How latitude, dead reckoning, soundings, and disciplined observation guided sailors before dependable longitude.