westend wrote:
FWIW, I've used those ship's clocks, mainly for shooting location with a sextant. ... A couple of seconds of inaccuracy would put your location 100 miles off, East or West. I have no clue how they did it before radio, accuracy was probably not an issue.
IIUC, it was a huge issue, for exactly the reason you say! Ships' clocks had to be incredibly accurate, and designing one that would be was a matter of national security. I saw a PBS show on this once... and I think there is a book, Longitude.
May not be an issue for Mex or most RVers, though :).
