Why is it when giving a grid position on land you go across the map before you go up the map, but on a chart, you give the latitude before longitude there for going up the chart before going across. Why are they opposite?
My guess is that latitude was easier to determine based on the position of the sun / North star and became the primary position fix. Longitude arrived a bit later once they had worked out how to make clocks read accurately.
Ordnance Survey is based on a X and Y grid and traditionally your read the X first and Y second.
Thanks for the inputs Guy and Neil. I initial thought I had got it wrong when I recently started studying marine navigation. You would think that they would both be the same!
Tickler
