Historically, how was longitude and latitude determined?

Question

This might sound like a stupid question, but if i determine a longitude and latitude off a map today, would it be the same as one an explorer might have in 1738? The same system was used, wasn't it?

Answer 1

insane has it backwards.....

latitude,as a measure of the height of the North Star, ( or the sun at Local Apparent Noon) was universally agreed to since....well, the Pyramids.

Longitude was a movable idea. The Brits started 0 degrees at the Royal Observatory in Greenwich; the French at Paris, the Russians at St Petersburg.....so, no, a Russian chart would have a different starting point for longitude than an Brit chart in 1738........the French didn't come around till after the Napoleonic Wars...

Someone else is going to have to cite the date of the International Convention On Longitude, but, essentially, the Brits with the largest merchant marine, most ships, most colonies and most charts eventually wore everyone down and we all said ALRIGHT IT STARTS AT BLOODY LONDON!!!

Now, accurately measuring longitude had to wait till John Harrison perfected an accurate sea worthy clock........and he, being Brit, was another reason to start at London......

Answer 2

longitude was determined by the stars, latitude is by a clock.
that is the easy way of putting it.