the first rigorous system of latitude and longitude lines is credited to hipparchus. he employed a sexagesimal system that was derived from babylonian mathematics. the meridians were sub-divided into 360°, with each degree further subdivided into 60 (minutes). to measure the longitude at different locations on earth, he suggested using eclipses to determine the relative difference in time. the extensive mapping by the romans as they explored new lands would later provide a high level of information for ptolemy to construct detailed atlases. he extended the work of hipparchus, using a grid system on his maps and adopting a length of 56.5 miles for a degree.