The Ordnance Survey, the national mapping agency of the United Kingdom, was created to provide the first detailed maps of the nation, to assist with military planning. A triangulation survey commissioned by King George III and the Royal Survey between 1784 and 1790 laid the basis for what would later become the Ordnance Survey. This was motivated by a desire for accurate maps, in advance of a feared French invasion. In the summer of 1784, Major General William Roy created a 5-mile baseline, using glass rods (to prevent expansion and…
