General Roy’s Baseline Cannon Monument

Could this unassuming cannon at General Roy’s Baseline Cannon Monument be the starting point of something much grander? Before the days of GPS and satellites, mapping a nation was a monumental task. In the late 18th century, Major-General William Roy, a Scottish engineer, embarked on a mission to create an accurate map of Britain. His tool of choice? Triangulation. General Roy’s Baseline Cannon Monument marks the southeast end of his baseline, a carefully measured distance of approximately five miles, stretching from here to Heathrow Airport. This baseline was the foundation for a network of triangles that would eventually encompass the entire country. Roy and his team used meticulous measurements and innovative instruments, achieving remarkable accuracy for their time. The legacy of General Roy’s Baseline Cannon Monument and the triangulation it represents is the Ordnance Survey, Britain’s renowned mapping agency. So, as you stand here, remember that this unassuming cannon is a testament to the ingenuity and determination of those who sought to chart the world around us. It represents the starting point of a mapping legacy that continues to shape our understanding of Britain’s landscape.