Draughtsman: Verron [Charles]
Medium: Pen and ink on paper
The draughtsman used Balsham Steeple and West Wickham Steeple at the top left of this plan as triangulation points. From these positions, he made angular observations with a theodolite to measure the height of the land and to plot individual topographical features. Pencil rays radiating from these two points record the measurement process.