Cyrn y Brain
1 : 31680 The county boundary of Denbighshire and Flintshire is indicated here by a red pecked line. The plan is formally titled, with a note in the top left corner explaining that it has been copied from the original protraction with north facing upwards instead of true. A triangulation diagram appears on the reverse of the drawing: this enabled the draughtsman to plot with prominent topographical features with precision. Many pencil lines radiate from a trigonometrical point at Cefny Fedw, indicated by a dot within a triangle. These represent the angular measurements taken from this point. Giles, John C.