Draughtsman: Dawson, Robert
Medium: Pen and ink on paper
Robert Dawson is author of this drawing, which shows west Wales from Carmarthenshire to Cardigan Bay. One of the best surveyors and draughtsmen, Dawson was employed on the Ordnance Survey for over forty years, also working as an instructor. Below the formal title of the plan, in the top left margin, is an area calculation in black ink. Brushwork interlinging ('hachuring') and colour washes depicting relief are combined with numerical annotations ('spot heights') describing the height of the land. Those altitudes noted in red ink are trigonometrically ascertained; those in black are estimated.