St. Columb Major, Cornwall
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.This drawing is orientated toward the south-east. On its reverse, obscured by backing material, is a triangulation diagram used to plot locations accurately. Tin and copper mines are marked, and a key to the symbols used to distinguish them is given at the bottom of the drawing. ."Harmony Cot" is marked as the birthplace of the portrait painter, John Opie (1761-1807). The inclusion of such information seems at odds with the Survey's military emphasis, but it does reflect the interests and training of the draughtsmen, many of whom were professional artists. To the north of St Columb Major lies the ancient monument known as the Nine Maidens, symbolised by a drawing of stones. A dot, annotated "point", appears in the bottom left hand corner of the map. This is probably the coastal station at Trevose Head, a base for the measurement of angles of elevation.
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Military batteries are marked along the coastline in this drawing. The profusion of defensive castles in this area is testimony to the perceived vulnerability of coastal regions. Red blocks indicate individual structures within the complex of Pendennis Castle, built by Henry VIII after his divorce from Catherine of Aragon aroused the hostility of Catholic France and Spain. The nearby castle of St Mawes acted as a seaward deterrent, protecting the anchorage of Falmouth. Half Moon Battery is indicated, as are signal seats along the extreme edge of the coast.
This drawing shows three separate landmasses on the north coast of Cornwall. The area comprising Trevose Head and the estuary of the River Camel at Padstow is drawn at a scale of 2 inches to the mile, as is the inland region south of Tredinnick and Saint Breok Downs to Roche. The area from Hensbarrow Downs to Luxulyan and Saint Blazey is depicted at the larger scale of 3 inches to the mile. The drawing is attributed to Robert Dawson (1771-1860) who represented relief by shading in short disconnected lines drawn in the direction of the slopes - a technique known as hachuring. Dawson also estimated altitudes in pencil, depicting highpoints of almost 20 metres at Saint Breok Downs. Pencil intersections spread from the upper-left landmass, indicating lines between fixed points used for triangulation. Dirt marks remain where the map was formerly folded in four. Plans were not stored flat between deal boards until the1820s.
This map features surveyor Robert Dawson's distinctive contouring technique: soft brushwork interlining ('hachuring') combined with numerical notation of relative relief. Dawson has detailed hillforts, medieval castles, barrows and antiquities, including Helmen Tor and St. Prideaux in the north and Fowey Castle and St. Saviours Tower in the south. A coniferous tree plantation is indicated to the right of the moated mound surrounding Restormel Castle, towards the top right of the map. Built by the Normans, the castle had superb defences and was only successfully invaded once in its long history, when Charles I's forces drove out the Parliamentarian garrison in 1644 during the English Civil War. .This map is dated 1805 in pencil on the bottom right-hand corner. Below this, a note of the scale in ink was partly cut off when the margins were trimmed.