Berwick St. John
Small red crosses at Baverstoke, at the top centre, and Et Knoyle, at the top left,mark observation points used by the surveyor to plot topographical details and measure distances. The draughtsman has faithfully recorded the relative relief of the hills and indicated areas of woodland, using various shades of green to distinguish woods from grassland. The ancient circular earthworks of Chiselbury are marked by concentric rings on White Sheet Hill, in the centre of the drawing.
1 : 31680 Although this drawing was surveyed six years before the obligatory inclusion of archaeological sites on drawings, several are featured. The most famous of these is Stonehenge, to the right of the drawing. Ancient camps, earthworks, castles and grave mounds ('tumuli') pepper the area, indicated by concentric shapes and a title in neat script. Their inclusion reveals the meticulous nature of the survey. To the right of the drawing, opposite Wishford, a trigonometrical station is indicated by a dot within a circle (annotated 'Col. Mudge's station' - Major-General William Mudge was Superintendent of the Ordnance Survey). This station denotes a point from which angular measurements were taken. In the right hand margin of the drawing a point titled "End of Base" marks the end of the Salisbury Plain baseline: an important measurement allowing for the triangulation of the area. Crocker, Edmund