Warminster
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.
The British Library1808