1 : 21120 This is a roughly drawn field sketch of the north bank of the Thames, extending from West Thurrock, at the bottom, to Great Warley, at the top. The plan is made up of about 13 irregularly cut pieces of paper watermarked "1794". Some mismatch of detail is noticeable along the edges where the sheets have been joined, and the orientation of the lettering on the component parts is varied. Trigonometrical stations, from which the surveyors took angular readings, are marked 'flag', notably at 'Bulvan Fenn' and just above the low water mark for the Thames. Verron, Charles
1 : 10560 This map, showing the area around Cobham in Kent, is drawn on rectangular sheet lines, enclosed by a black border. Fields are coloured brown where cultivated, and green or blank if untilled. Stonework buildings and structures are drawn in red ink at major settlements. Pencil rays intersecting across the map, discernable beneath the inked detail, are evidence of angular measurements taken by the surveyor between fixed triangulation points. Altitudes on sites of eminence ('spot heights') have been measured and noted in red-ink figures.
1 : 21120 This rough field sketch, or 'foul' copy, was produced on several pieces of irregularly cut paper joined together and laid on the verso of the triangulation map for southern England. Covering the north side of the Thames, East Ham and Ilford are to the left, and Rainham to the right. The drawing is dominated by a patchwork of field boundaries, with open dotting indicating unproductive enclosed land. The detail recorded here was incorporated in the 'fair' map OSD 132, titled 'Barking'.