Abstract(i)Geodetic. As already mentioned, geodetic fixes were made by trigonometrical methods where possible, otherwise by plane table on the six inch or twenty-five inch map. The Ordnance Survey very kindly computed spheroidal co-ordinates for all the stations in terms of the Retriangulation. Standard errors averaged 0″.1 on the trig fixes, many of the points used being old tertiary points not yet included in the Retriangulation, and 0″.2 on the map fixes.