The notes from the 1970s and 80s were originally intended for studying long-distance leys and landscape geometry on British Ordnance Survey maps.
Simplified formulae for Ordnance Survey maps (1977)
Maximum discrepancy between straight line and geodesic on OS maps (1985)
Adjusting National Grid coordinates for ley-hunting (1986)
Conversion between map (grid) coordinates and image coordinates
Alternative formulae for the Transverse Mercator projection
Length of meridian arc on an ellipsoid
Converting isometric latitude to geographic latitude