Map of the Geology and Contours of London and its Environs, by R. W. Mylne (1856)

This map is similar in concept to Mylne’s earlier maps however this later, much larger map differs in a number of respects.  First, the scale is some two and a half times greater, permitting features to be shown in clearer detail.  Secondly, contours are shown in continuous lines rather than by shading and thirdly, the geological colouring is more detailed and more accurate than before.