ABSTRACT
Geomorphology, like many subjects in the scientific curriculum, had a double birth or, if we prefer another metaphor, distinct phases of germination and flowering. Much, if not all, that geomorphology teaches is implicit in the pages of Hutton and Playfair and they are normally accounted the founders of the subject. Yet the real nature and extent of ‘denudation’ was by no means fully grasped by their successors. Throughout his earlier life, at least, Lyell held fundamentally erroneous views on the origin of valleys. British geology was, perhaps, too preoccupied with the philosophical and biological implications of the new earth knowledge to have time or mind for a really close scrutiny of the existing landscape. The general nature of sub-aerial wastage was accepted as manifest; its efficacy as compared with the erosive powers of the sea was not acknowledged. Nor was the notion that valleys were in general modified tectonic fissures at all lightly abandoned. Half a century’s progress still left it possible for George Greenwood in his Rain and Rivers (1857) to claim the defence of‘Hutton and Playfair against Lyell and all comers’. Such a claim administers a salutary shock to those who have lightly concluded that Lyell was the lineal descendant and disciple of Hutton. It has been far too readily assumed that because the ‘cycle of erosion’ was implicit in uniformitarian doctrine, its corollaries were explicit in the minds of the earlier geologists.
