Review: There has been so much written about human changes to the environment that it is all too easy to forget that the very concept of 'environment' is not a fixed entity but a variable concept depending on context. This is not to argue towards a post-modernist perspective (whatever that might be) for that is just one other view. The whole idea of our conception of the development of the planet has changed, and radically so, in the past few hundred years. The aim of this slim text is to provide us with some of the detail.

We start with an overview of the case to be presented. Rather than collect random ideas, the author sets her work in the context of Kuhnian paradigms and then uses an example (in this case, continental drift) to show how our ideas have changed (and soberingly, how one period's orthodoxy becomes another's idiocy!). Chapter two turns to look in more detail at the way the origin and age of the Earth have been seen. We start with the biblical interpretation and move on through a series of ideas to Hutton's views. Chapter three takes the story further starting with refutations of Hutton's ideas and discussing the contribution made by Lyell. The importance of this work is that it highlights the contribution that Lyell made to furthering geology as a science. Chapter four turns to the role of water on the surface and the gradual awareness of the role of glacial action in shaping landforms. The value of this work was that it moved against biblical ideas still being held and led the way for a recognition of climate change. Chapter five looks to Darwin but not for ecology but geomorphology and his observations on the Beagle voyages. The book now turns to a more specific area of study and location; US fluvial geomorphology. In chapter six and seven we see how fieldwork in the US led to a refinement of understanding and towards the "Davisian cycle" that was the staple diet of geomorphologists until recently. Chapter 8 brings this more up to date with the work, initially, of Horton and then one of the great 20th Century figures - Strahler. In a useful but too rare touch anywhere we see not only his ideas but also the evolution of them through a "tree" of pupils and colleagues. Chapter 9 brings us right up to date using ideas of chaos theory.

This is a very interesting history of ideas from one field of study. What makes this more interesting than many accounts is that we have not only the ideas but also people's reactions to them and the counter-reactions etc. making this a dialogue in science rather than a list of papers. For geomorphologists it would make a very useful grounding in the subject's development. Others wishing to see how a subject can change (and how personalities matter as much as science) would do well to read this text.