make through the forest, or the buffalo across the prairie. The cities themselves are but temporary encampments of herding groups of animals, determined or conditioned by such natural features as a river or a plain, an estuary or a mountain, a coal-bed or a forest. How relatively slight a geographical disturbance is made by the building of a city—even a modern capital city—may be realised by recalling, that practically the whole of the new town of Edinburgh is built out of a local sandstone quarry, so small that its floor would not afford camping space to a travelling circus.
The foregoing account is intended to suggest the geographer's vision as it is in his naturalist or cosmic mood. But the geographer is himself a man and a citizen, and as geographer he still has his humanist or idealist mood. Viewed in his humanist or idealist mood, the world drama undergoes for the geographer a profound change. The perspective changes from the cosmic to the human focus. The typical river valley, which is the essential regional unit of the geographer, is no longer a mere fold of the earth's crust in its endless and aimless cycle of changes, but is conceived as the realisation of a great purpose. The long geological history of the river valley is seen as the preliminary preparation to fit it to be the scene of the exploits and aspirations of a godlike race of beings, such as is suggested and foreshadowed