In an active way it directs them; but they in turn clothe the passive earth with a mantle of humanity.

This mantle is of varied weave and thickness, showing here the simple pattern of a primitive society, there the intricate design of advanced civilization; here a closely woven or a gauzy texture, there disclosing a great rent where a rocky peak or the ice-wrapped poles protrude through the warm human covering.

This is the magic web whereof man is at once woof and weaver, and the flying shuttle that never rests.

Given a region, what is its living envelope, asks anthropo-geography.

Whence and how did it get there?
What is the material of warp and woof?
Will new threads enter to vary the color and design?
If so, from what source?
Or will the local pattern repeat itself over and over with dull uniformity?
[Sidenote: Geographical interpretation of historical movement.] It was the great intellectual service of Copernicus that he conceived of a world in motion instead of a world at rest.