The answer appears on the seventy-sixth page of the book.

The other men and even women rode me with their real sexual parts or with godemiches.

It is not so much movement in Time of which we are conscious as movement which is timeable.

Curiously enough, there were fluorescent displays underground that could be enjoyed without benefit of an ultraviolet lamp. One of these was fox fire, the spectral glow given off by fungi on decaying timber. In the damp darkness of the mine, pine planks 3 inches thick could become feather light and crumbly in a year.