Apart from geological facts, there are three main classes of evidence that serve to distinguish one pre-historic epoch from another.

These are animal bones, human bones, and human handiwork.
Again I illustrate by means of a case of which I happen to have first-hand knowledge.

In Jersey, near the bay of St.Brelade, is a cave, in which we dug down through some twenty feet of accumulated clay and rock-rubbish, presumably the effects of the last throes of the ice-age, and came upon a pre-historic hearth.

There were the big stones that had propped up the fire, and there were the ashes.

By the side were the remains of a heap of food-refuse.