The Antiquity of Man in Europe

This book deals with the antiquity of human being on the European continent. "The first explorer, the original discoverer on a world scale, was primitive man. He had covered the earth before the Europeans of today set for themselves the highly interesting task of rediscovering it and him. After some centuries, this self-imposed, instructive, and pleasure-giving problem is nearly solved. Superficially, at least, the earth has been compassed, the blank spots on the world map of today being few and comparatively small.
The conquest, however, has been largely one of two dimensions. Now that it is nearly over, we are left all the more free to focus the attention on a whole series of antecedent worlds. This is what Europe is at present doing. She is now bent on discovering the prehistoric worlds beneath her very feet. She has found that man's occupation of the earth has not only length and breadth, but also depth, and therefore admits of measurement in three dimensions instead of two.
Surely here is more work for the pathfinder. That success will attend his labors, the discoveries of the past decade offer ample proof. This survey of recent progress is made first of all from the standpoint of chronology. In the second place the evidence of man's antiquity has been arranged under three categories, derived respectively from (1) valley deposits, (2) caverns and rock-shelters, and (3) human skeletal remains."