1. The Stone age, in which man’s cutting implements, working tools and weapons of war, were of stone. This age is sometimes subdivided, the older part being called “Palaeolithic” [old stone], and the more recent, “Neolithic” [new stone].
2. The Bronze age, its implements being chiefly of copper or brass.
3. The Iron age, where iron first appears.
Now the great question—the only one that comes within our range of inquiry—is the date of these traces of ancient men. When did the men of the Stone age and of the Bronze and the Iron age live?
In the outset, it can not be assumed reasonably that this stone-age civilization, apparent in Northern and Western Europe, was necessarily universal at that time over all the earth. It may have been coeval with the very high civilization of Egypt and even of Babylonia, Phenicia, Etruria. We must consider that large portions of the world in those early times were unknown to each other, even as interior Africa has been unknown to the civilized world almost to this very hour. It is therefore entirely an open question—Was this stone-age civilizationpre-Adamic? Was it anterior to Noah; or shall its place in the ages be found contemporaneous with the early civilized nations of known history?
It is important here to premise yet further that the earth’s surface has at no very remote period experienced considerable elevations and depressions and changes of temperature. Especially there are proofs of an extraordinary period of glaciers and icebergs, by means of which huge bowlders have been transported from their ancient beds and scattered afar, and vast masses of debris, rocks ground down and pulverized, mixed with sand, gravel, and small stones, have been heaped up along the line of the glaciers and spread over their track. It is not easy to conceive the full measure of utility resulting from this great ice-flood and glacier movement, in grinding the surface of the rocky strata and mixing this finely pulverized matter with decomposed vegetable elements to prepare soil for our earth’s surface.
The opinion is becoming general that man was not placed upon the earth until after this glacial and ice-bound age. He could not have lived here then: certainly not in portions reached by glacial action and ice floods; the earth was not ready for him till afterwards. No decisive traces of his presence at an earlier period have been found. Such traces appear shortly after.
The problem of the time of man’s first appearance upon the earth is for the most part one of estimates; and these estimates in the department of geology are comprised, at least chiefly, under these five heads:
(1.) The time required for the alluvial deposits underneath which his remains or implements have been found.
(2.) The time required for the growth of the peat under which we find man or his works.