behind them houses, tombs, fortifications, temples, implements for use, and ornaments for decoration.
From the careful study of these remains, it would appear that prehistoric archæology may be divided into four great epochs:
1. That of the Drift; where man shared the possession of Europe with the Mammoth, the Cave bear, the woolly haired rhinoceros, and other extinct animals. This we may call the "Palæolithic" period.
2. The later or polished Stone Age; a period characterized by beautiful weapons and instruments made of flint and other kinds of stone; in which, however, we find no trace of the knowledge of any metal, excepting gold, which seems to have been sometimes used for ornaments. This we may call the "Neolithic" period.
3. The Bronze Age, in which bronze was used for arms and cutting instruments of all kinds.
4. The Iron Age, in which that metal had superseded bronze for arms, axes, knives, etc.; bronze, however, still being in common use for ornaments, and frequently also for the handles of swords and other arms, though never for the blades.
The three different types of Celts, and the manner in which they are supposed to have been handled.
Without attempting a laborious classification of the records of these epochs, we will speak first of some of the records of the "Bronze Age". The commonest and, perhaps, the most characteristic objects belonging to this age are the so called "celts," which were probably used for chisels, hoes, war axes, and a variety of other purposes.
Bronze celts are generally plain, but sometimes ornamented with ridges, dots, or lines, as in the accompanying figures. More than two thousand specimens of them are known to exist in the different Irish collections, of which the great Museum belonging to the Royal Irish Academy at Dublin contained in the year 1860 no less than six hundred and eighty eight, no two of which were cast in the same mould. They vary in size from an inch to a foot in length. That they were made in the countries where they are found, is proved by the presence of moulds. It is difficult to understand why the celt makers never cast their axes as we do ours, with a transverse hole, through which the
