What were the Stone Ages? In the long years before primitive man learned to weld iron or bronze he formed his weapons and his tools from stone and flint; and geologists and antiquarians have discovered several of these "Ages of Stone" of different periods. For example, the Stone Age which our grandfathers spoke of is now called the Neolithic Age; and in the second quarter of the last century it became gradually admitted that man had existed earlier than that and had swung hammers and chipped edges in what we now call Palæolithic times. That would put man back to the age of the Mammoth. But in the last quarter of last century a new claim arose. The Palæolithic stone weapons and tools were made 150,000 years ago, and were manufactured with great skill and even artistic feeling. Within the last ten years much rougher flint implements of peculiar types have been found in gravels which are 500 to 700 feet above the level of the existing rivers--in the drift of which Palæolithic implements were found. To these older, clumsier weapons and tools--if, indeed, implements they be--the name Eoliths was given by Mr. J. Allen Brown. These Eoliths of the south of England and of Belgium indicate a race of men of less developed skill than the makers of the Palæoliths, and carry the antiquity of man at least as far back beyond the Palæoliths as these are from the present day. So much for speculation. But are the Eoliths truly implements, or are they, as a determined school of anthropologists assert, merely flints which fortuitously resemble the rougher variety of true Palæolith? The strongest attack made on their authenticity comes from Professor Boule and M. Laville, of the French School of Mines, who say that in the flint waste of a cement factory at Mantes they have discovered "pseudo-Eoliths" which are made by the action of the water of the mill, and which resemble every known variety of the so-called "Eolith." Their suggestion is that Eoliths were not made by man at all but were produced by the action of running water. To which the Eolithic anthropologists retort that Eoliths ought surely to be produced by running water now, and that some Seine-made Eoliths would be more convincing. The differences between the Mantes specimens and the "true" Eolith cannot be detected by the untrained eye; but, spite of the French sceptics, the school of believers in the genuineness of the Eolith is growing.