Progress thereafter was rapid, perhaps too rapid. Notable finds were soon followed by attempts to freeze knowledge into chronologic classifications. R. Rigollot, Gabriel de Mortillet, Edouard Lartet, Milne-Edwards, and Henry Christy found in the river terraces and the caves of France innumerable and varied evidences of man’s activity in the Great Ice Age. Mortillet named various cultures from the places where stone tools were found, and then, in 1869, he set them up in a chronological series.[5] Modified by later discoveries, the series ran as follows, beginning with the oldest: Chellean, Acheulean, Mousterian, Aurignacian, Solutrean, and Magdalenian. (Most prehistorians now use the word Abbevillian instead of Chellean because later research proved that the tools found originally at Chelles were Acheulean in type, while those found at Abbeville were earlier.) In the light of present knowledge, the list is much too simplified. It is based only on European finds, yet it is supposed to fit the world picture. For more than fifty years it has served as a scientific straitjacket, patched with new material here and there, but still gaping at the seams as the husky young giant of archaeological science grows in stature. [Illustration: _Time scale of early man in a limited area of Europe, as estimated by Robert J. Braidwood._] Enter the Eolith One of the early difficulties that Mortillet’s list of cultures encountered was the discovery of implements that preceded his first culture, the Chellean—or Abbevillian—in time and type. Cruder axes from older levels had to be called Pre-Chellean (see illustration, page 71). In England scrapers and other crude tools cropped up in formations that go back more than 500,000 years. Then eoliths—“dawn stones”—appeared. They were irregular-shaped pieces of flint with chips knocked off here and there. Often the chipping looked purposeful; the flakes made an edge or a point that could be used to scrape or drill.