[Illustration: Fig. 77.--Section across valley of the Somme: 1, peat, twenty to thirty feet thick, resting on gravel, _a_; 2, lower-level gravels, with elephant-bones and flint implements, covered with river-loam twenty to forty feet thick; 3, upper-level gravels, with similar fossils covered with loam, in all, thirty feet thick; 4, upland-loam, five to six feet thick; 5, Eocene-Tertiary.] At length, Dr. Regillout, an eminent physician residing at Amiens, about forty miles higher up the Somme than Abbeville, visited Boucher de Perthes, and, upon seeing the similarity between the gravel terraces at Abbeville and Amiens, returned home to look for similar implements in the high-level gravel-pits at St. Acheul, a suburb of Amiens. Almost immediately he discovered flint implements there of the same pattern with those at Abbeville, and in undisturbed strata of the gravel terrace, where it rested on the original chalk formation, at a height of 90 feet above the river. In the course of four years, Dr. Regillout found several hundred of these implements, and in 1854 published an illustrated report upon the discoveries. Still the scientific world remained incredulous until the years 1858 and 1859, when Dr. Falconer, Mr. Prestwich, Mr. John Evans, Mr. Flower, Sir Charles Lyell, of England, and MM. Pouchet and Gaudry, of France, visited Abbeville and Amiens, and succeeded in making similar discoveries for themselves. Additional discoveries at St. Acheul have continued up to the present time whenever excavations have gone on at the gravel-pits. Mr. Prestwich estimates that there is an implement to every cubic metre of gravel, and says that he himself has brought away at different times more than two hundred specimens, and that the total number found in this one locality can hardly be under four thousand. "The gravel-beds are on the brow of a hill 97 feet above the river Somme," and besides the relics of man contain numerous fluviatile and land shells together with "teeth and bones of the mammoth, rhinoceros, horse, reindeer, and red deer, but not of the hippopotamus,"[CW] bones of the latter animal being found here only in the gravels of the lower terraces, where they are less than thirty feet above the river, and mark a considerably later stage in the erosion of the valley. While many of the implements found at Amiens seem to have been somewhat worn and rolled, "others are as sharp and fresh as when first made.... The bedding of the gravel is extremely irregular and contorted, as though it had been pushed about by a force acting from above; and this, together with the occurrence of blocks of Tertiary sandstone of considerable size, leads to the inference that both are due to the action of river-ice. In the Seine Valley blocks of still larger size, and transported from greater distances, are found in gravels of the same age." [Footnote CW: Prestwich's Geology, vol. ii, p. 481.]