He, of course, sought an outlet in vain, and found himself standing at the base of an immense rampart, which shot sheer up two hundred and fifty feet in air. He surveyed the structure, and soon discovered that it was no trifling barrier, but a mighty pile of rocks, that showed themselves almost as massive and firm as the mountains which they bound together. At first Behemoth thought although it would be idle to attempt to shake the whole mass at once, that yet the separate parts might be removed block by block. With this purpose he endeavored to force his white tusks between them, but it was in vain; they were knit too firmly together to be sundered. At length the great Brute was maddened by these fruitless efforts, and retreating several hundred rods, he rushed against the wall with tremendous strength and fury.

The Mound-builders, who overlooked the structure, trembled for its safety, but it stood stiff, and the shock caused Behemoth to recoil discomfited, while the earth shook with the weight and violence of the motion. Over and over again these assaults were repeated, always with the same result. Wearied with the attempt, the Mastodon desisted, and returned to feed upon the diminished pasturage, which he had before deserted.

Part Second, pages 122-123