When we consider that some of their porphyry carvings will turn the edge of the best-tempered knife, we are forced to conclude that they possessed that singular process, known to the Mexicans and Peruvians of tempering copper to the hardness of steel.
We find in the mounds adzes similar in shape to our own, with the edges bevelled from the inside.
Drills and gravers of copper have also been found, with chisel-shaped edges or sharp points.
"It is not impossible," says Squier, "but, on the contrary, very probable, from a close inspection of the mound pottery, that the ancient people possessed the simple approximation toward the potter's wheel; and the polish which some of the finer vessels possess is due to other causes than vitrification."
Their sculptures show a considerable degree of progress. They consist of figures of birds, animals, reptiles, and the faces of men, carved from various kinds of stones, upon the bowls of pipes, upon toys, upon rings, and in distinct and separate figures. We give the opinions of those who have examined them.
Mr. Squier observes: "Various though not abundant specimens of their skill have been recovered, which in elegance of model, delicacy, and finish, as also in fineness of material, come fully up to the best Peruvian specimens, to which they bear, in many respects, a close resemblance. The bowls of most of the stone pipes are carved in miniature figures of animals, birds, reptiles, etc. All of them are executed with strict fidelity to nature, and with exquisite skill. Not only are the features of the objects faithfully represented, but their peculiarities and habits are in some degree exhibited…. The two heads here presented, intended to represent the eagle, are far superior in point of finish, spirit, and truthfulness, to any miniature carvings, ancient or modern, which have fallen under the notice of the authors. The peculiar defiant expression of the king of birds is admirably preserved in the carving, which in this respect, more than any other, displays the skill of the artist."
FROM THE MOUNDS OF THE OHIO VALLEY
Traces of cloth with "doubled and twisted fibre" have been found in the mounds; also matting; also shuttle-like tablets, used in weaving. There have also been found numerous musical pipes, with mouth-pieces and stops; lovers' pipes, curiously and delicately carved, reminding us of Bryant's lines—
"Till twilight came, and lovers walked and wooed
In a forgotten language; and old tunes,
From instruments of unremembered forms,
Gave the soft winds a voice."
There is evidence which goes to prove that the Mound Builders had relations with the people of a semi-tropical region in the direction of Atlantis. Among their sculptures, in Ohio, we find accurate representations of the lamantine, manatee, or sea-cow—found to-day on the shores of Florida, Brazil, and Central America—and of the toucan, a tropical and almost exclusively South American bird. Sea-shells from the Gulf, pearls from the Atlantic, and obsidian from Mexico, have also been found side by side in their mounds.