"Not among the least interesting and remarkable relics," continues the same author, "obtained from the mounds are the stone tubes. They are all carved from fine-grained materials, capable of receiving a polish, and being made ornamental as well as useful. The finest specimen yet discovered, and which can scarcely be surpassed in the delicacy of its workmanship, was found in a mound in the immediate vicinity of Chillicothe. It is composed of a compact variety of slate. This stone cuts with great clearness, and receives a fine though not glaring polish. The tube under notice is thirteen inches long by one and one-tenth in diameter; one end swells slightly, and the other terminates in a broad, flattened, triangular mouth-piece of fine proportions, which is carved with mathematical precision. It is drilled throughout; the bore is seven-tenths of an inch in diameter at the cylindrical end of the tube, and retains that calibre until it reaches the point where the cylinder subsides into the mouth-piece, when it contracts gradually to one-tenth of an inch. The inner surface of the tube is perfectly smooth till within a short distance of the point of contraction. For the remaining distance the circular striæ, formed by the drill in boring, are distinctly marked. The carving upon it is very fine." That they possessed saws is proved by the fact that on some fossil teeth found in one of the mounds the striæ of the teeth of the saw could be distinctly perceived. 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.