"Probably not. There is no trace of it in this early work. It is not until the historic age that we have the potter's wheel, the oldest and first mechanical device mentioned in history. Mexicans, Peruvians, Egyptians, Greeks, Assyrians, Romans, Gauls, Teutons all used it." "I have seen some of the old Mexican or Aztec pottery," declared Dr. Swift, "and it was very interesting. It was of reddish clay, and I was told it was much like the variety made in Peru. Not only were there roughly modeled dishes and jars in the collection, but also all sorts of strange clay idols. You see, instead of worshipping the gods of goodness, Theo, these early peoples thought they could propitiate the gods of evil if they worshipped them instead; accordingly they made all sorts of grotesque images, some of them very hideous. None of this clay work was glazed, of course, for at that time men had not yet discovered that they could put a glaze over the surface of objects and thus protect them and render them water-tight. It was a great pity that Cortez and his followers destroyed this early Mexican civilization, which was surprisingly advanced. "I suppose the Peruvians had also gone quite as far if not further than the Aztecs when in 1531 Pizarro invaded South America," rejoined Mr. Croyden. "They were making some very good pottery decorated in red, black, and brown; and they must have known how to bake it, or the colors in the design would not have lasted until now." Mr. Croyden rose to stamp out a spark that had snapped from the fireplace onto the fur rug at his feet. "Strange, isn't it, how much of our knowledge of the ancient races has come down to us through their clay work?" he reflected. "What should we have known of these western civilizations save through their handiwork? And when we travel across seas it is the same. Much of our acquaintance with Egyptian, Greek, and Roman life has been handed down to posterity through tiles and pottery which have served to record nations' customs and advancement. The march of the invading Roman armies, for example, can be traced by the fragments of pottery left behind them. These relics have been found in England, France, Germany, Italy, and Spain, and prove that very early the Romans made use of clay utensils for cooking their food. Even beneath the city of London old Roman furnaces for firing dishes have been discovered; and moreover, some of the very dishes themselves." Theo seemed astonished.