remains come from North Syria and Mesopotamia, leaving no doubt that the main stream of civilization in western Asia flowed then through that region, leaving all surrounding zones relatively unaffected.
The invention of pottery was certainly a major step in man's cultural progress. Earthenware vessels soon replaced gourds, skins and hollowed-out pieces of stone or wood, enabling man to live some distance from the source of his water supply and—even more important—to store for future use any surplus food, as well as seeds. The food gatherer of the nomadic stage, who had turned food producer in the agricultural stage, now became, in addition, food conserver. This gave him respite from the constant time-consuming search for sustenance, and the resulting leisure was essential to the furtherance of human progress.
The addition of pottery to man's household goods serves incidentally a most useful scientific purpose. Pottery is imperishable, though it may be smashed into innumerable sherds. Its make and decoration reflect the tastes and fashions of the age as women's clothing does in our day; its distribution affords the best index of early trade relations. Therefore its study opens up before the modern scholar one of the widest windows through which he can peep into the obscure realm of the past. Metallurgy provides a later window. With ceramics and metallurgy we pass from prehistory to protohistory.
The actual discovery of metal may have been made in western Asia soon after the invention of pottery, but the supremacy of its first important representative, copper, must have been delayed a thousand years or so. In Syria copper began to be more or less widely used around 4000 B.C., but it did not displace stone as the dominant material for tools and weapons till after 3000 B.C. This millennium, the fourth, may be designated the Chalcolithic (copper-stone) Age; in it copper was utilized by the most progressive communities, but flint remained the principal material. Traces of Chalco-
