The pottery of the earliest Theban dynasties which I have collected at El Khozam and Gebeleyn is more carefully wrought than the pottery of the Memphite period. It may be classified under two heads. The first comprises plain, smooth-bodied vases, black below and dark red above. On examining this ware where broken, we see that the colour was mixed with the clay during the kneading, and that the two zones were separately prepared, roughly joined, and then uniformly glazed. The second class comprises vases of various and sometimes eccentric forms, moulded of red or tawny clay.
Glass was known to the Egyptians from the remotest period, and glass- blowing is represented in tombs which date from some thousands of years before our era (fig. 224). The craftsman, seated before the furnace, takes up a small quantity of the fused substance upon the end of his cane and blows it circumspectly, taking care to keep it in contact with the flame, so that it may not harden during the operation. Chemical analysis shows the constituent parts of Egyptian glass to have been nearly identical with our own; but it contains, besides silex, lime, alumina, and soda, a relatively large proportion of extraneous substances, as copper, oxide of iron, and oxide of manganese, which they apparently knew not how to eliminate. Hence Egyptian glass is scarcely ever colourless, but inclines to an uncertain shade of yellow or green. Some ill-made pieces are so utterly decomposed that they flake away, or fall to iridescent dust, at the lightest touch.
