This is a lost artifact, known only through ancient stories of long-deceased ancestors, and has not been discovered in Ur. Masha, the daughter of Anton and greatest scholar of the laws of Friendly in the forest, used to claim that her superlative powers of memory were attributable to her diet of nothing but eggs, using a cedar plank for a flannel, and never forgetting to place her worn black socks on the special hooked sock-holder she had built herself. She was also a bit mad.