Clay tablets were not the only means of keeping records during the Uruk period. City administrators also used hollow clay balls or “bullae.” Bullae have been found at sites in Iran, Mesopotamia, and Syria but the majority come from Susa II and III. The clay spheroids held tokens made of clay or stone, each representing a specific quantity and/or thing. The clay bullae were once considered to be the precursors of tablets but it now appears as though the two were largely contemporaneous. The use of clay bullae as record-keeping devices persisted well into the Late Bronze period at places such as Nuzi, in northern Iraq, where large numbers of bullae have also been found.

Left: ARC/Oriental Institute Museum

S. Lieberman notes that clay bullae were better suited than tablets for maintaining running tallies. If a royal steward wished to discover how many ewes had given birth that year, he had only to find the jar which tracked this particular statistic (ewes that gave birth) and count the number of pebbles contained therein. It was easier to keep track of this type of information with pebbles collected in a jar than to keep a running tally of it on a clay tablet. A receipt for the sale of animals may have been recorded by removing pebbles from the jar and placing them inside a clay bullae. The outside of the bullae was imprinted with the owner’s seal and placed on deposit as a “proof of purchase.”

It is interesting to note that this method of accounting would remain in use in one form or another until the Roman period, and even into the Medieval period with the so-called “tally sticks.” The method utilizes a binary system (the pebble is in the jar or out of it) that works on the same principle as computer code. Indeed, the English word “compute” is actually derived from the Latin word calculi which means “pebble.”¹Lieberman 1980, 342 The difference between clay bullae and your smartphone is that the latter contains a lot more pebbles!