This was used for example in Persia to ensure fair irrigation practices. The passage of time was observed by counting how many times the bowl overflowed and its content had to be poured back in the larger pot. These existed back in the 16th century BC. The oldest water clocks simply consisted of a pierced bowl placed in a larger pot filled with water (see left image, Persian artefact from 400 BC). Image taken from en. (photo Denise Schmandt-Besserat)Ī water clock (or clepsydra) is an instrument where time is measured by regulating a flow of liquid. Denise Schmandt-Besserat (1996) How Writing Came About. Sources: Denise Schmandt-Besserat (1999) Tokens: The Cognitive Significance. ' Clay tokens suggest that physical objects were used to externalize information, support visual thinking and enhance cognition way before paper and writing were invented. 19) No doubt patterning, the presentation of data in a particular configuration, was developed to highlight special items (Luria 1976. The token system thus encouraged manipulating data by abstracting all possible variables. For instance, the tokens could be ordered in special columns according to types of merchandise, entries and expenditures donors or recipients.

According to an eminent archaeologist (Schmandt-Besserat, 1999): 'Whereas words consist of immaterial sounds, the tokens were concrete, solid, tangible artifacts, which could be handled, arranged and rearranged at will. The earliest data visualizations were likely physical: built by arranging stones or pebbles, and later, clay tokens.

J.u.l.i.a. among the stars artifacts