The Indus weights
A single binary weight standard is used across a million square kilometres.
- When
- —
- Duration
- 700 years
- Known to
- ± 50 years
- Era
- Bronze Age, Holocene
Cubical chert weights from Indus sites follow a consistent system in ratios of 1, 2, 4, 8, 16 and upward, accurate to a fraction of a percent, and the same standard appears from Gujarat to Afghanistan and in Mesopotamian ports trading with them. Standardised measurement on this scale requires an authority to define and enforce it, which sits awkwardly with the absence of any obvious ruler.