Definition:Centimetre/Historical Note

Historical Note on Centimetre
The centimetre was initially defined as:
 * $10^{-9}$ the distance from the Earth's equator to the North Pole at sea level

that is:
 * $\frac 1 {100}$ the length of a metre.

Its importance as one of the base units of the CGS system has waned, as the MKS system has supplanted it in importance.