Tidal Abacus Keychain

Tidal Abacus Keychain

Regular price
Sold out
Sale price
€21,00
Tax included. Shipping calculated at checkout.
Quantity must be 1 or more

It is a replica of the Nocturlabio and Tidal Abacus from 1570, signed by Humphrey Cole. This instrument is currently in the British Museum, London. One of its faces is this Abacus or Tidal Computer and the other is a Night-lip.

The abacus or tidal computer is used to calculate the times of the tides. The tides with their constant change in the level of the waters have effects of great importance for navigation, for ports and for fishing. 

Diameter: 50mm 
Thickness: 6mm
English en