The Nocturnal Tide Nocturnal Abacus is a unique scientific instrument, through the observation of the Pole Star and the circumpolar stars is a Sundial, as it allows us to find out the solar time at night.
This piece is perfect to have in any collection, office or cabinet of curiosities, it is a replica of a Nocturnal and Tide Abacus from 1570, signed by Humphrey Cole "first maker of English scientific instruments" which is in the British Museum, London. One of its faces is a Nocturnal (Sundial) and the other is a Tide Abacus. (Nautical instrument)
The nocturlab or star clock is an artifact that serves to obtain the time at night using the fixed stars in the sky. The abacus or tide computer is used to calculate the times of the tides, vital for navigation, ports and fishing.