Tide Calculator

Circular brass tidal calculator.
The outer circle is divided into 2 x 12 hours and compass directions.
The middle circle has a pointer for the Sun and is marked for the age of the Moon and compass points.
The inner circle has a pointer for the Moon and is marked with compass points.

Object Details

ID: AST0394
Type: Tide Calculator
Display location: Display - ROG
Creator: Unknown
Date made: 1530-80; 17th century
Credit: National Maritime Museum, Greenwich, London, Caird Collection
Measurements: Overall: 3 x 135 x 124 x 124 mm