Pocket Nocturnal and Tide Computer

Fully Functional Brass Nocturnal Star Dial and Tide Calculator

History and Principles of the Nocturnal

The nocturnal, also known as a star dial, was an indispensable navigation tool, particularly during the Renaissance and early modern period. In times before reliable and accurate mechanical watches existed, sailors and astronomers needed to know the exact time even at night to calculate their position correctly. The principle of the nocturnal relies on observing the rotation of specific fixed stars (most commonly Polaris in the Northern Hemisphere and the Southern Cross in the Southern Hemisphere) in relation to the time of year. You sight the reference star through the central hole and align the movable arm with another designated star (such as Kochab in the Little Dipper). The dial on the instrument will then reveal the current time to you. The back of this model is additionally equipped with a historical dial for calculating high and low tide times at your location.

Caring for Your Brass Navigation Instrument

The instrument is crafted from high-quality polished brass. To maintain its dazzling shine and prevent it from aging due to oxidation (tarnishing or developing a green patina), we recommend occasionally polishing it with special cloths or pastes designed for non-ferrous metals. Avoid contact with harsh chemicals and damp environments. A soft microfibre cloth is usually sufficient for regular cleaning. Never bend the delicate moving arms, especially the fold-out pointer, with force, as this could irreversibly damage the axle of the mechanism or snap the metal. Avoid dropping it on hard surfaces, which could compromise the smooth functionality of the rotating discs.

Technical Specifications of the Star Dial

For the completely safe and stylish carrying of this wonderful historical instrument, we recommend purchasing a high-quality leather pouch from our range of belt accessories.