Miniature star clock - nocturnal H84 - keychain

Miniature star clock - nocturnal.
The device is a miniature of an instrument built by H. Cole in 1570, the original of which is kept at the British Museum in London.
It enables time to be determined at night using the stars.
Diameter 50 mm, depth 6 mm, weight 60 g
Gift packaging: beautiful gift box with insert
Made of zinc alloy and brass, lacquered using a technique from several hundred years ago.

Nocturnal - star clock is a beautiful instrument that enables time to be determined at night using the position of the stars. The device consists of a fixed dial divided into months, with all days of the year marked, a movable dial indicating hours on a 1-12 scale topped with an indicator - a moon face, and a long movable indicator arm. In the center of the device there is a sight through which we locate the Pole Star (North Star) - a fixed point around which other constellations revolve, e.g. the Big Dipper. And it is precisely because the position of the North Star is fixed that we can relate to it the changing position of other constellations over time. Our device - a replica of the 1570 instrument - is dedicated to the star Kochab in the constellation of the Little Dipper. But most often, and probably most simply, the indicator arm is set to the rear axis of the Big Dipper and the movable dial to the current date. This allows the current sidereal time to be read. The device is universal - it works at all longitudes in the Northern Hemisphere. Please remember that sidereal time does not necessarily correspond to official time. Great fun!

On the other side of the device there is a diagram showing how to use the device.

A wonderful gift for a sailor, navigator, fisherman, or astronomy enthusiast.

Instructions for use in the following languages: English, French, Italian, and Spanish.

A product of the Spanish company Hemisferium.

The set includes an attractive decorative box with an insert on which the device rests.