UNIVERSAL ASTRONOMICAL RING
This beautiful universal astronomical ring is made of brass and etched with acid.
It is an Equatorial type sundial and is composed of a circle that represents the Earth’s equator and a central bar that represents the Earth’s axis.
The equatorial sundial reproduces the position of the Earth in a clearer way.
Conveniently tilted to counteract the Earth’s inclination, the shadow of the bar marks the hours on the inside of the circle.
This type of sundial adapts the systems of the ancient armillary spheres of Eratosthenes and Ptolemy.
HISTORY
Its invention has been attributed to the English mathematician William Oughtred (1574-1660), inventor of the slide rule, around the year 1600, becoming a very popular instrument throughout the 18th century. However, we already have evidence of the designs created by the Flemish scientific instrument maker Gemma Frisius in the mid-16th century and built by his relative Gualterius Arsenius and which they called annulus astronomicus
USE AND PRESENTATION
It is universal and can be used interchangeably in either hemisphere by changing the measurement scale.
It is presented in a wooden box decorated with astronomical motifs, perfect for making the perfect gift and is accompanied by a small leaflet with instructions for its use.
Measurements:
Diameter: 60 mm
Thickness: 3 mm
VAT INCLUDED
https://en.wikipedia.org/wiki/Sundial
