NOCTURNAL MEDIEVAL INSTRUMENT
The nocturnal medieval instrument is a device for finding out the time at night. Its operation is based on the fact that the stars appear to revolve around the North Star. It is, of course, the earth that is rotating while the North Star remains fixed, since it is located on the extension of the earth’s axis of rotation. Since the other stars seem to revolve around them (circumpolar stars), their position at all times tells us the time.
HISTORY
Sometimes called horologium nocturnum. This instrument has an astronomical correlation with the astrolabe and with sundials. Mentions of a specific instrument for measuring night time are not found until well into the Middle Ages.
The first known reference to the nocturlabium is a manuscript dated to the 12th century. Ramón Llull described on several occasions the use of a sphaera horarum noctis or nocturnum astrolabium. With Martín Cortés de Albacar’s book Arte de Navegar, published in 1551, the instrument gained greater popularity.
ITS USE
Knowing the time was very important for sailors at sea. It was necessary to know the precise time, using tide tables, to be able to safely enter ports and also to regulate work shifts.
With the nocturlnal, navigators were able to know the time at night, as long as the sky was clear. The problem arose when the sky was cloudy in which the stars could not be observed and then they were forced to use hourglasses, until in the mid-18th century chronometers appeared and night timers fell into disuse.
The nocturnal is actually a very simple analog computer. Compared to other instruments that require mathematical tables and trigonometry, it is very easy to use.
OUR NOCTURNAL
Our nocturnal is prepared to work with three constellations: Ursa Major, Ursa Minor and Cassiopeia.
It is made of metal plated in old brass. The support is made of wood and is presented in a beautiful case, perfect for making an unforgettable gift. It is accompanied by a booklet with all the historical reviews and instructions for its use.
Measures:
Height (including throne) 13 cm
Diameter: 9.5cm
thickness: 0.5cm
VAT INCLUDED
https://en.wikipedia.org/wiki/Nocturnal_(instrument)
