Nocturnal (instrument) - Wikipedia
网页A nocturnal is an instrument used to determine the local time based on the position of a star in the night sky relative to the pole star. As a result of the Earth's rotation, any fixed star makes a full revolution around the pole star in 23 hours and 56 minutes and therefore can be used as an hour hand.
The Sundial Primer - The Nocturnal
网页The nocturnal is an instrument developed for use by sailors who noticed that the northern stars appeared to rotate around the Pole Star. They would memorize the positions of some of these stars at various times of the night at the various seasons. Figure 1 illustrates the three parts that make up the nocturnal.
What is a nocturnal? - Royal Museums Greenwich
网页2023年10月30日 · For centuries, people used an instrument called a ‘nocturnal’ or ‘nocturlabe’ to tell the time based on the motion/movement of the stars. Here at the Royal Observatory Greenwich we have a fantastic collection of nocturnals that you can see online and in-person in our displays.
Nocturnal - Astrolabe
网页A nocturnal is an instrument used to determine the time during the night, based on the position of a certain star in the night sky. A nocturnal is typically a navigational instrument. Knowing the time is important in piloting for calculating tides and some nocturnals incorporate tide charts for important ports.
Nocturnal (instrument) - Wikiwand
网页A nocturnal is an instrument used to determine the local time based on the position of a star in the night sky relative to the pole star. As a result of the Earth's rotation, any fixed star makes a full revolution around the pole star in 23 hours and 56 minutes and therefore can be used as an hour hand.
BBC - A History of the World - Object : Nocturnal or Nightdial
网页The nocturnal is a navigational instrument that was first invented in the 16th Century. By focusing on the stars it can estimate the time to within 10-15 minutes. The outer edge of the...
How it works Nocturnal – Kala Sundial
网页INSTRUCTIONS FOR NOCTURNAL. WHERE TO HOLD INSTRUMENT. Hold the instrument on the small handle vertically and downward - which is part of the outer disk featuring a 365 day date scale. SET THE DATE. Select the right date by aligning the pointer, part of the inner disk and decorated with a moon …
Nocturnal - History of Science Museum, Oxford
网页The nocturnal is an instrument developed in the 16th century for determining time at night. It utilizes the Pole star (Polaris) and either the 'pointers' of Ursa Major or the 'guards' of Ursa Minor. A handheld instrument, it was often made of …
Nocturnal - Royal Museums Greenwich
网页Nocturnal This is a typical example of a 17th-century English nocturnal, an instrument designed for telling the time at night. It is made of boxwood with a heart shape cut out of the handle, which also has the words 'BOTH BEARS' stamped into it.
nocturnal; horizontal dial; sundial; moondial; compass-dial; instrument …
网页This brass instrument consists of a nocturnal and a horizontal dial for a latitude of circa 49°. It is comprised of a circular plate with several volvelles, to which a handle with compass is attached. The FRONT is laid out for a horizontal dial with the folding gnomon set for a latitude of circa 49°.
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