Nocturnal or Nightdial

Contributed by Ballymoney Museum

Nocturnal or Nightdial

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 instrument is divided into days and months. When this is set, the user holds it up at arm's length so that the North Star shows through the central brass hole. The long arm is then aligned with the star constellation known as The Great Bear. The inner dial is marked in hours and minutes. The time can then be read from where the arm crosses the inner dial. Nocturnals were often favoured by mariners. Some rural communities continued to use them until the early 19th century to set their town clocks.

Only two wooden nocturnals are known to exist in Ireland. The other is in the National Museum of Ireland, Dublin.

This example was donated to Ballymoney Museum in 1873. It is inscribed 'A.R. Kyle 1781'. This is the original owner's name. The maker's name is unknown. For more information on astronomical and navigational instruments, visit the National Maritime Museum website.

Comments are closed for this object

Most of the content on A History of the World is created by the contributors, who are the museums and members of the public. The views expressed are theirs and unless specifically stated are not those of the BBC or the British Museum. The BBC is not responsible for the content of any external sites referenced. In the event that you consider anything on this page to be in breach of the site’s House Rules please Flag This Object.

About this object

Click a button to explore other objects in the timeline

Culture
Period

1781

Theme
Size
Colour
Material

View more objects from people in Northern Ireland.

Find out more

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.