The Meridian Line
In the north Cloister is a Meridian Line.
It is made up of three parts: a covered cloister window with a small hole in it, and numbered division lines on the wall and floor.
History
An accurate tool
In the 1820s the Dean and Chapter decided that, like many cathedrals in Europe, Durham should have a Meridian Line. They authorized the Rev. J. Carr and W.L. Wharton, Esq. to engrave a meridian line upon the floor and wall of the north cloister. This was a time before reliable clocks were widely available, and the most accurate way of telling the time was by using the sun. The best type of sundial was a meridian line.
A meridian line could be set up very precisely by measuring where a directed beam of light fell at midday on the longest day of the year (around 21 June), when the sun is at its highest in the sky, and on the shortest day of the year (around 21 December), when the sun is lowest.
The beam of light moves between these two points during the rest of the year, so the line can be used all year round to accurately tell the time, and people could set their own watches and clocks by it.
To make extra sure that the Durham meridian line was accurate, Rev. Carr and Mr Wharton took measurements on the longest and shortest days for several years before they carved the line in 1829.
Did you know?
- The Meridian Line was carved in 1829, before Greenwich Mean Time (GMT) became the standard across the whole country.
- Our meridian line was set to show noon ‘Durham Mean Time’, which is about 6 minutes 16 seconds ahead of GMT.
- The sun's light falls on the floor marks on the longest day of the year and on the wall marks at the shortest day.
- The cloister window beside the marks was partially blocked with just a small hole left to focus the sun's light into a beam.
- To allow the Meridian Line to work properly, part of the stone parapet on the roof opposite it had to be removed, as it blocked the sun's light on the shortest day!
Thoughts and reflections
"This meridian line having been constructed with much care, may probably be found useful to any person...in the neighbourhood of Durham;"
Durham County Advertiser, 4 July 1829
Follow the guided tour
You’re in: The Cloister You’re at: The Meridian Line Next stop: The Laver Bowl
- Look across to the middle of the grassed area in the centre of the Cloister
- You will see a large stone bowl
- This is the Laver Bowl