Airy's Meridian Line -- Royal Observatory, Greenwich, London, UK
N 51° 28.673 W 000° 00.088
30U E 708215 N 5707233
Royal Astronomer George Biddell Airy's Meridian Line, better known as The Prime Meridian of the World
Waymark Code: WMT40P
Location: London, United Kingdom
Date Posted: 09/21/2016
Views: 3
This brushed metal historical marker plaque is one of several in the garden of Flamsteel House at the Royal Observatory. The markers relate the history of each meridian marked by earlier Astronomers Royal, leading up to the adoption of Airy's as the Prime Meridian of the World.
The building ahead of the marker contains Airy's Telescope, which is still used today (with a laser enhancement) to determine Greenwich Mean Time at the Prime Meridian.
The marker reads as follows:
"AIRY’S MERIDIAN LINE
George Biddell Airy, seventh Astronomer Royal, commissioned the enormous telescope that still defines the prime Meridian and is situated in the building ahead of you. Observations made here were used by cartographers surveyors navigators and astronomers. By 1884, most ships were using charts based on this Meridian line. Since that year and has been the baseline for world time.
|<- You are now standing on the Prime Meridian of the World, as
| defined by Airy's telescope and agreed by international
| convention in 1884.
Astronomers worked in pairs on the Airy transit circle: one looked through the eyepiece while the other observed the microscope readings on the stone pier."
Type of Historic Marker: Interpretive sign
Historical Marker Issuing Authority: Royal Museums Greenwich
Age/Event Date: 01/01/1884
Related Website: [Web Link]
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