UK ~ Royal Museum - Greenwich - London - UNESCO ~

... Interesting night view of the "Prime" or "Greenwich" meridian and the Airy´d Transit Circle (telescope)... the Prime Meridian was defined by this legendary telescope... the line in the Royal Observatory represents the historic Prime Meridian of the World - Longitude 0º... every place on Earth was measured in terms of its distance east or west from this line... the line itself divided the eastern and western hemispheres...  if you stand on the world-famous Prime Meridian Line with one foot on one side and the other on the left, you are perfectly in the middle of east and west, according to the prime meridian line...(✉️ on its way) Thanks a lot Paul!【ツ】

The prime meridian is arbitrary, meaning it could be chosen to be anywhere. Any line of longitude (a meridian) can serve as the 0° longitude line. However, there is an international agreement that the meridian that runs through Greenwich, England, is considered the official prime meridian.

The Airy Transit Circle telescope was designed by English mathematician and astronomer George Biddell Airy. The first observation was taken on 4 January 1851 and it remained in continual use until 1938 – though the last ever observation was taken in 1954. The transit circle still sits in its original mounting, in the Transit Circle Room at the Royal Observatory.

The Maritime Greenwich UNESCO site comprises the historic town centre, Royal Park and related institutional buildings, and became a  WHS site in 1997.

© National Maritime Museum, Greenwich, London 

Stamp:

Oak Tree - Country Definitives (England)

(Issued 11-08-2020)