Ridley's Meridian Project

Roughly speaking this project is to draw a yellow line down the Greenwich meridian. Starting at Peacehaven and working north, hopefully through the whole of Sussex.

Photos have been taken from exactly on the Prime meridian line and doctored with a yellow smudge to show it's path accross the landscape.

The images are also plotted on the geograph website but without the yellow smudge.





The meridian shown in these images is mostly the Prime meridian of the world also known as the Airy Meridian which passes straight through the Greenwich observatory. At these latitudes the Airy meridian is a good 100m west of the WGS-84 prime meridian which is used by satellite navigation devices and google earth. See this article. Just to confuse things further most monuments and markers in the UK are on the OSGB36 Bradley Meridian, (including the most southerly one on the cliff top in Peacehaven). The Bradley meridian is still used on Ordnance Survey maps. When the Prime Meridian effectively moved 6 metres east in 1851 the Ordnance Survey didn't bother to change their maps. Some UK markers are on the more recent Airy Meridian and some are even on WGS-84, though this is rare. Where monuments are on the Bradley meridian I have usually shown both Bradley and Airy meridians. The Airy Meridian is always shown as a Yellow line and the Bradley as a green line.

Meridian links

Monument catalogue East meets West


Royal observatory

Geograph map

coordinate conversion

This picture shows that the Peacehaven monument is on the Bradley meridian. The photo is taken standing on the Prime Airy Meridian which is 6 metres East of the monument.

Most of the first photos I took in Peacehaven were taken on the Bradley Meridian. Both meridian markers in Peacehaven, (here and in Peacehaven school), are on the Bradley Meridian. This threw me a bit. North of Peacehaven the photos are virtually all on the Airy meridian.

The Meridian is now clearly visible as a continuous line of dots on the Geograph website maps as it stretches from Peacehaven to Lewes. Every spot is a photo.