xv) On leaving the Dome, the meridian takes a quick trip through the Blackwall tunnel (northbound southern tunnel built 1897, southbound northern tunnel opened 1967).
xvi) The meridian hits the north bank of the Thames at a brand new Barratt housing development in Blackwall. They've been good and not built a stack of one-bedroom shoeboxes on the line itself, but have instead planted a cobbled avenue of trees with yet another brass line down the middle. By the river there's a circle of concentric cobbles with a compass at the centre, pointing north. This is Virginia Quay, and a memorial a few yards to the east commemorates the departure point of the first permanent settlers to sail from England to the New World. King James I came down to Blackwall Steps to wave the settlers off, unaware of the dangers they would face across the Atlantic from malnutrition, Indian chiefs and being turned into Disney cartoon characters. The First Settlers' Monument, which was unveiled by the US Ambassador in 1928, reminds us how just successful their journey of colonisation turned out to be.
xvii) The meridian crosses the Docklands Light Railway at (or more precisely fractionally to the east of) East India station. There used to be a red line on the track marking zero degrees but it's not there now.
xviii) Next heading northwards: a security man sitting at a small barrier on Saffron Avenue, the A13, a downcast council estate at South Bromley (the last houses on the meridian for the next two miles), Poplar gasworks, Bow Creek.
