6/ In 1857 London was the site of a new innovation - postal codes.
The city was subdivided into 10 districts (EC (East Central), WC (West Central), N, NE, E, SE, S, SW, W, and NW)
Most of these codes are still used today, and the system was later expanded across the country.
Here's a street sign showing the postcode area in the no longer existent
"Borough of Finsbury"
7/ In 1884 an international convention met in Washington DC πΊπΈ, and the Greenwich meridian, passing through the Greenwich Observatory, was agreed to be the 0 line of longitude, the so-called "Prime Meridian"
https://en.wikipedia.org/wiki/Prime_meridian
The line was also used as the basis for timezone definition, hence the term "Greenwich Mean Time"
https://en.wikipedia.org/wiki/Greenwich_Mean_Time