19th Century pox: References

1. London’s population growth during the 19th century:

During the 19th century, London grew enormously to become a global city of immense importance. It was the largest city in the world from about 1825, the world’s largest port…

https://en.wikipedia.org/wiki/19th-century_London#:~:text=During%20the%2019th%20century%2C%20London%20was%20transformed%20into%20the%20world’s,estimated%20at%206.292%20million%20people.