# London, piece by piece.

Fire and cholera, ice and fog, Persian journals and clay. Few works, each followed through to the end.

## Start here

- [The Great Fire of London, 1666, hour by hour on a map](https://mariuscomper.uk/londra-in-flacari/en/) — The 1666 fire spreads across today's City, day by day, from the diaries of Pepys and Evelyn. The losses were counted carefully; the dead were not.

## Masterpieces

4 works chosen for visual power, depth and finish: maps, atlases and stories showing everything this page can do.

- [The Thames frost fairs, 1608–1814, and why the river no longer freezes in London](https://mariuscomper.uk/tamisa-inghetata/en/) — Streets of booths, printing presses and taverns on the frozen river, from Evelyn's diary and the accounts of 1814. The cold that froze the Thames came back once, in 1963; with the old bridge gone, the river kept flowing.
- [The Broad Street pump, 1854: John Snow, cholera and the pump handle](https://mariuscomper.uk/pompa-din-broad-street/en/) — Soho, 1854: 616 cholera deaths around one pump. The handle came off when new cases had fallen from 143 a day to 12; the proof came from a clergyman who expected to prove Snow wrong.
- [A Persian in London, 1809-10 — the diary of Mirza Abul Hassan Khan](https://mariuscomper.uk/un-persan-la-londra/en/) — The diary of Mirza Abul Hassan Khan, the Persian envoy who conquered — and sharply judged — London in 1810.
- [The Clay That Never Cools](https://mariuscomper.uk/lutul-londrei/en/) — In 1900, the Tube was 14°C. After 125 years of braking, 500 GWh of annual heat have saturated the clay mantle, turning the earth into a 30°C radiator.

## All 6 works, newest first.

- [The Thames frost fairs, 1608–1814, and why the river no longer freezes in London](https://mariuscomper.uk/tamisa-inghetata/en/) — Streets of booths, printing presses and taverns on the frozen river, from Evelyn's diary and the accounts of 1814. The cold that froze the Thames came back once, in 1963; with the old bridge gone, the river kept flowing.
- [The Broad Street pump, 1854: John Snow, cholera and the pump handle](https://mariuscomper.uk/pompa-din-broad-street/en/) — Soho, 1854: 616 cholera deaths around one pump. The handle came off when new cases had fallen from 143 a day to 12; the proof came from a clergyman who expected to prove Snow wrong.
- [The Great Fire of London, 1666, hour by hour on a map](https://mariuscomper.uk/londra-in-flacari/en/) — The 1666 fire spreads across today's City, day by day, from the diaries of Pepys and Evelyn. The losses were counted carefully; the dead were not.
- [A Persian in London, 1809-10 — the diary of Mirza Abul Hassan Khan](https://mariuscomper.uk/un-persan-la-londra/en/) — The diary of Mirza Abul Hassan Khan, the Persian envoy who conquered — and sharply judged — London in 1810.
- [The same access points. The same 300 m threshold. Two results](https://mariuscomper.uk/aceeasi-londra-doua-distante/en/) — For the same official mapped access points in London, the result is 87.61% by straight line and 50.66% on the walking network.
- [The Clay That Never Cools](https://mariuscomper.uk/lutul-londrei/en/) — In 1900, the Tube was 14°C. After 125 years of braking, 500 GWh of annual heat have saturated the clay mantle, turning the earth into a 30°C radiator.

Updated: 2026-09-25