In August 1854, a lethal outbreak of cholera hit Broad Street, in Soho – now Broadwick Street. More than 500 people died from the disease.
Along came the brilliant Dr John Snow (1813-58) – who gave his name to the pub in the background of this picture. He realised that the cases were clustered around the water pump on this site. And then he came up with the simplest, most inspired solution – remove the handle from the pump, so that the pump was disabled, and that people would use other – healthy – pumps. It later transpired that the Broad Street pump had been installed next to a cesspit, itself infected with cholera by a baby's cloth nappy.
Snow not only stopped the epidemic. He also successfully disproved the pre-existing 'miasma' theory of cholera – that it was spread through the air, rather than by germs.
This week, Westminster City Council installed a new copy of the pump – a worthy memorial to the great Dr Snow. You'll note that it doesn't have a handle.