|July 1907: St Pancras Railway Station. (Topical Press Agency / Getty Images)|
The cold weather preceding and during the smog meant that Londoners were burning more coal than usual to keep warm. Post-war domestic coal tended to be of a relatively low-grade, sulfurous variety (economic necessity meant that better-quality “hard” coals tended to be exported), which increased the amount of sulfur dioxide in the smoke. There were also numerous coal-fired power stations in the Greater London area, including Fulham, Battersea, Bankside, and Kingston upon Thames, all of which added to the pollution.