Passengers dressed in period costume enjoyed a trip on the restored 1898 Met Locomotive 1 today to mark the 150th anniversary of the London Underground.
The steam train headed to Moorgate underground station in the City of London after a journey from Olympia in west London.
London mayor Boris Johnson, who was among the passengers, described the journey as "romantic" and "pure Conan Doyle".
He said: "It was just extraordinary. We had steam coming in through the windows, huge thick clouds of white steam going past and then bits of soot coming through from the engine."
Johnson added: "It was fascinating, as the train started to go up from Kensington to Notting Hill you could feel the engine really strain, but as we levelled off it picked up a lot of speed. You could see how the Victorians were able to run a very timely service."