One of a series of photographs by Henry Flather showing the construction, undertaken between 1866 and 1870, of the Metropolitan District Railway's (MDR) underground lines between Paddington and Blackfriars via Kensington. The line laid by the MDR from the 1860s onwards was designed to provide a rail connection for travellers between London's mainline railway terminals, situated in a ring around the city centre. It now forms part of the existing District and Circle Lines on the London Underground. The line between Westminster and Blackfriars was opened on 30 May 1870. As shown here, the construction work taking place beside the newly opened Blackfriars Bridge (1869) attracted many onlookers.
© Science Museum / Science & Society Picture Library