Calotype from the collection of William Henry Fox Talbot (1800-1877). Talbot invented the negative/positive proces for producing photographs between 1835-39. Any number of prints could be made from the same shot by transferring the negative image on to special paper to make a positive print; these prints were called calotypes. Isambard Kingdom Brunel's (1803-1859) suspension pedestrian footbridge opened in 1845. It spanned the River Thames from The Embankment to Lambeth and linked London's West End with the South Bank. It was replaced in 1864 by a railway bridge with a pedestrian walkway. Two new footbridges, built on either side of the 1864 bridge and costing £40 million, opened in 2002.
© National Museum of Science & Media / Science & Society Picture Library