Map; Diagrammatic historical map of Metropolitan line covering period 1868 to 1961, issued by London Transport, 1961

A well-designed diagram of the Metropolitan Line, describing its development between 1868 and 1961. The diagram and text is printed in purple, and is hand-drawn and lettered. The railway is represented by twin vertical lines that extend down the sheet, with Amersham at the top, Baker Street at the bottom and the intermediate stations shown along the route using four symbols, explained by the key. The branches to Chesham, Watford, Uxbridge and Stanmore are drawn, as is the Met & Circle line at Baker Street and the parallel Great Central railway. On the right of the diagram, brief historical facts are noted next to the relevant station or branch. On the left, electrification dates, four-tracking dates, opening dates and mileage from Baker Street Junction are recorded.