Victorian illustration to download showing a picture of a diving bell used in the construction of the Thames Tunnel (built by Marc and Isambard Kingdom Brunel, 1824-43) being lowered from a boat. This was the first tunnel in the world to be built under a river. Intended for wheeled vehicles, it was at first only used by pedestrians; in 1869 it became a railway tunnel, then part of the London Underground network, and in 2010 became part of the London Overground train system.