150 Years Of The London 'Tube'

The London Underground's iconic sign appears in front of the Big Ben clock tower in central London.

A young visitor to the London Transport Museum runs in front of an old Underground map.

In this undated photo, workers extend the rail line using "cut and cover" construction, digging deep below the surface of London's Praed Street.

Workers on London’s Central Line during the construction of the British Museum Station in 1898. The station is no longer in use.

An illustration of the wooden "island" between the tracks at Stockwell Station

An undated lithograph of Baker Street Station...

...and a restored steam engine arriving at the same station in 2012 on a practice run ahead of the 150th anniversary celebrations.

An old-fashioned carriage pauses between test runs at Quorn Station.

A Metropolitan Railway guard, Eva Carver, poses in her guard's uniform (left and right).

A 1906 postcard of a train at Piccadilly Circus Station

A pocket-sized Underground map from 1933

An undated shot of Edgware Station on the Northern Line

The Acton Town Station in 1938

The restored interior of a 1938 carriage

Thousands of Londoners took shelter in the Underground during the Blitz, the German aerial campaign against Britain during World War II. Here people take cover in Aldwych Station, which was also used as a storehouse for artistic and historical treasures. 

A crowded platform at Piccadilly Circus Station, undated

Passengers wait at Baker Street Station.

Passengers go through an automatic ticket gate at the Seven Sisters Station in 1969.

Britain's Prince Charles (left) rides in the front of a carriage at the official opening of the Jubilee Line in 1979.

Piccadilly Line trains parked outside the Northfields depot in 2001.

Conservative Party leader David Cameron, who is now prime minister, travels on the Tube after a news conference in 2008.

A crowd of rush-hour commuters, 2008

The modern interior of Canary Wharf Station, 2009