A fine example of Beck's iconic map of the London Underground System.

The map was designed by the 29 year-old engineer Harry Beck. Abandoning the restrictions of a geographically correct layout, the map actually constitutes a diagram of the network, showing relationships rather than distances to scale. By using only verticals, horizontals and diagonals, and adopting a clear colour scheme, Beck created a design classic, both easy to use and aesthetically appealing. After the positive public response to the limited trial run issued in 1932, the design was formally adopted in 1933, becoming an essential part of London Transport's campaign to project itself as a modern, rational and efficient system. The design remains in use to this day, having become essential to the comprehensibility of complex transport networks all over the world.

The present example is the first state of the map issued in January of 1933: the interchange stations are marked with a diamond; the Piccadilly Line is under construction between Enfield West and Cockfosters, due to be opened mid-summer of 1933.