3/ Originally, the London Underground used a geographical map, not the topological style that Beck invented we are all used to.
There used to be a different pamphlet for each train line, and it was only in 1908 that the network’s several train lines were first plotted onto a single map.
As the network grew in scope and complexity, geographically correct maps became problematic.
4/ In 1931, Beck presented a prototype of a new Underground map.
Interestingly, his idea was originally turned down.
It was only in 1933 that the map was adopted en-masse, with a first print of about 700,000 copies.