Thinking further about viewtopic.php?p=113622#p113622, I reckon all of the Tube lines could be given more logical names:
Waterloo & City - the "Central line" because it's the only one entirely in central London.
Northern - the "Waterloo & City line" because one branch serves Waterloo and one serves the City.
Jubilee - the "Bakerloo line" because it connects Baker Street with Waterloo.
Bakerloo - the "Piccadilly line" because it serves Piccadilly Circus.
District - the "Victoria line" because it serves Victoria.
Metropolitan - the "Northern line" because it runs the furthest north.
Piccadilly - the "Jubilee line" because the Heathrow extension was opened by the late Queen in 1977, her Silver Jubilee year.
Central - the "Metropolitan line" because it reaches right across the metropolis.
Circle - the "Hammersmith & City line" because it begins in Hammersmith and then does a circuit through the City.
Hammersmith & City - the "District line" because it connects districts in west and east London.
Victoria - the "Circle line" because it takes a rather circuitous route from south to north London. (OK, that one doesn't really work
