"Nick P" wrote

I'd also look at odd stubs where the lines went further to more useful
places. The keeping of Mill Hill East seems odd but there was a barracks
nearby.
The 1935 plan wasto extend the Northern Line from Archway to East Finchley,
then for LT to take over, as part of the Northern Line, Finsbury Park to
East Finchley, Highgate to Alexandra Palace, East Finchley to High Barnet
and to Edgware via Mill Hill East, and to extend out beyond Edgware to
Bushey Heath. The Northern Line had reached East Finchley before the
outbreak of WW2 and work on to High Barnet was ell advanced, so was
completed. The Finchley to Edgware service was suspended to facilitate
doubling, but, as you say because of the barracks, a single line was
electrified to Mill Hill East. All the rest of the project was suspended and
eventually abandoned. The line beyond Mill Hill East to Edgware remained
open for freight until 1964 (freight trains coming from Finsbury Park via
Highgate).

Peter