wrote:

I have never seen a loop on a Quail map at Euston.

I don't think I have ever seen it (never noticed it when passing by) but
there is something on this track diagram:
http://www.chesapeake.net/~cambronj/...s/northern.jpg
And there is a connection to the Piccadilly Line there too. I don't know
how far it is from the Euston platforms though, a connection to the
Piccadilly Line seems to inply that it may be near King's Cross.

Also, look at the Layout and Connection sections of Clive's page about
the Northern Line:
http://www.davros.org/rail/culg/northern.html

--
Olof Lagerkvist
ICQ: 724451
Web: http://here.is/olof