Railway line.
	The good, the evil, the famous: our life-lines tangle here.
	How many millions have passed through?

Imagine that, wherever you went, a faint thread spooled out behind
you, recording your path. Heavily-trafficked places would end up with
a thick carpet of these threads, woven into a bizarre carpet. But the
one place where people's life-lines were densest would be along the
railway tracks; while a major road has many lanes to spread the
traffic and the cars can move about within the lanes to a certain
degree, the rail network is narrower.

Standing looking at a railway bridge, as a clearly-defined region of
space, I wonder how many people have passed through it in the hundred
or so years of its existence; how many lives are entangled in that
archway of brick.