An Occasional Half

A pint stood on a bar for fifty years.
Flock moulded. Fly-posters sealed the windows.
Hurry up please it's time! collapsed to a soft roar
of traffic and building work. The ale lay down
its sediment (like the Thames that must still flow
regardless streets away), a ring of scum
now halfway down the glass: the angels' share.

Returning from the Gents five decades in
I've found my beer-mat note - I'VE SPAT IN THIS -
has an addendum: SO HAVE WE. And so,
my brown-and-mild minesweeping seraphim,
let's have another half in this one. Cheers!