Dun

The first name of the river
before planners and armourers took it over,

allowing the vowel's load to yield
like bursting banks. Dun Street, Dun Fields

are last remnants of this buried city,
now backs of derelict factories

where wind sniffs you like a hungry stray
and prostitutes pursue their trade.

Orwell's 'shallow river' was 'bright yellow
with some chemical or other'; he bestowed

on Sheffield the title: 'ugliest town
in the old world.' His sky was murky brown.

Now this stretch is broad again, salvage the name:
Dun makes me think how fish silver the gloom.