As schoolboys love to fill
the science corridors
with rotten wafts of sulphides,
the agriculture lads
on Primrose Hill wallowed
in the reek of silage
intense as cow dung cubed,
but strongest when inverted
cold slides down the slopes
to frost both ground and roofs
and freeze breath-vapour
to snot-like icicles,
and sneakiest when snuck
by night into the heating
ducts of student dorms.