Overseer
Western Thunderer
I think it was architecture. Called an open-bed or broken-base pediment, used to emphasise a gable when a full pediment would be too much. Looks like the details were removed when they decayed rather than being repaired.Not sure what the blob was but it looks like it was timber, so the rotted away idea would fit. Looks an awkward lump whatever it was.
This is an example of a pumping station in Ware, photo from 'Brick Building in Britain' by RW Brunskill.