"Forgive my ignorance Bert, but who is Brunell"
Isombard Kingdom Brunel, English Engineer (1806-59)
Responsible for Clifton and Hungerford Suspension Bridges and the steamship The Great Britain, among other great feats of engineering.
Immortalised in a verse of Tom Lenihan's song about poitín (illicit Irish whiskey) 'Paddy's Panacea'.

Come guess me this riddle, what beats pipes and fiddle?
What's stronger than mustard and milder than cream?
What best whets your whistle, what's clearer than crystal?
What's sweeter than honey and stronger than steam?
What will make the dumb talk, what will make the lame walk?
What's the elixer of life and philosopher's stone?
What helped Mr Brunnell to dig the Thames Tunnel?
Sure wasn't it whiskey from old Inishowen?