He'd find evidence of lung trouble in a copper-bottomed boiler if it wheezed letting off steam.
It's real, copper-bottomed English; you see it on all the old-time wayside hostelries over there.
His copper-bottomed ships came up with and captured six of the enemy, five of which were English prizes.
Genuine; authentic: a copper-bottomed scoundrel
[1890+; fr the covering of a ship's bottom with copper plates to frustrate the shipworm]