Before revision: Lead, a by-product of the ancient silver smelting process, was produced in the Roman Empire with an estimated peak production of 80,000 metric tons per year – a truly industrial scale.
After revision: Manufacture of pipes upUninscribed lead pipe with a folded seam, at the Roman thermae of Bath, EnglandLead, a by-product of the ancient silver smelting process, was produced in the Roman Empire with an estimated peak production of 80,000 metric tons per year – a truly industrial scale.