Unravelling the duty : Lean's Engine Reporter and Cornish Steam Engineering

The development of the high pressure expansive engine marked a watershed in the evolution of steam power technology, allowing the attainment of major fuel economies. In Britain, Cornish engineers took the lead in the exploration of this specific technological trajectory. Notwithstanding its superior fuel efficiency was widely popularized, the high pressure expansive engine did not find widespread application in other steam-using regions (in particular in Lancashire), where the favourite option remained the Watt low pressure engine. In this paper, we provide a reassessment of the factors accounting for the precocious adoption of the high pressure steam engine in Cornwall and for its delayed fortune in the rest of Britain