Wheal Busy Watt Engine
1777 · Watt Pumping Engine with Condenser · Work 329 of 1,871
A Boulton and Watt pumping engine installed at Wheal Busy near Chacewater: a tall masonry engine house with a thick bob wall, inside it a single upright cast cylinder standing on the floor with the separate condenser in its cistern of cold water beside it, the great wooden beam pivoted on top of the bob wall, its inner end over the cylinder and its outer end nodding out through the wall above the copper mine shaft, the pump rods hanging from the beam down the shaft.
- What it was used for
- A Boulton and Watt pumping engine with a separate condenser at Wheal Busy, also called Wheal Spirit, near Chacewater in Cornwall. According to Grace's Guide the mine had a major problem with water and installed the engine in late 1777 to dewater the lower levels. Cornwall Calling and the engine list of Explore Cornwall give a 30-inch cylinder for 1777. Erection was entrusted to Thomas Dudley, and Watt came down to Cornwall himself to see it completed. The Cornish Mining World Heritage Site contradicts itself on the year: one of its pages says September 1777, another 1778.
- What was new
- It was not Cornwall's first steam engine - according to Grace's Guide Newcomen engines had been at work at Chacewater since 1727, and the new engine clearly outperformed them. What was new was what the separate condenser could do: the same pumping on around 75 per cent less fuel, in a county where every ton of coal arrived by sea. The order of events needs keeping apart: the engine for Ting Tang was ordered first but arrived late, and the Wheal Busy engine was the first actually erected and at work. The barb is the accounting formula. The Cornish Mining World Heritage Site describes an arrangement returning to Boulton and Watt one third of the coal saving against an atmospheric engine of equal power - "an equation which was prone to dispute and interpretation". The better the engine, the larger the bill, and the comparison engine was never on the mine.