A Cornish Pumping Engine

after Taylor’s practice, Gwennap, 1840

The duty champions of the world: strong steam cut off at a fifth of the stroke, expanded down onto a Watt vacuum, in engines the size of chapels kept by engineers who published their coal bills monthly. Taylor’s 85-inch at United Mines logged the figures every rival chased. The Works’ patterns stop at thirty-two inches, so our specimen keeps the practice, not the acreage.

The great Cornish engines logged over 100 millions of duty — treble anything the Watt patent ever managed.

On our bed the practice returns near seventy millions of duty — half again anything else in the cabinet, on the leanest fire in it.

One of the cabinet’s specimens, each ready for the test bed.