Smeaton’s Long Benton Engine

Northumberland, 1772

John Smeaton never invented an engine; he measured them. Armed with a test programme and a model boiler, he found the proportions the millwrights had been guessing at and nearly doubled the duty of the atmospheric engine without adding a single new part. Long Benton was his showpiece. The original bore was fifty-two inches — past the Works’ largest pattern — so our specimen is set to twenty-eight and the same discipline.

Smeaton logged 9.45 millions of duty from the original — the best figure the old engine ever gave.

On our bed: seven horses, eight and a half thousand gallons an hour, and near five millions of duty — the measurer’s margin over Dudley, plain on the gauges.

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