This horizontal condensing engine was made in 1864 by Earnshaw and Holt in Rochdale, and used at Durn Mill in nearby Littleborough. It provided 250 horse power to the mill. The engine worked until 1946, and only ever had one part replaced during its 80-year working life (the governor, which was replaced with the Lumbs governor seen here in 1921).
Horizontal condensing engines like this were much more efficient than earlier beam engines, and could withstand higher pressure, making them more powerful. The wooden cladding on the cylinder provides insulation, stopping the heat from escaping.
This engine was used to make tartan at Durn Mill. Tartan was a popular fabric for clothes and home goods in the Victorian era, and factories like Durn produced both traditional and modern patterns. Durn was an integrated mill which both spun and wove wool.