Editing Compound steam engine (section)

===Mill engines===
{{Main|Stationary steam engine}}
[[File:Steam engine at Craven Mills - geograph.org.uk - 388255.jpg|thumb|right|A Marchent & Morley horizontal tandem compound engine built 1914, at Craven Mills, Cole. The air pump and jet condenser are nearest with the LP cylinder beyond. It is fitted with Morley's patent piston drop valves]]
Though the first mills were driven by [[water power]], once steam engines were adopted the manufacturer no longer needed to site the mills by running water. Cotton spinning required ever larger mills to fulfil the demand, and this drove the owners to demand increasingly powerful engines. When boiler pressure had exceeded 60 psi, compound engines achieved a thermo-dynamic advantage, but it was the mechanical advantages of the smoother stroke that was the deciding factor in the adoption of compounds. In 1859, there was 75,886&nbsp;ihp (indicated horsepower{{cref|ihp}}) of engines in mills in the Manchester area, of which 32,282 ihp was provided by compounds though only 41,189 ihp was generated from boilers operated at over 60psi.{{sfnp|Hills|1989|p=160}}

To generalise, between 1860 and 1926 all Lancashire mills were driven by compounds. The last compound built was by [[Buckley & Taylor|Buckley and Taylor]] for [[List of mills in Shaw and Crompton#V to Z|Wye No.2 mill, Shaw]]. This engine was a cross-compound design to 2,500 ihp, driving a 24&nbsp;ft, 90 ton flywheel, and operated until 1965.{{sfnp|Hills|1989|p=281}}