Variations in the water level of the river Bollin, which supplied the water wheels became problematical, as the need for power in the mill increased, so the Gregs diversified into steam power.

This working beam engine is very similar to the 20hp Boulton & Watt engine that was fitted here in 1834. Watt's use of a separate condenser made the engine more efficient than the Newcomen design which preceded it.

en.wikipedia.org/wiki/Boulton_and_Watt