"Past the Pond Cottages (originally for lead smelting) and a footbridge is a picturesque pond, held by the Lower Dam, which was built in 1830 to harness the Brook. This stone-lined reservoir features a central drain plug. From high on its dam wall, a still-visible metal pipe conducted water to the wheel of the adjacent, second mill, dating from 1850, and still functioning as a sawmill at the turn of the 20th century." - https://en.wikipedia.org/wiki/Bentley_Brook