Castleton Mill

Castleton Mill is a water pumping mill built in 1869 by John Lawson for the Sherborne Local Board of Health. It was extended and its wheel replaced in 1898, with some alterations made in the late 20th century. The mill is constructed from coursed rock-faced stone and has a roof made of Spanish slates, which replaced the original Welsh slates. It is a single-storey building with one front bay added in 1898, and a wheel-chamber at the rear fed by three leats at different levels.

The mill features a chamfered plinth and round-arched windows with chamfered sills and small-pane glazing. The gable front includes a segment-arched doorway on the left with diagonally-boarded double doors, and a window on the right. The raised verge has shaped kneelers and coping with a roll-moulded apex. On the right side, there is a projecting wheel and a stack with a gabled base. The rear of the mill has two boarded-up windows and an arched pipe below the right window for leading water to the wheel. The left side has a window to the right and a projecting attached stone wall at the center, which is not of special interest, along with an opening for the lower-most water-feed. Above this opening, an iron pentrough projects from the wall, which used to carry water to the wheel at the highest feed level.

Inside, the front bay has an encaustic tile floor and a pit for former pumps. The wheel chamber retains the 1893 39-inch pitch-back water-wheel made by Edward White of Redditch, which is 26 feet in diameter. It features a perimeter drive, though the gearing has been removed, and it originally drove three vertical drive pumps. The original water tank and launder, cast by Sothert and Pitt of Bath, are still present, along with the winding gear to control the water supply. The water wheel is unusually large and is a rare survival, while the complex planning of the feed system, which accommodates three different sources of water and the nearby railway, is of particular interest. The mill was intended to pump water to Sherborne but could not meet the demand, leading to the construction of a turbine-powered pump-house nearby in 1874 and its own extension in 1898.