[2] Union Mill was built in 1814 by Cranbrook millwright James Humphrey for Mary Dobell and was initially worked by her son Henry.

[4] In 1994 the fantail was blown off during a storm, damaging the sails as it fell and landing on a parked car.

[6] The mill is seven storeys tall, with a three-storey smock on a four-storey brick base, which consist of basement, ground, first and second floors.

[2] The mill was originally built with Common sails and a wooden windshaft, with a wide stage.

In 1840, Samuel Medhurst,[7] the Lewes millwright, fitted a cast-iron windshaft, and patent sails,[3] which span 68 feet (20.73 m).

[5] George Warren,[4] the Hawkhurst millwright fitted a fantail a few years later, giving the mill its current appearance.

At the bottom of the upright shaft is the great spur wheel, which drove three pairs of millstones, of which two remain.