Bourn Windmill Bourn · Cambridgeshire · England

Bourn Windmill is an open-trestle post mill on Caxton Road, between Bourn and Caxton. Its body is carried on a central post supported by a trestle, and the whole mill is turned to face the wind. The form is an early and now rare type of English post mill, with only a small number of open-trestle examples surviving nationally.

The mill was standing by the seventeenth century. A deed records John Cook selling the mill in 1636 to Thomas Cook of Longstowe, and later documentation passed the mill from Thomas Cook to William Smythe, a blacksmith from Caxton. Recent dating of the main post has shown that the tree used for that major timber was felled in the first half of the sixteenth century, giving the mill exceptional significance among surviving windmills.

Ownership changed repeatedly during the working life of the mill. By 1701 it was owned by John Bishop, a baker, and it remained associated with the Bishop family until 1875. The mill served the local grain-growing landscape, first in the open-field setting around Bourn and later in the enclosed landscape created after 1806. Carved initials inside the mill preserve traces of the families connected with its working life. The machinery dates mainly from the nineteenth century, and the trestle was renewed in oak in 1874.

The mill continued to work by wind into the twentieth century. Auxiliary oil-engine power was introduced in the 1920s, and commercial milling ended in 1926 or 1927. Soon afterwards the mill was secured for preservation. Mansfield Forbes helped arrange its purchase, with support from The Pilgrim Trust, and it passed into the care of the Cambridgeshire Preservation Society, now Cambridge Past, Present & Future, in 1932.

Bourn Windmill is protected as a Grade I listed building and as a scheduled monument. Repairs were carried out in the 1960s, and a further restoration campaign took place between 2000 and 2004. In 2020 rot was found in the crosstrees and supporting timbers, creating a serious structural risk. The mill was added to the Heritage at Risk Register in 2021. A repair campaign supported by The National Lottery Heritage Fund, Historic England, SPAB Mills, and local donors funded work to the trestle and high-level fabric. After three years of closure for essential restoration, Bourn Windmill reopened in 2023. It remains a landmark of the west Cambridgeshire countryside and a rare survival of early English wind-powered corn milling.