History
In the 18th century there were already a large number of water and steam powered corn mills in Wandsworth, producing flour on an industrial scale. Many of these were owned by John Watney, whose house 'Rushmere' still stands on Southside, Wimbledon Common. While it seems strange that in 1799 he should apply to the Manor Court to enclose a piece of land on Wimbledon Common for the purpose of erecting a windmill, it appears that the residents of Wimbledon were not wholly satisfied with factory produced flour and wanted to have their own mill for local use.
​
John Watney died before he had put his plan into effect, and it was not until 1816 that a new application was made by a Roehampton carpenter, Charles March. The following year he was granted a 99-year lease on a small plot of land on Wimbledon Common, at an annual rent of two shillings, 'upon this special condition that he shall erect and keep up a public Corn Mill for the advantage and convenience of the neighbourhood'.
Construction
Charles March was a carpenter rather than a millwright, and this may account for the unusual construction of the mill. Originally the single-storey octagonal brick base together with a second storey constructed of wood housed all the working machinery. Above this was a conical tower which held the post supporting the cap on which the sails were mounted.
​
The post was hollow so that an iron shaft could be taken down inside it to turn the millstones on the floor below. It was therefore known as a hollow-post mill. While common in Holland, such mills are most unusual in this country but a mill of this type existed in Southwark, near the site of the old Globe theatre, so Charles March probably copied this design, being ignorant of more usual windmill practice.
​
The sails, which had a span of about 15m, were mounted on a cast iron shaft 2.4m in length which also carried a 1.8m diameter iron wheel with wooden cogs; this drove a smaller bevel gear known as a wallower, mounted on the top of the vertical shaft which ran down the inside of the hollow post. The larger wheel was known as a brakewheel as it could be clamped by a wooden collar when it was needed to stop the sails turning.
​
The main shaft drove the great spur wheel on the ground floor, from which two smaller gearwheels (known as spur nuts) took the drive back up to the first floor where there were two pairs of millstones 1.3m in diameter. In each pair the top stone turned while the bottom stone remained fixed, grinding the grain as it passed between them.
​
The whole cap carrying the sails rotated round the post so that the sails could be turned into the wind. This was done automatically by a series of gears driven by the fantail mounted on the back of the cap. The sails themselves were of the patent type with opening shutters controlled by striking gear operated by a chain hanging from a wheel below the fantail staging.
​
Download a diagram of the windmill as it was in its working days.
The day the windmill stopped
The mill stopped working in 1864 when the Lord of the Manor, the 5th Earl Spencer, announced his intention to enclose Wimbledon Common and build himself a new manor house on the site of the mill. Local opposition led to a legal battle lasting six years which was resolved by the Wimbledon and Putney Commons Act of 1871 which handed over the commons to the local community, together with the burden of maintenance and an annuity to be paid to the Spencer family.
​
The mill was operated at the time by the Marsh family, who also had mills in Kingston. They were persuaded to sell the Wimbledon mill, but insisted on removing the stones and most of the machinery so that the mill could not be run in competition with their other mills.
​
After it stopped working the mill was converted into living accommodation for six families. The original wooden upper storey was rebuilt using brick, and fireplaces and chimneys were added to give the building the appearance it has today. One room has been retained in the Museum to give an idea of the living conditions in 1870.
Restoration
In 1893 a major restoration took resulted in a number of changes to the building. The cap was reduced in height and the tower made taller, to retain the same overall height of the mill. The post supporting the cap was removed and an iron bearing was fitted to the top of the tower so that the cap could continue to turn with the wind.
​
The mill continued to be used as accommodation, latterly for the Commons Rangers, until 1975, when further repairs were carried out and the first floor was converted into a museum. A grant from the Heritage Lottery Fund in 1999 enabled the sails to be restored to working order and the museum to be extended to the ground floor.