Why Ancient Romans and 12th-century Scots can teach us about energy

Flour is once again being produced at Barry Mill in Angus, a process that dates back eight centuries at the site

Human beings have long harnessed the natural world’s power. The ancient Roman engineer Vitruvius famously described how a water mill worked.

“... at one end of the axle, a toothed drum is fixed. This is placed vertically on its edge and turns with the [water] wheel. Adjoining this larger wheel, there is a second toothed wheel placed horizontally by which it is gripped. Thus the teeth of the drum which is on the axle, by driving the teeth of the horizontal drum, cause the grindstones to revolve. In the machine, a hopper is suspended and supplies the grain, and, by the same revolution, the flour is produced,” he wrote.

Barry Mill in Angus, rebuilt in the 19th century, produced flour for nearly 800 years until it closed in 1982. It has now reopened thanks to a £2.4 million donation from a mystery benefactor | National Trust for Scotland

Whether or not people in 12th-century Angus knew of his design, they did build a water mill and production continued at the site for nearly 800 years until 1982. Now, following a £2.4 million donation from a mystery benefactor, Barry Mill, rebuilt after a fire in the 19th century, is producing flour once again.

As the modern world once again turns to the abundant power created by water, wind and sun, it’s very much a case of ‘back to the future’.