by Bert Meinders

Created on: October 05, 2008

In the beginning, grain was made into flour by being crushed between two stones rubbed together. This was hard, monotonous work, and people looked for easier ways to achieve the same result.

The first improvement was rotary grinding. The millstones were made round, and one, usually the upper stone, was made to revolve. Even when done by hand, this method was more productive than its predecessor. A fit man could grind up to four kilograms of grain in an hour. For small groups of people, this was adequate. Much of the grinding was done by slaves.

For larger communities, more flour was needed and larger stones were used, turned by animals or slaves. A fit horse could grind ten times as much grain as a fit man. No one knows for how long such methods were standard, but another change came in the second century BC (on the basis of present knowledge). In Greece, some time between 200BC and 100 BC, moving water was put to work. Until recently, archaeologists believed that small horizontal wheels came first, driving the upper stone directly by a shaft which also supported the stone, its height adjusted either by wedges or levers to set the clearance between the stones. Eventually, vertical (horizontzl axis) wheels were introduced, gears to turn their motion through a right angle to drive horizontal stones. It is now believed, in part because of a very precise recent translation of verses by Antipater of Sidon, that both types originated simultaneously, the horizontal wheels for small applications and the vertical wheels for larger ones.

Water mills spread to most parts of the world where cereals were ground into flour. They became part of the feudal system in many places; the Lord of the Manor had the exclusive right to operate a mill, and there were severe penalties for grinding one's own grain.

As this development was taking place, the millstones themselves were also developing. The small conical stones from handmills became large flat stones, with small pits chiselled into them to facilitate movement of the meal outwards from the centre of the stones. These pits evolved into radial grooves, then grooves, either straight or curved, tangential to the centre hole. Sometimes these grooves were branched. The grooves, besides facilitating movement of the meal, guided air into the meal to cool it during grinding.

But what of places without falling water?

In Afghanistan and Eastern Persia, horizontal windmills appeared from the eighth century AD. They were not particularly efficient,

• 1
• 2
• Next Page >>