Like many early mechanical devices, the first recorded wind-powered machines, seem to have been built as toys or concepts

for other seemingly more practical things or interesting oddities. Heron of Alexandria's

first century AD wind-driven organ, for instance, is said to have been devised as a whimsical

sort of plaything,

rather than as a method of harnessing the power of wind for large scale, arguably more

impressive feats. Other quite early uses of the wind as a power source include a variety

of what are often called prayer wheels in modern day Tibet and China. These prayer,

or moni wheels, are rotated horizontally by the wind and are meant to symbolically accumulate

good karma and eliminate bad karma for the bearer of the smaller portable versions and the

visitors to the larger versions of these devices.

The earliest economically productive windmills were also of the horizontal variety,

were sometimes called penemonee windmills, and typically had blades or sails arranged vertically around a central rod. Those blades or sails

catching the wind, rotating the rod in a vertical cylindrical motion. That rod would be attached to

an axle, which would be attached to a mechanism that would channel the captured wind power into

manual labor, often some kind of grain grinder, work that would otherwise be quite tedious and

physically intensive, but which could be done pretty much all day by the wind if the mill

was built correctly and kept in good repair.

These horizontal windmills, despite being the least efficient,

in terms of labor power output generated per unit of wind power available,

is one of the most geographically widespread and commonly reinvented across time and space.

Many cultures around the world came up with their own versions of it, at some point in their history,

and we have archaeological evidence of such windmills from as far back as the 7th century AD,

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