Water wheel

Water wheel, wheel that is turned by flowing water, providing power to operate a device. The running water may come from rivers or waterfalls. Water wheels were used by ancient Romans to grind grain and in time were developed to run other devices, such as machinery. There are 2 basic types: vertical and horizontal. Vertical water wheels often have containers around the wheel. Water usually flows into a container at the top of the wheel, the weight of the water causes the container to fall, and the water flows into the next container, creating a constant motion. Horizontal water wheels have vertical blades. Water strikes the blade on one side of the wheel, causing the wheel to turn to the next blade, thus creating continual motion. Horizontal water wheels are capable of converting more water power into energy and have greater use in the modern world.

See also: Water power.