What is paddle wheels?

Paddle wheels are rotary devices that consist of a wheel with a series of paddle blades attached around its circumference. The wheel is usually powered by steam, hydraulic or manual mechanisms, and the paddles are designed to push water or air in a particular direction. Paddle wheels have been used in a variety of applications over the years, including for powering riverboats and steam locomotives. In modern times, paddle wheels are still used in some industrial applications, such as in water treatment or for cooling towers. They are also used as decorative elements on some riverboats and other historical or replica vessels.