Hydraulics is the practical application of fluid mechanics. It deals with engineering and scientific devices that control the flow, or movement, of liquids, such as valves, pipes, pneumatic controls, and nozzles; the manmade and natural environments that store, release, or channel liquids, such as dams, pumps, tanks, turbines, rivers, and canals; and the instruments that measure the flow of liquid through particular containers, channels, or systems, such as flow meters and pressure gauges. In large part, the theory of hydraulics is based on fluid mechanics, a dynamic field of science that has enjoyed explosive growth in the mid-1800s, and under certain conditions, hydraulics can also be applied to the flow of gases through a system. This application of concepts of hydraulics to gases generally occurs when the densities of the gases are kept within parameters at which the principles of fluid mechanics apply. Hydraulics encompasses the study...