Hydraulics has proven to be the most efficient and economical system adaptable to aviation. First used by the ancient Greeks as a means of elevating the stages of their amphitheaters, the principles of hydraulics were explained scientifically by the seventeenth century scholars Pascal and Boyle. The laws discovered by these two men regarding the effects of pressure and
temperature on fluids and gases in confined areas form the basis of the principle of mechanical advantage; in other words, the “why and how” of hydraulics.