For the subjects of this general heading see the articles Mechanics; Dynamics, Analytical; Gyroscope; Harmonic Analysis; Wave; **HYDROMechanics**; Elasticity; Motion, Laws Of; Energy; Energetics; Astronomy (Celestial Mechanics); Tide.

**HYDROMECHANICS** (Gr.

U3po ajXavuta), the science of the mechanics of water and fluids in general, including hydrostatics or the mathematical theory of fluids in equilibrium, and **hydromechanics**, the theory of fluids in motion.

The practical application of **hydromechanics** forms the province of hydraulics.

Ii&.p, water, bin apus, strength), the branch of **hydromechanics** which discusses the motion of fluids (see **Hydromechanics**).

The study of the physical properties of fluids in general constitutes the science of **hydromechanics**, and their applications in the arts is termed hydraulics; the special science dealing with the physical properties of gases is named pneumatics.