**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.

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.

The effects of friction and viscosity in diminishing the velocity of running water were noticed in the Principia of Sir Isaac Newton, who threw much light upon several branches of **hydromechanics**.