Hȳ'dro-stăt'ic or Hȳ'dro-stăt'ic-al, a.

a. [Fr. hydrostatique, from Gr. ὕδωρ, water, and στατικός, causing to stand, skilled in weighing, στατική, statics, from ἱστάναι, to stand.] Relating to hydrostatics; pertaining to, or in accordance with, the principles of the equilibrium of fluids.

Hydrostatic balance, a balance for weighing substances in water, for the purpose of ascertaining their specific gravities.—Hydrostatic bellows, an apparatus consisting of two disks connected by a band of leather, or other flexible material, around their edges, thus forming a water-tight case, with a long, upright tube inserted in the upper disk, into which water may be poured to illustrate the hydrostatic paradox.—Hydrostatic jack, or hydraulic jack, a portable hydrostatic press. [See Illust. of Jack and Hydrostatic Press.]—Hydrostatic paradox, the proposition in hydrostatics that any quantity of water, however small, may be made to counterbalance any weight, however great; or the law of the equality of pressure of fluids in all directions.—Hydrostatic press, an instrument or engine in which great force, with slow motion, is communicated to a piston by means of water forced into the large cylinder in which it moves, by a forcing-pump of small diameter, to which the power is applied, the principle involved being the same as in the hydrostatic bellows.

Fig. 1 is a section of what is known as the Bramah press. A is a pump with a safety-valve, E, to prevent over-pressure, and a plunger, B, which forces the water into the cylinder, C, when it lifts the piston, D, from which the power is derived. Fig. 2 represents the press as used in machine-shops for forcing wheels upon shafts, &c.