| 释义 |
hydrostatic, a.|haɪdrəʊˈstætɪk|
[Ultimately f. Gr. ὑδρο- water + στατικ-ός making to stand, balancing, weighing (see static); but prob. proximately f. Gr. ὑδροστάτης a hydrostatic balance, in med.Gr. a fire-engine, which prob. originated mod.L. hydrostaticus, F. hydrostatique.]
1. Relating to the equilibrium of liquids, and the pressure exerted by liquids at rest; belonging to hydrostatics.
hydrostatic paradox: the principle (depending on the law of uniform pressure of liquids) that any quantity of a perfect liquid, however small, may be made to balance any quantity (or any weight), however great. (Cf. hydrostatic bellows in 2.) hydrostatic arch: see quot. 1858.
1671R. Bohun Wind 258 Illustrated from Hydrostatique experiments. 1729Switzer Hydrost. & Hydraul. 207 Hydrostatick Instruments. 1797Hydrostatic paradox [see 2]. 1858Rankine Applied Mechanics §183 The Hydrostatic Arch is a linear arch suited for sustaining normal pressure at each point proportional, like that of a liquid in repose, to the depth below a given horizontal plane. 1860Hartwig Sea & Wond. i. 16 The mixture of the water of rivers with that of the sea presents some hydrostatic phenomena which it is curious enough to observe. 1871B. Stewart Heat §23 The hydrostatic pressure of the column of mercury.
2. Used to denominate various instruments and appliances involving the pressure of water or other liquid as a source of power or otherwise.
hydrostatic balance: a balance for ascertaining the specific gravity of substances by weighing them in water. hydrostatic bed: a bed consisting of an india-rubber bag filled with water; a water-bed. hydrostatic bellows: a contrivance for illustrating the law of uniform distribution of pressure in liquids; it consists of a bellows-like chamber, into which water, being introduced by a narrow vertical tube, supports a weight placed on the upper board of the bellows, the upward pressure on this being that of the column of water in the tube multiplied in proportion to the area of the bellows. hydrostatic joint: a joint used in large water-mains, in which a ring of sheet-lead is made fast by the pressure of a liquid (usually tar) in an annular space within the bell of the pipe. hydrostatic press: a machine (having various practical applications) in which the pressure of a body of water (produced either by the weight of the water itself, or by a piston or other mechanical means) is transmitted from a cylinder of small sectional area to one of greater, and thus multiplied in accordance with the law of hydrostatic pressure. Also called hydraulic press or Bramah's press. hydrostatic weighing-machine: a machine of similar construction to the hydrostatic bellows, in which the weight of a body is indicated by the height of the column of water which supports it.
1755J. Shebbeare Lydia (1769) II. 87 It was impossible by the nicest hydrostatic-balance to decide which had the preference in her mind. [1797Nicholson's Jrnl. 29 Apr. (Heading), A New Press operating by the Action of Water, on the Principle of the Hydrostatic Paradox. Invented by Joseph Bramah, Engineer. ] Ibid. (Page heading), Description of a New Hydrostatic Press [Bramah's].1799G. Smith Laboratory I. 77 It [silver] loses in the hydrostatic balance about an eleventh part of its weight. 1822J. Imison Sc. & Art I. 111 The hydrostatic bellows is perhaps the best machine for demonstrating the upward pressure of fluids. 1833N. Arnott Physics (ed. 5) I. 589 In the hydrostatic bed, there is no tense surface or web at all: the patient is floating upon the water. 1898Daily News 5 Sept. 2/2 The use of ‘hydrostatic vans’ is now a luxury unknown in this arid portion of the town [i.e. East end of London during the ‘Water-famine’].
3. Used of or in reference to certain aquatic animals having air-bladders which enable them to float on the surface of the water.
1840F. D. Bennett Whaling Voy. II. 295 One of the many hydrostatic univalve shells which float upon the surface of the ocean. Ibid. 317 Air, in the form of small bubbles..fully accounts for the hydrostatic power the animal possesses. 1870Rolleston Anim. Life Introd. 75 The air-bladder of an ordinary Teleostean Fish..is..all but exclusively hydrostatic. |