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expansion|ɛkˈspænʃən|
[ad. late L. expansiōn-em, n. of action f. expandĕre to expand.]
The action of expanding, the fact or state of being expanded.
I. Spreading out, unfolding, opening out.
1. a. The action or process of spreading out or unfolding; the state of being spread out or unfolded; the opening of a bud, flower, etc. Also, † a spreading out to view, a display.
1646Sir T. Browne Pseud. Ep. iv. v. 191 The..distance betwixt the extremity of the fingers of either hand upon expansion. 1656tr. Hobbes' Elem. Philos. (1839) 458 Whereupon there will follow a great expansion of light, with vehement flame. 1664Power Exp. Philos. ii. 101 The Spring of a Watch..if the String be broke..flyes out into its fullest expansion. 1701Grew Cosm. Sacra i. v. 28 The easie expansion of the wing of a bird. 1731Pope Ep. Burlington 145 The gilded clouds in fair expansion lie. 1847De Quincey Sp. Mil. Nun §8 (1853) 18 A mob orator, whose brawling mouth open to its widest expansion, [etc.]. 1867J. Ingelow Laurance, She..knew.. The pleasure of the leaf in exquisite Expansion.
b. The detailed expression of what is implicitly contained in a statement; the writing out in full the meaning of graphical contractions. Also in Alg. the process of working out a contracted expression (cf. expand 1 b.) and stating the result in full; the result or statement thus obtained.
1858Todhunter Algebra xxxvi. §519 The subject of the expansion of expressions is..properly a portion of the Differential Calculus. Ibid. xxxvi. §524 To find the number of terms in the expansion of any multinomial. 1886J. Edwards Diff. Calc. 96 Now assuming the possiblility of such an expansion, let, etc.
c. Naval Arch. The mathematical enlargement of a ship's lines from a drawing or model to the full size of building. Also attrib.
1869E. J. Reed Shipbuilding 186 Either a model of one side of the ship or an expansion drawing is prepared, on which to set off the edges and butts of the plates. Ibid. 439 An expansion batten is applied to the line on the floor representing the moulding edge of the frame. 1877Thearle Theor. Naval Archit. I. 163 When an expansion drawing is made, the several strakes of plating can be shown upon it, also their thicknesses... It is obviously impossible to calculate the position of the centre of gravity from an expansion.
2. concr. Anything that is spread out; an expanse; esp. the expanse of heaven, the firmament.
1611Bible Gen. i. 6 Let there be a firmament [marg. expansion] in the midst of the waters. 1659Pearson Creed (1839) 70 This house of God..is not all of the same materials..there is a vast difference between the heavenly expansions. 1760Beattie Lucretius i. 6 All that lies Beneath the starr'd expansion of the skies. 1823Lamb Elia Ser. i. xxvi. (1865) 211 Less time..than it took to cover the expansion of his broad moony face..with expression. a1845Hood Kilmansegg cxl, Venus and Mars Are rolling along in their golden cars Through the sky's serene expansion. 1862Ansted Channel Isl. i. iv. (ed. 2) 64 Some..flat expansions of hard..rock, afford a kind of irregular pavement.
fig.1662R. Mathew Unl. Alch. §57. 61 That ocean or expansion of wrath.
†3.
a. Extent; space to which anything is extended.
b. Pure space (see quot. from Locke).
1690Locke Hum. Und. ii. vii. §10 The capacious Mind of Man..extends its thoughts often, even beyond the utmost expansion of Matter. Ibid. ii. xv. §1 Distance or Space, in its simple abstract conception..I call Expansion to distinguish it from Extension, which by some is used to express this distance only as it is in the solid parts of Matter. 1712Blackmore Creation iv. (1718) 121 Lost in expansion, void and infinite. 1755in Johnson.
4. a. The action or process of causing something to occupy or contain a larger space, or of acquiring greater volume or capacity; dilatation; an instance of this.
1664Phil. Trans. I. 29 To prove the expansion of glass by heat. 1665Ibid. I. 49 What Bodies are expanded by being frozen, and how that expansion is evinced. 1692Bentley Boyle Lect. viii. (1693) 27 The condensation and expansion of any portion of the Air is always proportional to the weight and pressure incumbent upon it. 1782Specif. Watt's Patent No. 1321. 5 The piston continues to descend by virtue of the expansion of the steam. 1830R. Knox Béclard's Anat. 235 They are furnished with tensor muscles, whether proper, or simply by expansion of their tendons. 1875Ure Dict. Arts II. 319 s.v., Some remarkable examples of expansion are furnished by the influence of sunshine on the Britannia Tubular Bridge. 1882Vines Sachs' Bot. 874 These movements depend not upon alternate expansion and contraction of the tissue..but, etc.
fig.1634Habington Castara (Arb.) 103 My heart Expanssion wants, to thinke what now thou art.
b. of immaterial things.
1682Sir T. Browne Chr. Mor. 19 Spread not into boundless expansions either of designs or desires. 1856Sir B. Brodie Psychol. Inq. I. i. 31 A high education..may..have the effect of preventing the full expansion of genius. 1864D. G. Mitchell Sev. Stor. 69, I felt..an unusual expansion. 1879M. Arnold Mixed Ess. Pref. 7 The love of liberty is simply the instinct in man for expansion.
c. Comm. and Finance. (a) An extension (of business transactions). (b) An increase in the amount of the circulating medium. More fully expansion of the currency.
1847Craig, Expansion, in commerce, an increase of issues of bank notes. 1864in Webster. 1891Pall Mall G. 10 Nov. 7/1 In some directions there has been expansion, so that the losses have been partially neutralized.
d. Extension of the territorial rule or sway of a country.
1882J. R. Seeley in Macm. Mag. XLVI. 456 (title) The Expansion of England in the Eighteenth Century. 1903Sun (N.Y.) 1 Dec. 2 When he indorsed the doctrine of expansion the cheers were pronounced.
5. The amount or degree of dilatation.
1790Blagden in Phil. Trans. LXXX. 322 The whole expansion of pure spirit from 30° to 100° of Fahrenheit's thermometer, is not less than 1/25th of its whole bulk at 30°. 1816J. Smith Panorama Sc. & Art II. 32 Taking a proportional part of the difference of the two expansions. 1875Ure Dict. Arts II. 391 s.v., The expansion of the solid corresponding to two degrees of the thermometer, is twice the expansion which corresponds to one degree.
6. concr.
a. An expanded or dilated portion.
b. A product of expansion; what (a thing) is expanded into.
1860Tyndall Glac. ii. vii. 261 This lake [Geneva] is simply an expansion of the river Rhone. 1865Ruskin Sesame 178 A man has a personal work..and a public work..which is the expansion of the other. 1866Huxley Phys. ix. (1869) 239 The structure..of the sensory expansion in which the optic nerve terminates. 1882Vines Sachs' Bot. 544 The membranous expansions or appendages.
7. Steam-engine. The increase in bulk of the steam which takes place in a partially filled cylinder after communication with the boiler is cut off.
The improvement introduced by Watt's patent of 1782 consisted in the economizing of steam by allowing the piston to be propelled, during the latter portion of its excursion, by the ‘expansion’ of the steam first introduced. An engine in which this is done is said to work ‘by expansion’. A double (or triple) expansion engine is one in which the steam passes from one cylinder into another, so that the expansive force is used twice (or thrice).
1782[see 4]. 1819Rees's Cyclop. XXXIV. sig. M. 2 b (art. Steam-Engine), Mr. Watt's principle of expansion. 1874Knight Dict. Mech. I. 817/1 An automatic expansion is one which is regulated by the governor, and varies with the amount of power required. 1875R. F. Martin tr. Havrez' Winding Mach. 80 The engineman must be able to work his engine with a variable expansion with as great ease as an ordinary high-pressure engine. Ibid., MM. Scohy and Crespin..took out a patent for applying a system of expansion to winding engines.
8. attrib. and Comb., as expansion theory; expansion apparatus, chamber = cloud chamber (see cloud n. 12); see also quot. 1968; expansion board Computing, a circuit board that may be connected to or inserted in a computer in order to provide extra facilities or memory; expansion box, a chamber fitted to a pipe to allow for the expansion of the liquid, gas, etc., which flows through the pipe; expansion card Computing = expansion board above; expansion-coupling, -curb, -drum (see quots.); expansion-engine (see 7); expansion-gear, an apparatus for cutting off steam from the cylinder at a given point of the stroke; expansion-joint (see quots.); expansion-slide, a slide belonging to the expansion-valve, a valve which shuts off the steam in its passage to the cylinder.
1897C. T. R. Wilson in Phil. Trans. R. Soc. CLXXXIX. A. 267 (heading) Conditions to be satisfied by the *expansion apparatus.
1978Pract. Computing July–Aug. 4 The chassis houses the computer, power supply, fans, and has three additional slots for *expansion boards. 1985Acorn User Feb. 11/4 Watford Electronics' 32k RAM expansion board gives your Beeb 27k of program space plus 20k for graphics.
1838Civil Eng. & Arch. Jrnl. I. 237/2 As the water warms, it rises through the pipe into the *expansion box... To guard against the danger of exceeding the proper degree of heat, the expansion box is furnished with a pipe. 1939Jrnl. R. Aeronaut. Soc. XLIII. 748 The exhaust gases from a group of cylinders are discharged through a number of expansion boxes, the expansion boxes being shaped as a flattened streamline member lying in the airstream.
1982Pract. Computing Nov. 66 Very reasonably priced for those who already have an Apple II and *expansion card. 1986Managem. Accounting Aug. 56 If all the sockets on the Mother Board are filled..you will have to install an ‘expansion card’ to increase its memory.
1933Discovery Apr. 107/2 This recoiling nucleus..is an efficient ionizer and so can be detected either by its electrical effect or its track can be photographed in an *expansion chamber. 1968Practical Motorist Nov. 333/1 Expansion tank (chamber), a small tank connected to the overflow of the radiator on some modern cars which collects water and steam forced through the overflow pipe. The water is drawn back into the main system when the engine cools.
1874Knight Dict. Mech. I. 816/2 *Expansion-coupling. The coupling represented consists of an expansion-drum of thin copper x between the extremities of two pipes a i, Fig. 1901, which, in elongating, press the sides of the drum in, and draw them out in cooling.
1847Craig, *Expansion curb, in Horology, a contrivance for counteracting expansion or contraction.
1874Knight Dict. Mech. I. 816/2 *Expansion-drum, an arrangement by which an occasional change of speed may be effected.
1847Craig, *Expansion engine. 1886Pall Mall G. 21 Sept. 13/2 These steamers..are provided with triple expansion engines.
1850Pract. Mech. Jrnl. III. 28 (heading) Whitelaw's steam-engine *expansion gear. 1875R. F. Martin tr. Havrez' Winding Mach. 80 MM. Scohy and Crespin add to the regular form of cylinder the expansion gear of M. Meyer.
1849–50Weale Dict. Terms, *Expansion-joint, a stuffing-box joint connecting the steam pipes, so as to allow one of them to slide within the enlarged end of the other when the length increases by expansion. 1864Webster, Expansion-joint, an attachment of the framing to the boiler, which allows the boiler to expand without bending the framing. 1882Worc. Exhib. Catal. iii. 5 Samples of improved expansion joints.
1848E. Alban Steam Engine 261 The *expansion slide is made to act through the motion of the principal slide below.
1886F. B. Jevons in Jrnl. Hellenic Studies VII. 292 Every form of the *expansion theory [i.e. the theory that the Iliad is an ‘expansion’ of a smaller poem].
1849Fairbairn in Mech. Mag. LI. 255 A new construction of *expansion valves for condensing steam engines.
Add:[8.] expansion slot Computing, a socket in a piece of computing equipment to which an expansion board may be connected.
1980Practical Computing Aug. 82 (caption) The basic Tuscan board featuring the Z-80 CPU, 8k RAM, 8k ROM, on-board video and 1/0 section with five spare S-100 *expansion slots. 1990Which? Nov. 651/1 Many have expansion slots so that you can add extra memory, for example, but these are specific to each manufacturer, and your choice is limited. |