| 释义 |
prism|prɪz(ə)m|
Also 8 erron. prysm.
[ad. late L. prisma (Martianus Capella), a. Gr. πρίσµα a thing sawn, a prism (Euclid), f. πρίζειν to saw. So F. prisme (1680 in Hatz.-Darm.).]
1. Geom. A solid figure of which the two ends are similar, equal, and parallel rectilineal figures, and the sides parallelograms.
1570Billingsley Euclid xi. xl. 355 Euery parallelipipedon may be resolued into two like, and equal Prismes. 1706Phillips s.v., Triangular Prism, a kind of Prism whose two opposite Bases are Triangles alike, parallel and equal. 1806Hutton Course Math. I. 331 A Prism takes particular names according to the figure of its base or ends, whether triangular, square, rectangular, pentagonal, hexagonal, &c. A Right or Upright Prism..has the planes of the sides perpendicular to the planes of the ends or base. 1847Smeaton Builder's Man. 177 To find the Solidity of a Prism.
2. Any body or object of this form.
1661J. Childrey Brit. Baconica 81 In little Columnes, or Prismes an inch long or more. 1758Reid tr. Macquer's Chem. I. 191 An iron grate, the bars of which are quadrangular prysms of half an inch square. 1800tr. Lagrange's Chem. II. 105 The salt deposits itself in compressed prisms of great length. 1836Macgillivray tr. Humboldt's Trav. xvii. 232 A granitic prism, terminated by a flat surface covered with a tuft of trees, rises to the height of 213 feet. 1862Rawlinson Anc. Mon. I. v. 329 Hexagonal or octagonal prisms made in extremely fine and thin Terra Cotta.
3. Optics. A transparent body of this form, usually a triangular geometrical prism, of which the refracting surfaces are at an acute angle with each other. Nicol('s) prism = Nicol2.
1612Peacham Gentl. Exerc. iii. 150 A most pleasant and delightfull experiment..in a three square cristal prisme, wherin you shal perceiue the blew to be outmost next to that the red. 1656W. D. tr. Comenius' Gate Lat. Unl. §480. 139 Prismes (called fools paradises) which transform the colours of things into a thousand shapes. 1728–46Thomson Spring 208 Here, awful Newton, the dissolving clouds Form, fronting on the sun, thy showery prism. a1743Ld. Hervey Monimia to Philocles Poet. Wks. (1808) 48 So in a prism to the deluded eye Each pictur'd trifle takes a rainbow dye. 1847De Morgan Formal Logic ii. 35 Wollaston and Fraunhofer have discovered black lines which always exist in the spectrum of solar colours given by a glass prism, in the same relative places. 1873J. P. Cooke New Chem. 57, I have a prism..made of Icelandspar, and called a Nicol prism.
b. fig.
1820W. Irving Sketch Bk. II. 207, I had surveyed the landscape through the prism of poetry, which tinged every object with the hues of the rainbow. 1847L. Hunt Men, Women, & B. I. viii. 140 A bit of health is a fine prism to see fancies by. 1874Sayce Compar. Philol. i. 35 Thought and its expression are but the two sides of the same prism.
c. Loosely used for a spectrum produced by refraction through a prism; pl. prismatic colours.
c1840Mrs. Opie in Miss Brightwell Mem. xxii. (1854) 334 Oh! the exquisite beauty of the prisms on my ceiling just now. 1842Tennyson Day-Dream, Sleeping Pal. v, The beams, that thro' the Oriel shine, Make prisms in every carven glass, And beaker brimm'd with noble wine. 1866Cornh. Mag. Sept. 358 A glass drop chandelier, quaint and old-fashioned, reflected it [the light] in bright prisms.
4. Cryst. A ‘form’ consisting of three or more planes parallel to the vertical axis of the crystal. (Cf. dome n. 5 b.)
1878Gurney Crystallogr. 51 A group of tautozonal faces is in some cases called a prism. 1895Story-Maskelyne Crystallogr. v. §108 The prismatic forms..are constituted each of four planes, the first form being technically termed a prism.
5. Engineering. A length of cutting or embankment, treated roughly as a prismoid or a parallelepiped, of which the content is calculated by the prismoidal formula.
1906Rep. Board Consulting Engineers Panama Canal 25 Very accurate cross sections of the Canal Prism included between Obispo and Paraiso, seven miles and a half, were obtained. Ibid. 49 There is much rock to be removed from the Canal prism at Obispo.
†6. Sawdust. Obs. rare—0.
1656Blount Glossogr., Prism,..the powder or dust of those things that are cut with a Saw. a1700B. E. Dict. Cant. Crew, Prisme,..Saw-dust.
7. attrib. and Comb., as prism-form, prism-glass, prism-maker; prism-hued, prism-like, prism-shaped adjs.; prism-battery, an electric battery in which the materials forming the positive pole are compressed into a prism or block (Knight Dict. Mech. Suppl. 1884); prism-binocular(s), binoculars containing two pairs of triangular prisms, introduced so as to shorten the apparatus and improve the stereoscopic effect; prism-train, a combined series of prisms used with the spectroscope to give increased dispersion.
1666Boyle Orig. Formes & Qual. Wks. 1772 III. 56 These crystals..would shoot into prism-like figures, as roched petre. 1688R. Holme Armoury iii. 375/1 Prismes Glasses..represent things of diverse colours, as red, green, yellow, like a Rain-Bow. 1760J. Lee Introd. Bot. iii. xxii. (1765) 229 The Pericarpium is..prismatic, Prism-shaped. 1839Bailey Festus vi. (1852) 68 Joyous feelings, prism-hued. 1859R. F. Burton Centr. Afr. in Jrnl. Geog. Soc. XXIX. 134 The prism-shaped ceiling is composed of thin poles extending from the long walls to the centre. 1895Story-Maskelyne Crystallogr. vii. §328 One of these varieties [of prismatids] includes the vertical or ortho-prism..usually distinguished as the prism-form, the faces of which lie in the zone. 1901Brit. Optical Jrnl. Sept. p. iv (Advt.), Busch's Prism Binoculars... The lightest and most portable Prism Binocular on the market. 1919Jane's Fighting Ships 59 adv., Bausch & Lomb Optical Co... Field Glasses (Stereo Prism Binocular). 1957Encycl. Brit. III. 583/2 Ernst Abbe took the matter up de novo in 1893 when he designed prism binoculars and telescopes. His constructions were the forerunners of the modern prism binocular. |