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prismatic, a.|prɪzˈmætɪk|
[f. Gr. πρισµατ-, stem of πρίσµα prism + -ic. So F. prismatique (1690 in Hatz.-Darm.).]
1. Of or pertaining to a prism; having the form of a prism or prisms; prism-like.
prismatic powder: a gunpowder the grains of which are hexagonal prisms.
1709Pope Ess. Crit. 311 False Eloquence, like the prismatic glass, Its gaudy colours spreads on ev'ry place. 1812Sir H. Davy Chem. Philos. 73 Certain saline solutions likewise that shoot into prismatic crystals. 1843Portlock Geol. 146 The truly prismatic basalt is confined to narrow limits. 1880Times 27 Dec. 9/2 Prismatic powder was exclusively used during the gunnery trials on board.
b. absol. Short for prismatic powder.
1894Sir A. Noble in Nature 26 July 310/2 The erosive effect of cordite..is very slightly greater than that of brown prismatic, but very much higher effects can, if it be so desired, be obtained with cordite.
2. Of or pertaining to the optical prism; formed, effected, separated, or distributed by or as by a transparent prism; hence, of varied colours, bright-coloured, brilliant. Also fig.
prismatic colours, the seven colours into which a ray of white light is separated by a prism. prismatic compass, a surveying compass so arranged that by means of a prism the angle of position of the object sighted can be read at the same time as the object itself is seen.
1728Pemberton Newton's Philos. 332 The result..of mixing together all the prismatic colours. 1788V. Knox Winter Even. I. iii. 27 All the hues of the prismatic spectrum. 1820Hazlitt Lect. Dram. Lit. 308 [Jeremy Taylor's] style is prismatic. It unfolds the colours of the rainbow. 1859F. A. Griffiths Artil. Man. (1862) 371 The traversing may be performed..with the Prismatic compass. 1868Lockyer Guillemin's Heavens (ed. 3) 429 The light of this Nebula, unlike any other ex-terrestrial light which had yet been subjected to prismatic analysis, was not composed of light of different refrangibilities.
3. Cryst. = orthorhombic a.
1858Mayne Expos. Lex., Prismatic System{ddd}that derived from the great number and variety of the prisms it contains. 1868Dana Min. Introd. (ed. 5) 25 Orthorhombic system. (Also called Rectangular, Prismatic, Trimetric.) 1878Gurney Crystallogr. 37 There may be three planes of symmetry at right angles. Such crystals..belong to the Prismatic..System.
4. Comb. prismatic-cellular, of prismatic cells.
1854Woodward Mollusca ii. 292 The shell structure is prismatic-cellular, as first pointed out by Sowerby... In Cardium the outer layer is only corrugated or obscurely prismatic-cellular.
Add:[2.] b. Of a measuring instrument: incorporating or making use of a prism or prisms. prismatic binocular(s) = prism-binocular(s) s.v. prism n. 7; prismatic compass, a surveying compass so arranged that by means of a prism the bearing of the object sighted can be read at the same time as the object itself is seen.
1859F. A. Griffiths Artil. Man. (1862) 371 The traversing may be performed..with the Prismatic compass. 1865Reader 7 Oct. 409/2 A useful little instrument, called by the inventor a ‘Topograph’..combines a plane table, prismatic compass, level, and cinometer. 1960J. Glendinning Princ. & Use Surveying Instruments (ed. 2) ii. xiii. 278 The prismatic astrolabe is designed specially for the determination of latitude and longitude. 1974R. Pearsall Collecting & Restoring Sci. Instruments iv. 99 True field glasses had to await 1859 for the Frenchman A. A. Boulanger to introduce prismatic binoculars. |
