crown glassn.

Brit.

/ˈkraʊn ɡlɑːs/,

/ˈkraʊn ɡlas/, U.S.

/ˈkraʊn ˌɡlæs/

Forms: see crown n. and glass n.¹

Origin: Formed within English, by compounding. Etymons: crown n., glass n.¹

Etymology: < crown n. + glass n.¹, so called with reference to the round shape the glass was initially blown into during manufacture and the resulting shape of the sheets.

A kind of glass of low refractive index and low dispersion made typically from silica, potash, and lime without any lead or iron, originally in circular sheets formed by blowing and spinning.Originally used for windows, crown glass is now mainly used for optical equipment. Combinations of crown glass with flint glass are used to make achromatic compound lenses.

ΘΚΠ

society > occupation and work > materials > derived or manufactured material > glass and glass-like materials > [noun] > glass > crown-glass

crown glass1694

table glass1728

crown1808

1694 Articles of Agreement in Mariner's Mirror (1940) 26 363 Sash windows..glazed with crown glass or the best Newcastle glass made like the crown glass.

1694 Building Accts. 1–31 Oct. in Wren Society (1937) XIV. 139 Ffor 22 cases of Crowne glass.

1719 Free-thinker No. 95. 1 A poor Barber..had above Fifty Shillings Worth of Crown-Glass demolished.

1759 J. Dollond in Philos. Trans. 1758 (Royal Soc.) 50 740 The crown glass seems to diverge the light rather the least of the two.

1829 Nat. Philos. (Libr. Useful Knowl.) I. Optics x. 27 The triple achromatic object-glass..consists of..a concave flint glass lens placed between two convex lenses of crown glass.

1889 Harper's Mag. July 254/1 Crown-glass is of far less importance now than its young rival, sheet-glass.

1922 T. M. Lowry Inorg. Chem. xxix. 498 If the glass contains barium instead of lime, it is described as a barium crown glass, or if zinc is present, as a zinc crown glass.

1979 J. Muirden Sidgwick's Amateur Astronomer's Handbk. (ed. 4) vi. 85 For optical cementing, Canada balsam is generally used, since..its refractive index is virtually identical with that of crown glass.

2010 Irish Times (Nexis) 7 Oct. 6 The readiness of the clients to undertake the enormously expensive job of restoring the windows, with their original crown glass.

This entry has been updated (OED Third Edition, June 2014; most recently modified version published online March 2022).

单词	crown glass
释义	crown glassn. Brit. /ˈkraʊn ɡlɑːs/, /ˈkraʊn ɡlas/, U.S. /ˈkraʊn ˌɡlæs/ Forms: see crown n. and glass n.¹ Origin: Formed within English, by compounding. Etymons: crown n., glass n.¹ Etymology: < crown n. + glass n.¹, so called with reference to the round shape the glass was initially blown into during manufacture and the resulting shape of the sheets. A kind of glass of low refractive index and low dispersion made typically from silica, potash, and lime without any lead or iron, originally in circular sheets formed by blowing and spinning.Originally used for windows, crown glass is now mainly used for optical equipment. Combinations of crown glass with flint glass are used to make achromatic compound lenses. ΘΚΠ society > occupation and work > materials > derived or manufactured material > glass and glass-like materials > [noun] > glass > crown-glass crown glass1694 table glass1728 crown1808 1694 Articles of Agreement in Mariner's Mirror (1940) 26 363 Sash windows..glazed with crown glass or the best Newcastle glass made like the crown glass. 1694 Building Accts. 1–31 Oct. in Wren Society (1937) XIV. 139 Ffor 22 cases of Crowne glass. 1719 Free-thinker No. 95. 1 A poor Barber..had above Fifty Shillings Worth of Crown-Glass demolished. 1759 J. Dollond in Philos. Trans. 1758 (Royal Soc.) 50 740 The crown glass seems to diverge the light rather the least of the two. 1829 Nat. Philos. (Libr. Useful Knowl.) I. Optics x. 27 The triple achromatic object-glass..consists of..a concave flint glass lens placed between two convex lenses of crown glass. 1889 Harper's Mag. July 254/1 Crown-glass is of far less importance now than its young rival, sheet-glass. 1922 T. M. Lowry Inorg. Chem. xxix. 498 If the glass contains barium instead of lime, it is described as a barium crown glass, or if zinc is present, as a zinc crown glass. 1979 J. Muirden Sidgwick's Amateur Astronomer's Handbk. (ed. 4) vi. 85 For optical cementing, Canada balsam is generally used, since..its refractive index is virtually identical with that of crown glass. 2010 Irish Times (Nexis) 7 Oct. 6 The readiness of the clients to undertake the enormously expensive job of restoring the windows, with their original crown glass. This entry has been updated (OED Third Edition, June 2014; most recently modified version published online March 2022). < n.1694
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