Crown glass
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
crown glass
[′krau̇n ‚glas] (materials)
A soda-lime glass, typically having 72% SiO2, 13% CaO, and 15% Na2O, which is hard and will take a simple polish; highly transparent for visible light.
Crown glass
1. An early form of window glass, cut from blown disks.
2. The glass made by blowing a mass of molten material, which is then flattened into a disk and spun into a cular sheet.
See also: Glasscrown glass
A handmade glass of soda-lime composition, used for windows; manufactured in the early 19th century by a now-obsolete process in which a hollow sphere of glass was blown while still very soft, then spun to form a large, nearly flat circular disk. During the spinning process, ripple lines were formed in a pattern of concentric circles, with their center at the center of the spun disk; this central area was used in a bull’s eye window. Also see glass.