Dictionary

crown glass en · NOUN

Etymology

So called from a crown-like shape given to it in the process of blowing.

Meanings

1. (uncountable, usually) An early type of window glass made by blowing glass into a hollow globe (crown) and then flattening it on a punty, reheating and spinning out into a flat disk by centrifugal force.
2. (uncountable, usually) A variety of glass used in lenses and other optical components due to its low refractive index and dispersion. Originally crown glass was made from alkali-lime silicates with approximately 10% potassium oxide, but similar properties may be attained with other recipes.
   • The convex half of an achromatic lens is composed of crown glass.

Forms

Relateds

bullseye

Translations (3)

fi kruunulasi (type of window glass) · fi kruunulasi (variety of optical glass) · fi pullonpohjalasi (type of window glass)