crown glass (English, noun)
expansion: crown glass (usually uncountable, plural crown glasses)
Senses:
glosses: 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.
tags: uncountable
usually
topics: engineering
natural-sciences
optics
physical-sciences
physics
glosses: 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.
tags: uncountable
usually
Forms:
form: crown glasses
tags: plural