crown glass

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.

Japanese Meaning

初期の窓用ガラス。ガラスを中空の球状に吹き出し、その後、定められた道具上で再加熱・遠心力により扁平な円板に成形されたガラス。

What is this buttons?

The old cottage's leaded windows still contained intact panes of crown glass, their subtle ripples catching the morning light.

Google Translation / DeepL Translation

その古いコテージの鉛入り窓には、吹きガラスで球体を作り、加熱して回転させて平らな円盤にした初期の窓ガラスの無傷の板が今もはめられており、微かな波打ちが朝の光を捉えていた。

Details

Sense（1）

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.

Sense（2）

(optics) 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.