Optics.
any of several types of high-quality, homogeneous, color-free glass, as flint or crown glass, having specified refractive properties, used in lenses and other components of optical systems.
[ 1740-50 ]
Optics.
any of several types of high-quality, homogeneous, color-free glass, as flint or crown glass, having specified refractive properties, used in lenses and other components of optical systems.
[ 1740-50 ]
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012