Glass made without lead or iron, originally in a circular sheet. Formerly used in windows, it is now used as optical glass of low refractive index.
冕（牌）玻璃
Example sentencesExamples
The two most common kinds of glass used for making achromats are crown glass and flint glass.
The other kind - called crown glass - was made by pouring molten glass out on a turntable and letting centrifigal forces spread it out from a central point.
The discovery of achromatic lenses made of flint and crown glass heralded a new era for telescope makers, but the same did not apply to the microscope.
Several panes of crown glass may be cut out of each disc.
Based of the research, crown glass has a refractive index in the range of 1.5 to 1.6.
The material's color approaches the water-white clarity of crown glass.
Note that the magnifying power of the crown glass is twice that of the flint in this combination, yielding a net power about half that of the crown element alone.
Progress in the production of window glass from the hand craft of blowing crown glass to large sheets of drawn glass in 1915 had a very noticeable effect on the appearance of buildings.
It retains many of its original Georgian features including sash windows, crown glass, ornate ceiling cornicing, dado rails and picture rails.
The ‘Barlow lens ‘, a modification of this telescope lens, is a negative achromatic combination of flint glass and crown glass.’
Definition of crown glass in US English:
crown glass
noun
Glass made without lead or iron, originally in a circular sheet. Formerly used in windows, it is now used as optical glass of low refractive index.
冕（牌）玻璃
Example sentencesExamples
It retains many of its original Georgian features including sash windows, crown glass, ornate ceiling cornicing, dado rails and picture rails.
Several panes of crown glass may be cut out of each disc.
The other kind - called crown glass - was made by pouring molten glass out on a turntable and letting centrifigal forces spread it out from a central point.
The discovery of achromatic lenses made of flint and crown glass heralded a new era for telescope makers, but the same did not apply to the microscope.
Progress in the production of window glass from the hand craft of blowing crown glass to large sheets of drawn glass in 1915 had a very noticeable effect on the appearance of buildings.
Based of the research, crown glass has a refractive index in the range of 1.5 to 1.6.
Note that the magnifying power of the crown glass is twice that of the flint in this combination, yielding a net power about half that of the crown element alone.
The ‘Barlow lens ‘, a modification of this telescope lens, is a negative achromatic combination of flint glass and crown glass.’
The material's color approaches the water-white clarity of crown glass.
The two most common kinds of glass used for making achromats are crown glass and flint glass.