plural of fire-grate

(physics) a surface having many closely spaced lines or slits; used to produce optical spectra by mutual interference

A grate with a shutter behind it.

(physics) A form of diffraction grating optimized for high orders of diffraction

plural of echelle grating

Alternative form of fire grate

A grate used to hold the fuel in domestic fireplaces and in many forms of heaters and furnaces.

A form of grate for holding fuel, in which the bars rise above one another in the manner of steps.

A form of firebars, where sections of the grate may be rocked or tipped to break up clinker within the fire, or to drop the fire after a day's work.

plural of diffraction grating