Smoked glass is

glass Glass is an amorphous (non-crystalline solid, non-crystalline) solid. Because it is often transparency and translucency, transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window pane ...

held in the

smoke Smoke is an aerosol (a suspension of airborne particulates and gases) emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwante ...

of a

candle A candle is an ignitable candle wick, wick embedded in wax, or another flammable solid substance such as tallow, that provides light, and in some cases, a Aroma compound, fragrance. A candle can also provide heat or a method of keeping time. ...

flame (or other inefficiently burning

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...

) such that one surface of the sheet of glass is covered in a layer of smoke residue. The glass is used as a medium for recording pen traces in

scientific instrument A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research. History Historically, the definition of a scientific instrument has varied, based on usage, laws, an ...

s, and is also used to track pheromone deposition in ants The advantages of using the glass are that the recording medium is easily renewable (just re-smoke the glass), and that the trace obtained can easily be magnified by

projection Projection or projections may refer to: Physics * Projection (physics), the action/process of light, heat, or sound reflecting from a surface to another in a different direction * The display of images by a projector Optics, graphics, and carto ...

onto a suitable surface. A variation on this scheme is the use of smoked paper in early

seismograph A seismometer is an instrument that responds to ground displacement and shaking such as caused by quakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The out ...

s. The effect of smoked glass can be incorporated into glass manufacture by adding darkening materials, such that light passing through the glass is decreased in

brightness Brightness is an attribute of visual perception in which a source appears to be radiating/reflecting light. In other words, brightness is the perception dictated by the luminance of a visual target. The perception is not linear to luminance, and ...

. It can be used aesthetically, for example, in the manufacture of

coffee table A coffee table is a low table designed to be placed in a sitting area for convenient support of beverages, remote controls, magazines, books (especially large, illustrated coffee table books), decorative objects, and other small items. Most cof ...

s with smoked glass tops. It can also be used in scientific instruments as a

filter Filtration is a physical process that separates solid matter and fluid from a mixture. Filter, filtering, filters or filtration may also refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Fil ...

, as in the use of smoked glass in cross-staves and

sextant A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of cel ...

s, allowing operators to make

sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

sightings without damaging their

eyesight Visual perception is the ability to detect light and use it to form an image of the surrounding environment. Photodetection without image formation is classified as ''light sensing''. In most vertebrates, visual perception can be enabled by ph ...

References

{{glass-stub Glass coating and surface modification Smoke

See also

References