A wheat lamp is a type of

incandescent light An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxidat ...

designed for use in

underground mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...

, named for inventor

Grant Wheat Grant or Grants may refer to: Places *Grant County (disambiguation) Australia * Grant, Queensland, a locality in the Barcaldine Region, Queensland, Australia United Kingdom *Castle Grant United States * Grant, Alabama *Grant, Inyo County, C ...

and manufactured by Koehler Lighting Products in

Wilkes-Barre, Pennsylvania Wilkes-Barre ( or ) is a city in the U.S. state of Pennsylvania and the county seat of Luzerne County, Pennsylvania, Luzerne County. Located at the center of the Wyoming Valley in Northeastern Pennsylvania, it had a population of 44,328 in th ...

, United States, a region known for extensive mining activity. A

safety lamp A safety lamp is any of several types of lamp that provides illumination in coal mines and is designed to operate in air that may contain coal dust or gases, both of which are potentially flammable or explosive. Until the development of effectiv ...

designed for use in potentially hazardous atmospheres such as

firedamp Firedamp is any flammable gas found in coal mines, typically coalbed methane. It is particularly found in areas where the coal is bituminous. The gas accumulates in pockets in the coal and adjacent strata and when they are penetrated the releas ...

and

coal dust Coal dust is a fine powdered form of which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. It is a form o ...

, the lamp is mounted on the front of the

miner's helmet A hard hat is a type of helmet predominantly used in workplace environments such as industrial or construction sites to protect the head from injury due to falling objects, impact with other objects, debris, rain, and electric shock. Suspensi ...

and powered by a

wet cell battery An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negat ...

worn on the miner's belt. The average wheat lamp uses a three to five

watt The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Wa ...

bulb which will typically operate for five to 16 hours depending on the

amp-hour An ampere hour or amp hour (symbol: A⋅h or A h; often simplified as Ah) is a unit of electric charge, having dimensions of electric current multiplied by time, equal to the charge transferred by a steady current of one ampere flowing for on ...

capacity of the battery and the current draw of the bulb being used.L. C. Isley, A. B. Hooker, ''Permissible Electric Mine Lamps'', US Department of Commerce Bulletin No. 332, 1930, pp. 32-34 A grain-of-wheat lamp is an unrelated, very small

incandescent lamp An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxid ...

used in medical and optical instruments, as well as for illuminating

miniature railroad Railway modelling (UK, Australia, New Zealand, and Ireland) or model railroading (US and Canada) is a hobby in which rail transport systems are modelled at a reduced scale. The scale models include locomotives, rolling stock, streetcars, t ...

and similar models.

References

City of Marlborough
retrieved July 7, 2011. Mining equipment Types of lamp Safety equipment Mine safety Coal mining {{Mining-stub