A wheat lamp is a type of incandescent light designed for use in underground mining, named for inventor Grant Wheat and manufactured by Koehler Lighting Products in Wilkes-Barre, Pennsylvania

Wilkes-Barre, Pennsylvania

Wilkes-Barre is a city in the U.S. state of Pennsylvania, the county seat of Luzerne County. It is at the center of the Wyoming Valley area and is one of the principal cities in the Scranton/Wilkes-Barre metropolitan area, which had a population of 563,631 as of the 2010 Census...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, a region known for extensive mining activity.

A safety lamp

Safety lamp

A safety lamp is any of several types of lamp, which are designed to be safe to use in coal mines. These lamps are designed to operate in air that may contain coal dust, methane, or firedamp, all of which are potentially flammable or explosive...

 designed for use in potentially hazardous atmospheres such as firedamp

Firedamp

Firedamp is a flammable gas found in coal mines. It is the name given to a number of flammable gases, especially methane. It is particularly commonly found in areas where the coal is bituminous...

 and coal dust, the lamp is mounted on the front of the miner's helmet

Miner's helmet

A Mining helmet is a type of helmet worn for safety purposes by miners while in the process of underground mining, similar to a hard hat. They sometimes have an electric light affixed.-Examples:* Comfo-Cap, manufactured by Mine Safety Appliances...

 and powered by a wet cell battery worn on the miner's belt. The average wheat lamp uses a 3-5 watt

Watt

The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

 bulb which will typically operate for 5 to 16 hours depending on the amp-hour capacity of the battery and the current draw

Electric current

Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...

 of the bulb being used.

A grain of wheat lamp is an unrelated, very small incandescent lamp used in medical and optical instruments.