The other essential natural gas invention was made in 1885, when Robert Bunseninvented the burner that is now named after him, the “Bunsen burner” (see Fig. 1.15), in which air and natural gas are mixed to produce a single open gas flame.The gas flame can be used for different applications, such as heating, sterilization, and combustion. A very common application of the Bunsen burner is to generate heat and be used as a heat source in laboratory experiments. An essential part of a Bunsen burner is the rubber tubing that is used to supply the gas, which is located at the bottom of the device. The flow of the gas can be adjusted with a gas valve located on the opposite side of the gas supply. Another important component of a Bunsen burner is the air hole. The air hole is also located at the bottom of the device, just above the gas inlet supply. The air hole allows for the mixing of the air and gas before combustion at the top of the device. Combustion of natural gas can produce 700–1600British thermal units (BTUs) of heat depending on the composition of the natural gas.