In 1885 a German scientist Robert Bunsen invented a device to mix air with natural gas in the correct proportions. The Bunsen Burner machine opened up many new opportunities for the use of natural gas in everyday use. Adding thermostatic devices to regulate the flame and so control temperature made it popular for heating and cooking. This invention helped change the use of natural gas from a wasted nuisance around oil and coal to a popular energy source.
Most heat sources of his time were smoky and inefficient. Bunsen found that by allowing the gas and air to mix prior to ignition, the resulting blue flame produced no smoke and very high temperatures. Air (about three volumes to every volume of gas) is drawn into the burner tube through which the gas issues by a fine jet at the bottom. The mixture burns with a non-luminous flame and the combustion is complete. The Bunsen flame has an 'oxidizing' zone, or outer envelope where oxygen is in excess, and a 'reducer' zone in the center where unburnt gases are to be found. A Bunsen Burner consists of a hollow metal barrel that has one or more openings at its base to allow the entry of air. Gas is piped in at the base, mixes with the air, and at the top of the barrel creates a flame of varying intensity. This depends
upon the ratio of air to gas.