Abstract: Apparatus for supplying fuel to the combustion chamber of a gas turbine engine is disclosed. Techniques for increasing combustion efficiency and for decreasing the percentage of noxious emissions in the effluent from the chamber are developed. Axially extending tubes are used extensively in the disclosed embodiments of the invention for premixing gaseous or vaporized fuel with air in the supply means upstream of the combustion chamber. In addition to operation on natural gas and vaporized liquid fuels, the embodiments shown are adaptable to efficiently burn gasified coal fuels having heating values as low as 80 BTU per standard cubic foot (BTU/scf).