Abstract: A gas burner assembly for a baking furnace is described. It includes a burner tube having an open outer end and an open inner end, with the inner end being arranged to extend through an opening in a furnace wall. A connector is provided for connecting the burner tube to a fuel supply and an infra-red pyrometer is mounted at the outer end of the tube. The pyrometer is axially aligned with the burner tube such that in use the pyrometer is sighted axially through the burner tube and onto an internal furnace wall. This gas burner assembly is particularly useful for heating the flue of a ring furnace used in the production of carbon anodes in the aluminum industry.