Abstract: A heating element having at least one filament. The filament(s) are supported by an insulating trough which reflects heat and insulates a rear wall of a refractory tube within which said trough is mounted. The element may incorporate a metal rod located within, and substantially parallel to a longitudinal axis of the insulating trough. The metal rod enables an external electrical connection to be made with the filament(s) at one end only of the heating element such that all external connections to the outside power source may be made at the opposite end of the heating element.