A flame spreader is a small metal component in an oil or paraffin lamp burner that shapes and widens the flame so that it burns brightly and evenly. It commonly takes the form of a disc or button fixed at the top of the central air tube in a round-wick burner, deflecting the rising air outwards so that the flame opens into a broad, tulip-like crown. In flat-wick burners a slotted dome or gallery performs a similar role.
The principle developed from the work of Aimé Argand, whose late eighteenth-century burner introduced a hollow circular wick fed with air from the centre and outside. During the second half of the nineteenth century, central-draught burners for paraffin lamps were made by many firms, each relying on a correctly fitted spreader to give a clean light without smoking. Sitting in the hottest part of the lamp, spreaders often burn out, distort or go missing, and lamps found today are frequently without them. When restoring an antique oil lamp for use, it is important to obtain a spreader of the right size and type for the burner, as an ill-fitting one will produce a poor, smoky flame and may damage the glass chimney.
