The burner proper is a cage or basket of specially prepared magnesia, which yields a warmer tone of light than any obtained hitherto, while not requiring so high a temperature before combustion. The cap, made of a fire-resisting substance, fits on to a tubular arrangement, R, fixed in the upper portion of the body of the burner. The latter is supplied by air entering at the cone, O, which terminates the inner chamber, K, of the heater, and also by that drawn in by the rising column of gas, passing before the orifices, D, which may be regulated at will. The small burner, I, which is kept constantly alight, heats the central compartment, K, the sides of which transmit heat to the gas circulating in the annular casing, L, of the compartment. The heated gas passes, by the passage, AA¹, into the space, C, where it becomes intimately mixed with the air entering at OP, and also with the outer air arriving by the lateral apertures, D. The _vis viva_ of the jet is diffused through this mixture, which thus becomes very intimate, when it penetrates into the tubular arrangement, R; combustion now taking place at the top, while the refractory cap emits a bright orange light of great steadiness. As it is not the flow of gas which determines the entrance of the outer air, the former may be used at any pressure--an advantageous arrangement in all respects. When the small burner, I, in the lower chamber is lighted, the products of combustion issue by the orifice, O, of the compartment, terminating in a needle like that of the steam injector; and the jet draws along the air entering the apertures, PP, above the cone. The gas from the pipe, arriving from the annular space, L, fills the two lateral pockets shown in dotted lines, and passes through the orifices, AA¹, which communicate with the upper chamber of the burner. The manner in which it is conveyed thence to the tubular arrangement has already been described. Fig. 2 shows a more simple method of carrying out the same principle, and of effecting a considerable saving in gas for a given intensity of light. In this form, a wick, T, impregnated with an alkaline earthy solution, a few seconds after lighting, affords a focus of white light remarkable for its steadiness and brilliancy. A draught of air is created by a jet of gas issuing from the hollow needle, B, and passing through the vessel, D, which is provided with orifices, O, for the entrance of air. The air and gas pass from D into C, whence (after their intimate mixture is effected) they pass into the tubular arrangement, F, at the top of which combustion takes place.