Thorneburry. – Owing to the small amount of light given by safety-lamps, a lamp has been made called the "Thorneburry lamp" (see Fig. 367)¹, which burns paraffin. It has a flat. wick, giving a larger flame than the ordinary lamp. There is a double glass, and down the intermediate space the inlet air descends to a hollow ring, whence it passes through wire gauze on to the lamp-flame; ametal chimney secures a good draught, and there is a metal shield. The entering air has to pass through three gauzes, B, A, and the horizontal gauze round the base of the chimney, and the escaping products of combustion through a long chimney and the gauze cover A.

¹ Instead of the burner shown in the figure, a vase shaped porcelain burner (Barton's patent) is now generally used with this lamp.