_The Colour of the Converter Flame during the Bessemerising of Copper Matte._ [Illustration: FIG. 1. Flame at commencement of blow.] [Illustration: FIG. 2. Flame during the first or “slagging” stage.] [Illustration: FIG. 3. “White Metal stage.” Slagging of Copper.] [Illustration: FIG. 4. Flame during second or “blowing to blister” stage.]