Discussion (Continued from Vol. VI., No. I.) MR. H. ADAMS stated that in Mr. Brinsden's paper the grading analysis was given but not the influence of the grinding or the grading, and he would like to know whether a better roast could be obtained by crushing through a 700 or 1200 mesh on the ball mills: He would expect to get a better roast with the finer mesh. It was said that if the ore were too fine the layer of ore in the furnace was not sufficiently porous to allow the air to get through it, and thereby caused an insufficient roast. On the Chaffers mill they desired to relieve the pans of work, and so _ they put 1200-mesh screens on the mill. He would like to know whether the finer material would affect the roast.