Clinker on Tube Plate.

Professor Goss tells us something about the cause of clinkering on the tube plate which no doubt has puzzled many firemen. It is due to a chemical action. Particles of coal which are fine enough to be caught up by the draught have (in the short distance they may travel), about the right conditions as to temperature, oxygen supply, and the time element, to bring them to this intermediate or easily fusible stage. They are thrown, therefore, against the tube plate in a semi-pasty condition. The outer surface glazes over, and no more oxygen reaches the interior. They are, however, subjected to the most extreme heat of the fire-box, sufficient to dissociate the remaining sulphur which, passing off as a gas, produces the spongy or honeycomb effect. The trouble is principally due to lack of air to effect proper combustion in the fire-box.