SETTING BRICK IN THE All brick-makers recognize the importance of properly burn ing their wares. This cannot be done, however skilful the burner may be or how good the kiln, unless the brick have been properly set in the kiln ; and much of the bad burning is due to ignorant or careless setting of the brick. A slight ob struction will change the course of heat, it being most sensitive. It is necessary that the spaces left for draft be, as nearly as practicable, uniform throughout the kiln. Where they are set three over three or eight over eight, the setter has a guide, and only by carelessness can he go wrong ; but in the setting of the benches and overhanging courses he has no such guide and must use his skill.
Most setters hack the brick in the benches, that is, break joints. This is, I think, a mistake, as it prevents the heat from moving upward from the benches to the body of the kiln, so that all the heat must pass through the overhanging courses to reach the body of the kiln.
The benches should be set so that the heat can get into them from the arch or fire-flue and be able to pass freely from the benches directly upward into the kiln. I will illustrate my idea by the following diagram : Fig. 51 represents ground plan of the bench between eyes or arches of kiln. This is a three-brick bench with a stretcher between, known as a three-and-a-third-brick bench. The brick are set in pairs as shown.
Fig. 52 is the elevation of end view of bench, showing stretchers in third, sixth and ninth courses in middle course up to overhangers ; then each alternate course in middle between overhangers in stretchers.
Fig. 53 is elevation of bench next to fire flue or arch show ing first and second and fourth and fifth courses set in pairs, one directly over the other.
This shows only six courses. I think it better to set nine straight courses as shown in Fig. 52, the third, sixth and ninth courses tight as in Fig. 53 ; the third, sixth and ninth courses in middle bench, which are on a level with tight courses in bench next to fire, are set stretchers as shown in Fig. 52. This
allows the heat to pass horizontally into middle bench, then vertically between the pairs and through stretcher courses into the kiln. When they are set in pairs they have one straight face. The stretcher between the courses from bottom to top prevents the fire from running from one arch to the other, as it will do when one arch is hotter than the other, but still allows sufficient circulation of heat through the bench. There is but one tight course above the bench, that is the binding course, which is immediately over the closing courses—one-half resting on each course. This is set tight only on the " quarters " of the kiln, and loose next to the wall and through centre of kiln. I think in setting above the arches they should be set with a little space for draft next to the wall and across each end. Set top course same as the balance, and use two courses flat, on top bottom course, crosswise of top edge course and one inch between brick, top course to be of good square-burned brick crosswise of bottom course and close together.
In the manufacture of pressed brick and of brick which are repressed after they come from the dry-clay or mud-brick machines, much depends upon the manner and care shown in setting the green brick in the kiln. The bottom must be level, and each brick exactly over the one it faces, and not project ing either sidewise or endwise, so as to have a perfect face. They must then be water-smoked and burned carefully, and the kiln settled level. They should be perfectly dry when set, and set on dry common brick to prevent whitening on the surface when burnt.
Some manufacturers do not use brick barrows or cars in moving the pressed or re-pressed brick from the dryers to the kiln, the brick when dry being placed on pallets, which are placed one on top of the other.
The wheelers take two pallets with twelve brick and carry them to the kiln on their shoulders ; the setters take them from the wheelers, thus avoiding any chipping of the brick in the handling.