Turning to a smaller matter, the hand-barrow coming from the drying stacks to the kiln is unprotected, which often means that a good brick is spoilt. Of course, we are not alluding, in this connexion, to what takes place during clamp stacking; the brick produced by such a process must take its chance. The method of stacking in the kiln or clamp is very often responsible for damage to the bricks. A common method is to build them sloping outwards, and all sorts of strains and stresses are thus set up, which have their effect in producing lines of weakness, if not of actual visible cracks. The “London stock,” if not a thing of beauty, is usually strong, and that in spite of the “breeze” which forms so many points from whence cracks radiate. We must not forget, however, that a really good London stock is, above all things, thoroughly burnt, and that is a set-off against the numerous and often wide cracks. We will assume that the brick has been either naturally or artificially dried, that no cracks have made their appearance, and that it is properly stacked in the kiln ready for burning. Now comes a most important part of the process. It is possible that any microscopic cracks will be closed by fusion or agglutination; but it more frequently happens that in unskilled hands the kiln is responsible for many cracked and “starred” bricks. To know exactly how to introduce the heat so gradually that the bricks shall not be impaired, is an art begotten only of considerable experience. Even when dealing with one particular kind of brick-earth, the maker must be careful to notice the relative moistness of his charge, and vary the mode of procedure accordingly. Suppose the brick to be as “dry as a bone” before being put in the kiln, we shall notice a considerable amount of moisture coming out of it as soon as the fires are alight; and if the heat is applied too suddenly, the bricks are not improved--they contract unevenly and too quickly, and warp. When well alight, care should be taken to keep the temperature as uniform as possible, and when sufficiently burnt it must be lowered by almost imperceptible degrees. Above all things, there should not be too great a disparity between the temperature in the kiln and the outside air when unloading. Except to those who had minutely studied this matter, such a precaution might seem superfluous; it may be that no damage caused will be visible to the naked eye, but the microscope frequently shows flaws due apparently to this cause. The manufacturer may test this for himself by heating a good, sound medium burnt brick to the temperature usually found in his kiln when unloading, and suddenly plunging it in snow. It is not, perhaps, that any one of these things is especially dangerous to the brick, but it is the combined effect of all of them trending in the same direction. We desire to be clearly understood on this point. The cracks produced may not seriously impair the strength of the