The proper management of open-top kilns, especially in burning drain-tile, is discussed in a practical manner in the January (1889) number of the Drainage Journal as follows : " While it is true that open-top kilns are not generally in good favor among our leading tile manufacturers, it is also true that there are quite a number of them in use. They are not the best kilns, but they serve a good purpose oftentimes, where the burner knows how to burn in them. Indeed, we know some who burn excellent tile in open-top kilns. The suggestions that we make have a practical side in our judgment that will apply to other kilns in some respects. They are briefly as follows : Set the tile a little open in the corners and at points where the difficulty of getting a draft of heat is experienced. Make the openings over the heat flues larger at such points so as to allow the heat a freer passage, and closer at the points where it has been inclined to draw heretofore. In bringing the kiln to a red heat after the water-smoke is off, keep the spots that have been inclined not to burn well in advance of other portions of the kiln. It is pretty well known to burners that the hot places tend to get hotter. It will be well to keep the side arches where the tile have not burned well heretofore, in advance in the heating to water-smoke. The general firing of the kiln after the red-heat point has been reached should look sharply to the points suggested. Where there is a tendency in one portion of the kiln to fall behind, the burner may increase the heat in the better fuel used, or by using a fuel that will send a flame up through the ware, and thus increase the draft of heat at the point desired. After a high heat has been reached
in the kiln, except at such points as are inclined to lag, it is the practice of some, in the use of open-top kilns, to open the platting in the centre of the cooler spots, and set three or four large tile on top of each other, setting them in the opening in the platting. The tile serves as a flue to increase the draft and draw the heat through the cold spots. Others cover the hot spots of the kiln tight, and in this way drive the heat where it is wanted, which may be done by covering with sheet-iron, and afterwards throwing three or four inches of dirt on the iron. By tight planting in the way suggested, the heat can be taken to the sides, or to the centre, or to the centre and sides, as may be desired.
" Again, we call attention to the heat-flues. They may not be large enough or open enough on top, or too open ; also the setting of the ware of any kind will have much to do with the result in burning. The burner should be a man of good prac tical common sense, quick to observe what is going on, and al ways ready to apply the necessary means to get there,' as the boys say. "Talent know why this and that should be done, but it is tact' that knows how, seizes the opportunity and does it. The tact' men are in demand for burners. They make all kinds of kilns go."