SETTING THE BRICK.
" The setting or placing of the brick in the kiln is a part of the work that we must depend on to a great extent to have the pressed brick well burnt.
"The idea which has been gaining ground for some years that brick cannot be set in the kiln too high or the kiln too large, we think is a mistake. Of course we speak now of the old method of burning brick in regular old-fashioned kilns, or what are termed the Dutch kiln. There are, as you all well know, many other kinds of patent kilns that have been tried and are still in use in many parts of the country ; of these we cannot speak, as we have had no experience with them ; there fore, our ideas of them either ont way or the other would be of no particular value to any of you.
" But as to the setting of the brick in the open-top or Dutch kilns, we think that for burning of pressed brick a kiln should not be set over 36 to 38 courses high in all, that is from the bottom to the top of the kiln, including all the common brick in the kiln as well as the pressed brick. This, we think, is about as high as they should be set to burn economically and with safety to the pressed brick. Our reasons for this are that we think the quicker we can get the heat to the top of the kiln the better, as that is the part of course that is farthest from tht.. fire, and the hardest, as a rule, to reach. We think for the same reason that the brick should be set very open at the bottom and throughout the body of the kiln until they reach within four or five courses of the top, and then placed closer so as to hold the heat when it reaches that point.
" As to the time required to burn a kiln of pressed brick properly, it will of course depend somewhat on the kind of materials that are used in their manufacture, that is, as we have stated before, the materials used in making pressed brick differ very much, and some clays will take longer to burn into brick than others, but we do think that all brick are the better by being burnt just as quick as the nature of the clay will allow them to be fired "Some persons may think that this is a strange doctrine to advocate in brick burning, as we well know that almost all of the theories that have ever been advanced on this point have been to the effect that the more time you consume in burning brick the better the brick will be. My reasons for taking the
opposite view of this theory is that we think there is a certain amount of life (as we might term it for want of a better name) contained in the brick during the time it goes through the pro cess of heating, which we think should be taken advantage of and used as a part of the burning process. As an example, we will call your attention to the re-burning of brick. There are many of you no doubt that have had occasion to re-burn brick the second time, for the reason of their having been burnt too soft at the first firing. We know that this has been done very often, not only by setting parts of a kiln with them, but we have seen whole kilns of salmon brick re-fired the second time ; and you will find that when brick are brought in contact with intense heat the second time that the fire does not act as readily upon them as it did the first time, and while they may be burnt hard enough at the second firing, they certainly are not as good as the brick that are burnt to the right degree of hardness from a green state and at one burning.
" Hence, we claim that when we consume more time than is actually necessary to burn a kiln of brick, that the kiln becomes, to a great extent, somewhat in the nature of a brick that has come in contact with the fire a second time, or, in other words, you simmer away and destroy all the life which a brick has for fire before you commence to burn it, which not only adds to the expense of burning, but makes the brick of less market value.
" As to our own experience in the matter of burning brick, we will say that the brick-makers of Trenton have made that part of the business a study, and with some success, as some of you that are among us here to-day can testify, as we have had the pleasure of a personal visit from some few of you now present, and we shall be pleased at any time in the future to show more of you how pressed brick are burnt in Trenton, N. J.