"From this it seems that there is very little difference be tween the cost of coal or oil unless some other consideration intervenes. But there is a consideration of the lesser expense of fitting up for oil, the saving of time in burning, the fewer hands required, and the ease with which the heat can be in creased. You may keep your brick at a dull-red degree of heat for any length of time and fail to burn them hard ; but if you can, in a shorter time, with oil, get the requisite temperature, then you do the work in less time and at a saving of fuel, for the radiation of the heat of a kiln in six or seven days is no small item. It seems to me that in this shortening of time and saving thereby is the principal argument in favor of oil over coal ; but it becomes us to consider whether the difference of the percentage of heat utilized under a boiler when burning oil or coal will hold good when diffused in and through a kiln of brick. I do not think it will, for a kiln seems to take up all the heat of combustion in either case, certainly until the last stage of burning, when the blanket of steam ceases to hold down the heat as in the earlier stages, a condition very different from the smoke-stack of a boiler.
"Wood is the simplest and most expensive fuel in most localities, certainly in localities where the greatest number of brick are made, but between coal and fuel oil it is an open question yet to be determined which is the better, by a longer and more thorough test.
"I have used coal at a cost of about 50 cents per 1,000, and am now trying oil in the latter stage in burning to get a larger volume of heat and to deepen the color of the brick when burned. We have just finished burning a kiln of 19 arches, containing 451,000 brick, using 67 tons of coal at $4.25 per ton, making the cost per thousand 634 cents. This kiln of 451,000 brick contains 15 tons of coal-dust as against 18 tons in the same number of brick made last year. This amount and the height (six brick higher than last year) may account for the longer time and greater relative consumption of coal than usual ; two hands do the work. We set 52 brick high to econ omize the shed room, but are satisfied that 46 high is better and more economical.
Mr. D. V. Purington, of Chicago, Ill., said at the third annual convention of the National Association of Brickmakers " I have burnt this year, 1888, a little over 28,000,00o brick with out using a stick of wood or a pound of coal—entirely with oil. Of course, my brick are artificially dried. We have taken out of each brick, from the time it was made till it was set in the kiln, a pound and a quarter of water, so they are when set about as dry as can be got, practically. We start one side of the kiln three or four hours before we do the other, and we get the heat up just as fast as we can get the draft started. When we first start, of course, without the arches being heated at the sides to form a combustion, we have to burn more oil. Our fuel is oil, and we burn on an average four days, where the average was about seven days and a half before. The kilns
used are 24 arches each, and where we used five men before we now use two. There are no ashes to haul away, no coal to unload. Our fuel is unloaded with a little steam pump, and it is then ready to be drawn by gravitation from the tank to the kiln. I can state unequivocally that I know of no inducement other than a pecuniary one, that would lead me to go back to burning common brick, artificially dried, with wood or coal. I'm not up on heat units, and shall endeavor to talk in a lan guage that brickmakers can all understand. I don't know a unit of heat ; wouldn't know a dozen if I should see them right here. The cost of fuel has been, for oil, an average of 36 cents per 1,000. Before we understood oil and its uses, we used a great deal more than we do now, and we are all the time improving upon it. Any science so new as the burning of brick with crude oil is susceptible of great changes, and I expect it to improve for the next ten years. The exact total cost of burning brick so far with me, I have been unable to as certain, for this reason—I take my steam from a stack of three boilers, and the same steam from the three boilers is used for running my machines in the day-time and also for my kilns, and for burning brick ; so I have been unable to divide the amount of steam used for burning brick, and the only way I can get at it is relatively, and my figures show the total cost for labor, fuel, oil, and coal for burning brick this year has been cents, as compared last year with 92 cents, when using wood and coal.
"If the cost of fuel was the same, if it cost me just as much for oil and wood to make steam as it did for wood and coal, I would still burn with oil. My arch brick, aside from the first 18 inches, are the best I have in the kiln. There isn't a check end brick or discolored brick, or anything that would damage them ; they are really the best in the kiln.
"To use a burner with an aperture sufficiently small to make a light fire results in clogging that aperture with carbon. The hydro-carbon burner made in New York, and which Mr. Smith represented last year, is in many respects, I think, the most complete oil-burner I have ever seen. There were five aper tures about the size of a knitting-needle in that burner.
"The first three kilns we burnt we had a good deal of diffi culty in handling our fires with oil and getting the centres and outside corners and ends hot, and in throwing the heat to any part of the kiln desired ; but now to get the heat we let one side go very light and fire the other heavily, so that the two flames, instead of meeting in the centre, face, just as in the old fashioned way. I can get any heat I want inside of two min utes. We use slack coal on the outside courses. After start ing the fire, and the brick begin to sweat, which all brick will do, there is no difficulty in getting the fire up through them; and there is one advantage in the use of oil over the use of coal : in forcing your fire it is an absolute impossibility to choke your kiln with oil, and you have no ashes, no dust."