pencil. In the illustration given by President Morton, the ends of those carbons were extremely beautiful. They had the appearance of the top of a mountain covered with snow. As the light played from side to side, it would appear like a mountain on one side, all shaded, but the shadow would pass to the other side, showing that these particles of carbon were being torn off at frequent intervals. In the incandescent light the trouble seems to be of a different character. Of course, the question still arises as to the quantity of electricity required to produce the light, and the intensity. The trouble that I have observed in all companies that I am connected with (notably at Woburn, Mass.) is that the lamp itself degenerates. We do not observe this in a great city like New York; and there are two or three reasons why we do not observe it here. One reason is that all the apparatus used for the purpose of producing incandescent light is new, and the various manufacturers are naturally very ambitious and anxious that their light shall make a good show here so that they may introduce it elsewhere. There is another reason they can employ special electrical talent here; and it does not so much matter to them here what the light costs. In order to get at what the incandescent light will do on the average, you must go to some small place, like Woburn, for instance, which is still a town, although it aspires to be a city. There we find in practice that the electric light company, which is competing with the gas company, is offering to supply electric light to any store at the price of gas. The first lamps they put in give a 20-candle light, which is better than our gas light, the latter averaging from 161⁄2 to 17 candles. But the character of that electric light gradually degenerates, until it gets down to 8 or 10 candles; and there it stays. That amounts to a serious fluctuation in the long run, and is a matter which, in the hands of outside companies (not gas companies, who have studied this subject in the way of looking after their consumers and rectifying evils), amounts to an evil sure in the long run to be very vexatious. If you will take the readings of your photometer often enough, after your gas is ready to go into the holder, and see to it that your consumers are not using worn-out and wasteful burners-a matter that every company ought to look afterthen I make the claim that, month after month, and year after year, we have, in gas, a more uniform lighting value than can be shown in any other known method of artificial illumination. On motion of Mr. King, a vote of thanks was tendered Mr. Monks. THE PRESIDENT-As the next two papers to be read are on kindred subjects, we will hear them both read before we discuss them. Mr. O. B. Weber, of New York city, read his paper, entitled: DEVELOPMENT OF THE HALF-DEPTH REGENERATIVE FURNACE, AND SOME OF THE RESULTS. Firing retort benches with gaseous fuel has occupied the attention of the gas world for the past 25 years. As practical results of these labors, the various regenerative systems show how much ingenuity and scientific learning has been expended. The first attempt to fire with a regenerative adjustment in this country was made at the 42d Street Station of the Consolidated Gas Company, New York city (known then as the Metropolitan Gas Works), and was due to the progressive and enthusiastic ideas of the President, Mr. O. Zollikoffer. The form of furnace used was the Liegel, or Slit, which enjoyed at that time the privilege of being the first regenerative furnace tried in this country. This system, through the untiring and zealous devotion of the late Mr. Herzog, the engineer of the works, after several alterations, made necessary by the difference in the fluxing quality of European and American coke, has maintained itself at these works with great success. The next departure was the substitution of a grate furnace for the slot, suggested by Mr. Alexander Strecker, engineer of the works at that time. This change showed conclusively that, as far as this country was concerned, the most successful furnace would be one with a grate. This · was the turning-point in the use of this system. It became apparent now, through the successful operation of these furnaces, that, if not too costly in construction and elaborate, nor requiring any more than ordinary care to run them, they would become valuable adjuncts to small gas works. It seemed a comparatively easy matter to translate a Liegel furnace to any gas works in the country. In one's mind, perhaps, this was so; but, practically, alas! What insurmountable and fearful obsstacle were in the way! My friend, Mr. Baxter, had low retort houses and chimneys; Mr. Sherman was not able to excavate any distance below, owing to attraction of the waters of the Sound; another well-known gentleman discovered an iron spring bubbling forth in one of his arches, after digging down a few inches below the floor-line, and so I might multiply the cases, almost ad infinitum. It was all very well to speak of raised iron floors and charging platforms; but fate, in the shape of a stern Board of Directors, often withheld its sanction, scared by the increased cost of building. It was necessary in order to obtain the advantage of regenerative firing, to construct a furnace possessing all the cardinal features of the large one, without its elaboration or depth. Opportunity soon offered itself, through Mr. A. C. Wood, of Syracuse, N. Y. The half-depth furnace placed in his works was the first trial of this system. It possessed all the features of a large furnace together with its weak points. The air for primary combustion was taken in directly under the grate bars, without previous warming. The height of the combustion chamber was very small, so that scarcely any very important results could have been looked for from it. Still, it served as a guide; and subsequent trials show that the lines of construction as laid down in that furnace were correct and permanent. The practical application, now, of this system on a larger scale-i. e., under many benches in one stack-was made at the works of the Williamsburgh Gas Light Company, Williamsburgh, N. Y. The enterprise of Mr. C. W. Blodget made this trial possible. A stack containing 20 benches of six retorts each was erected. The details of this plant may interest the gentlemen of the Association. To begin with: The depth below the floor-line is 30 inches. The arches are 7' 6" wide, and 10' long, accommodating retorts 14"x28"x10'. The benches are built back to back, and the draught for them is furnished by one main flue running below the entire length of the stack to a chimney 75 feet in height. This does away altogether with the chimneys on each bench, affording a steady and uniform pressure on each bench. It will be assumed, naturally, in working regenerative furnaces, all that is to be done is to fill and light the furnace, then charge the retorts and expect 9,000 to 10,000 cubic feet yield. This is all very nice; but it takes a little persuasion to secure this. Before getting there, however, make up your mind that it will not all be easy work. The presence of clinker, hard enough to build houses on, soon manifests itself. An increased consumption of coke surprises and alarms you. To make matters worse, the heats, of whose uniformity and regularity you have been led to expect so much, go down, so that hardly 200 pounds of coal can be carbonized. Speculations as to the probable cause are numerous, and pet theories are manufactured to suit the case. Experience similar to this has been frequent, but the causes producing such effects have been discovered, as well as the way to avoid them. In the first place, the passage of the products of combustion through the parallel flues to the chimney is at times interrupted by a hard metallic clinker depositing itself in the last flue. Why it should remain there is obvious: carried around in a highly heated condition, the infusible particles of the coke are in suspension until the vertical or chimney-flue is reached. Then their specific gravity prevents them from ascending; and, gathering additional volume, soon the most beautiful and exasperating clinker ever seen is formed. To obviate this becomes, then, a prime necessity. This is partially accomplished by heating the primary air supply, as well as permitting it to come to the grate-bars at ordinary pressure. An important feature, also, is the draught on the bench. There must be no rush of air, either primary or secondary; but all of it must go in easily and naturally. In fact, the damper on the bench chimney should not be opened any wider than to insure an easy but constant draught. Since the time this fact was established clinker has troubled us but little. The relation of the supplementary air supply to the primary oftentimes is a perplexing factor to the men in the retort house, or until they have become accustomed to the working of the furnace. It is a safe rule when employing an ordinary bench chimney furnishing through draught, to open the primary air supplies all the way and the secondaries about half. The area of each slide is 25 square inches. When the furnace is once in working order the men in the retort house find no difficulty in running it successfully. At first they generally express some doubt as to the ability of the furnace, but when they see that it lessens their labor, besides doing away in a great measure with stopped standpipes, there is a rush for the position of fireman. In small works, with an output of only 20,000 cubic feet per day, the saving of labor to the man in charge is quite a factor. The uniformity of the heats carried, and the comparative ease with which the furnace can be run, invite inspection. The percentage of the saving in coke is much higher than expected, and the average yield per mouthpiece compares favorably with the average results of the deep furnaces. I am indebted to Mr. Blodget of the Williamsburgh Gas Light Company for some of his results obtained during this season's run. In retorts, 14" 4"x28"x10', charges averaging from 280 to 300 pounds have been burned off every four hours, with an expenditure of about 25 per cent. of the coke made, figuring 40 bushels to a ton. The general averages of the various "furnaces in other cities show, besides the marked saving in coke, an increased output per mouthpiece, as well as a decrease in the wear and tear of the furnace and retorts. If, perhaps, the half-depth furnace as at present built does not pave the way to "Dollar Gas," it is not the fault of its economizing qualities. Mr. Fred Bredel, of New York city, then followed with a paper on THE ADVANTAGES OF REGENERATIVE FURNACES FOR LARGE AND SMALL GAS WORKS. Gentlemen of the Association: Every gas engineer will admit, in a general way, the advantages of regenerative furnaces, but my present purpose is to show to you in a specific way the financial advantages secured by their use. Take, for example, the case of a large gas works, in which the retort-house is fired under the old system, and that the plant is still in good or perfect working order. To replace it with the improved style of furnace would cause, say, a total loss of that which it succeeded. Assuming that to be so, and the maximum production to be estimated at 1,300,000 per diem, with the total annual output fixed at 300,000,000 cubic feet, such a condition of things would call for a retort-house containing fourteen benches of 9's, the cost of which would be about $84,000. At the start, then, we are obliged to charge $5,040-$84,000, at 6 per cent. per annum to interest account. Now, we could carbonize 60,000,000 pounds (30,000 net tons) of coal per annum, and have left for - |