RECENT PROGRESS IN GAS ENGINEERING.

At the recent meeting of Scottish gas managers Mr. A. Macpherson, of Kirkcaldy, the chairman, said:

THE REGENERATIVE SYSTEM OF RETORT FIRINGS.

For me to attempt, with the time at my disposal, to do full justice to many important points which have cropped up since our last meeting, and which will, no doubt, have been engaging your individual attention, would be impossible. But I think there can be no doubt that, although at our last meeting we had a very full and interesting discussion on the different systems of regenerative retort settings, still we might very profitably spend a little time to-day in hearing the experience of those who have had some of the systems introduced into their works since then, or who may have gained further experience with the system they were then working, or have introduced improvements or modifications thereon.

For the purpose of inducing a discussion on this subject, I will give you the result of the working of the bench of retorts which I erected three years ago on the Siemens system. As I stated last year, my experience up to that time had not been altogether a happy one, but one of sunshine and cloud alternately. I am glad to be able to say, however, that since then I have had nothing but the utmost satisfaction in the working of the regenerative settings. The chief difficulties I have before experienced were of a mixed nature--choked ascension pipes, entailing considerable loss of gas; the choking of the orifices from which the secondary heated air issued to join the producer gas; and the eating away, in a "scooped-out" sort of fashion, of the brick lining of the producers at the points where the primary air entered. These, I am pleased to be able to say, I am now completely clear of; and this has had the effect of converting what was before a considerable source of annoyance and anxiety into as perfect a working bench of retorts as any one could desire.

The results I have obtained have caused me much surprise, being far in excess of anything I ever anticipated; and the saving effected will materially assist in compensating for the greatly reduced value of residuals. I may state that I have used 30 per cent. of fuel on an average, saved from 25 to 30 per cent. on stokers' wages, and increased my production of gas per ton of coal; while the regularity of the heats was a pleasure to look upon.

As showing what I have been able to accomplish, I will give you a few details. I was able regularly to produce 10,000 cubic feet of gas per mouthpiece in 24 hours--the size of my retorts being 18 by 13 inches by 9 feet long, inside measure; and on a sudden dullness coming on, with an increase of first class cannel I produced from 33 retorts 357,000 cubic feet, or at the rate of 11,500 feet per mouthpiece in 24 hours. With 32 retorts I made as much gas as would have required 42 retorts to produce on the old system. But I know that even this can be excelled; and I am aware that there are works where, by the introduction of retorts measuring 21 by 15 inches, instead of 18 by 13 inches--and which, I may say, can be put quite easily into the same arch--a production of 12,000 cubic feet per mouthpiece can be obtained. This will, of course, still further reduce the cost of production.

With such an experience, gentlemen, I think it is almost needless for me to add that I am a strong advocate of the regenerative system. I have often heard it asked, "But can the system be profitably adapted to small works?" In answer to this, I will say I have proved that it can. During last summer the manager of a small gas works in my neighborhood called on me regarding the working of this system, and expressed a desire, if it was at all possible to adapt it to his present settings without much expense, to try it. I must say I admired his progressive spirit and pluck; and, after a somewhat lengthy conversation with him, during which I gathered the full details of his working and his requirements, I determined to encourage him in his desire to prove if it could be successfully applied to a works of the size mentioned. The present setting consisted of three retorts in one arch; and one of his stipulations to me was: "You must so contrive the setting that if it should prove a failure I can reconvert it into the old system in a few hours." I at once saw that the stipulation was reasonable, or he might be caught in a fix in midwinter. But, with true "Scotch caution" and forethought, he was, while anxious to experiment, determined not to be "caught napping." After some consideration, I prepared a sketch for him of how I thought it could be done, and at the same time comply with his stipulation; and having received full explanations, he set about it, and has had it working now for something like six months. His experience has been somewhat similar to that of most of those who have gone in for the new system. It did not answer very well at first. But after a little manipulation and experience in the proper working and management, it is now acting in first rate style, and is saving fuel, with better and more regular heats; and this although it is not constructed in such a way as to yield the best possible results, owing to the before mentioned stipulation having to be considered and allowed for in construction.

In answer to an inquiry I made the other day, the gentleman referred to informed me that he has now had this setting in operation for six months. He has three retorts, 14 by 16 inches, and 8 feet long, in an oven carbonizing 2 cwt. of coal every four hours; the heats are higher and more regular; and the retorts easier kept clear of carbon. The coke drawn from the top retort is sufficient for fuel. My oven would hold four retorts; and the same fuel would heat this number just as well as the three. I used only the coke from Cowdenheath parrot coal for this setting; but had to mix it with Burghlee coke for the old system of setting.

No doubt most of you will have noticed the satisfactory results obtained by Mr. Hack, of the Saltley Gas Works, Birmingham, and by Mr. McMinn, of Kensal Green, with the furnaces employed by them for gaseous firing without recuperation, whereby they are enabled to save fuel and carbonize more coal per mouthpiece than with the old system. Still they admit that the saving by this setting is only in fuel, with increased production, but without any economy of labor--one of the points in favor of regenerative setting being a saving of at least 25 per cent. in the latter respect. Even where regenerative settings cannot be had, I think the system of using gaseous fuel is well worthy the attention of managers; the expense of altering the existing settings to this method being very small.

IMPROVEMENTS IN GAS PURIFICATION.

I must now, however, pass on to some other topics. After the proper production of the gas, we have still the processes of purification to consider, and how this operation can best be effected at the smallest cost, combined with efficiency and the least possible annoyance to residents in the immediate vicinity of gas works. I think all gas engineers are agreed that in ammoniacal liquor we have a useful and powerful purifying agent, although each one may have his own particular idea of how this can be most efficiently applied--some advocating scrubbers, others washers. But these are things which each one must determine for himself. But in whatever way it is applied, we know that it can be profitably used for this purpose; and I am not without hope that it may soon be found possible to remove nearly all the impurities by this means.

At present, however, this is not so. And consequently we have a variety of other methods employed for the complete removal of the impurities. But, by whatever means it is effected, it is unquestionably the duty of the gas engineer to send out to the public an article from which the whole of the impurities have been removed.

In Scotland, no doubt, our chief purifying material is lime, although I know that several of our friends have for some time been using oxide of iron, and perhaps they will favor us with their experience and a statement of the relative cost of lime and oxide. I am not aware that either the Hawkins method or the Cooper coal liming process has yet received a trial from any Scotch gas engineer.

BURNERS AND REGENERATIVE LAMPS.

But even after we have been able to produce and send out gas of the greatest purity, our troubles are frequently only beginning, as, very often, consumers do not use, but simply waste and destroy the gas by bad burners and fittings. Nothing, however, will convince them that they are in any way to blame for the light being poor. I am certainly of opinion that gas companies would do the public a service in supplying them with suitable burners for the quality of gas that is being sent out for consumption. I have myself for some years adopted this policy, and almost invariably find that complaints cease and consumers are pleased with the results.

We have now also so large a number of really good regenerative lamps which give excellent results, and can be made in a great variety of very neat and ornamental designs, that we ought to endeavor to the utmost of our power to introduce them to the public, and, if possible, induce them to use them not only in halls and similar places, but in their dwelling houses, as with these lamps a most thorough and efficient system of ventilation can be carried out, by which the heat that is so much complained of in gas-lighted apartments is reduced to a minimum, and the atmosphere of such apartments is rendered healthy and agreeable.

With such improved lamps at our command, I think we have nothing to fear from the competition of the electric light, which during the past year has not made any very startling advance--generally attributed by electricians to the restrictive legislation under which they have been placed. Let us hope this is now about to be removed. I am sure we all rejoice that such is the case, as all we want is a "fair field and no favor." We can with confidence await the result.

THE WELSBACH GAS LIGHT.

In the mean time, however, while electricity for lighting purposes has, to say the least, not made any startling advances, we have, besides the regenerative lamps before mentioned, the new Welsbach light, which is exhibited before you to-day, by the kindness of Dr. Wallace; and if the results said to be obtained by it are at all what they are represented to be, we certainly have a new departure in gas lighting of no mean order. Dr. Wallace--a gentleman who is well known to us as one well qualified to test its merits--has found that the Welsbach burner produces a light equal to more than 9 candles per cubic foot of gas of 25 candle power, thus nearly doubling the amount of light compared with gas consumed in the ordinary way.

The construction and manufacture of the burner I have seen described in these terms: Chemists have been diligently working for many years on the problem of how to convert into light the highly condensed heat of the Bunsen burner; and a Vienna chemist now claims to have solved it.

The first condition of the problem was to find a medium on which the heat could be perfectly concentrated and raised to illuminating power. Many experiments have been made with platinum in a Bunsen flame, and a brilliant enough light has been produced, but at a cost altogether outside commercial use. The Vienna chemist, Dr. Welsbach, has discovered a composition which is as good a non-conductor--that is to say concentrator--of heat as platinum, is much more durable, and a great deal cheaper. The base of it is a peculiar clay, found in Ceylon, which combines the indestructibility of asbestos with the non-conducting property of platinum; and having found the incandescent medium, he has next adapted it to the Bunsen burner.

In this arrangement there is the simplicity of genius. He gets a fine cotton fabric woven into the shape of a cylinder, with a tapering point. In its first stage it is about 2 inches in diameter; and after being coated with the composition, it is subjected to a strong heat. This has two effects--first, the cotton fiber is completely burned out, while the composition retains the shape of the woven surface on which it was moulded. Then the cylinder contracts and solidifies until it becomes about the size of the forefinger of a glove. Dr. Welsbach calls this his "mantle;" and by a simple arrangement he fits it on a Bunsen burner, and places an ordinary lamp chimney over it. When the flame is applied, the "mantle" becomes incandescent, and gives out a brilliant yellow light, which, it may be said without exaggeration, will compare favorably with any electric light yet put on the market.

For decorative effect a pretty frosted globe is used; and by varying the globe a pure white or a pure yellow may be obtained. It is also added that there is no act of Parliament required for it, nor even a provisional order of the Board of Trade. No streets have to be broken up in order to lay down pipes; and no wires have to be hung across the roofs of protesting householders.

The whole apparatus can be got ready to fit on an ordinary gas bracket; and two or three spare frames with "mantles" can be kept in the house in case of accident. Whoever sees the Welsbach incandescent light in operation will readily admit that it is the "coming light." It has beauty, brilliancy, purity, and economy all on its side.

Let us hope (added the chairman) this description is not overdrawn; but of this you will later on have an opportunity of judging for yourselves. No doubt the general or even partial adoption of this light would have a tendency to reduce the consumption of gas, as a smaller quantity would be required to produce the same amount of illumination. Nevertheless, gas engineers will hail it with approval if it in any way tends to popularize the use of gas, and helps to increase the comfort and improve the sanitation of our houses, churches, halls, etc. Moreover, gas is continually being adopted for fresh purposes; and we can confidently look forward to an almost unlimited field in the rapid and ever increasing use of gas as a fuel and for cooking purposes, as well as for motive power. The new and really excellent gas engines now being brought into the market will, no doubt, create a healthy rivalry, and tend to cheapen these useful machines, and so bring them within the reach of many persons who have hitherto been prevented from employing them by their considerable first cost.

PARAFFIN AS A RIVAL OF COAL GAS.

But while the day has gone by when any one of us fears the electric light as a possible rival, we are not insensible to the fact that paraffin oil, from its present low-price, is a rival which we cannot afford to despise. And more especially is this the case in many of the smaller towns and villages, where the charge for gas is of necessity higher than in the larger towns.

Doubtless, with oil there is not the same cleanliness as with gas; while there is also more trouble, attention, and considerable danger attending its use. Still, in these "hard times," most people are inclined to adopt the cheapest article, even at the cost of these drawbacks, so as to make their money go as far as possible.

But not only as an illuminant is it being brought into direct competition with gas, but also as a fuel and for cooking purposes, as well as for motive power. And I am inclined to think that the sooner we set about trying to solve the problem of how to meet this new competitor, the better.

OIL IN GAS MAKING.

A new departure has also recently taken place in the adoption of oil for gas making purposes. This, of course, is more fraught with danger to the coal master than to gas companies, inasmuch as, should this prove to be a more economical raw material from which to produce illuminating gas than coal, our present coal gas works could be easily remodeled and turned into oil gas works. This process has recently been introduced into a village in Fifeshire. And I have made it a point to visit and inspect the works, which have been converted into an oil gas works, so that I might be able to lay a few particulars before you. The process, however, has not been in operation long enough to enable me to give you much information on the subject, especially in the way of details of cost, working expenses, or permanency of the gas under varying and low temperatures. The patentees claim that they can produce 100 cubic feet of 60 candle gas from a gallon of oil, or at a cost of 3s. 11d. per 1,000 cubic feet for oil, fuel, and labor; no more expense being incurred, as the gas does not require purification.

At Colinsburgh (the village alluded to), I was informed that the man sent by the patentees could produce 100 cubic feet of gas per gallon of oil; but they had no means of testing the illuminating power. The gas company's own servant, however, only produced 80 cubic feet per gallon, which they attributed to his want of experience in knowing the proper heat at which to work the retorts. Whether or not this was so I cannot tell; but of this I am certain, that the statement made that the gas does not require purification will not bear investigation. When I tested it for sulphureted hydrogen and for ammonia, both were indicated in such an unmistakable manner as none of us would care to see in our coal gas as sent out to the consumer.

PRICES OF RESIDUAL PRODUCTS.

What is of far more real consequence to us than the possible change from coal gas to oil gas, however, as long as we remain manufacturers of the former, is the value of our residual products, which has suffered so great and sudden a decline in value, for which various remedies have been proposed, though none of them, I regret to say, have as yet restored anything like the former value. A statement of the highest prices realized for coal tar products, and a comparison with those obtained on the 30th of March last year and at the same time this year, may not be uninteresting:

This shows a great fall in value from highest to lowest, which seems to have been touched last year, except in the case of pitch and sulphate of ammonia, both of which have marked a considerable decline, even since last year, but it is pleasing to note that the others have shown at least some slight improvement--crude naphtha and benzol having during the year risen nearly one hundred per cent. in value. Let us hope that this is the precursor of a general rise in value from which we shall all profit. For the purpose of bringing about this much desired end, I understand that some of the gentlemen present to-day have been burning their tar in the retort furnaces, and as it will be interesting to know what success they have attained, I hope some of them will favor us with their experience on this subject.

In conclusion, let me express the hope that the time is not far distant when the general trade of the country will attain to its wonted prosperity, by which every branch of industry will benefit--ours among the number; and that the hard times we have experienced, now for a considerable number of years, may not again return.

Discussion next took place regarding the Welsbach incandescence gas light, which was opened by Mr. McGrilchrist, who remarked on the very fragile and tender nature of the "mantle," and expressed a hope that in this direction improvement might be looked for. It was certainly a beautiful light, and as to its consumption, he stated that the lamp then shown to the meeting was only burning two cubic feet of gas per hour. [A voice: Two and two-tenths.] He felt satisfied that it would enable the manufacturers of gas to compete with paraffin oil, so that with Glasgow gas they could have such a light as they saw at the rate of 4d. for about fifty hours.

Mr. W. Key (Tradeston Gas Works) made a statement giving the results of inquiries he had made at St. Enoch Station Hotel, where the light has for some time been on exhibition. From the answers given to his inquiries he spoke rather disparagingly of the lamp, but chiefly on account of the expense involved in renewing the "mantles" and the glass chimneys. He admitted, however, that the lamps which he had seen were placed very unfavorably, being exposed to the action of somewhat violent draughts, and he subsequently remarked that the lamp was of such a nature as to effect the complete combustion of the carbon contained in the gas. The burner must, therefore, be regarded as a great boon--as the burner, in short.

Mr. D.M. Nelson (Glasgow) gave his experience gained in connection with the light, remarking that one of the great drawbacks to it was the very great rarity of the mineral from which the zirconium was obtained. So scarce was it that it would become dearer than platinum and more valuable than gold if the lamp came into general use. The light which the lamp gave out, though it possessed intensity, was deficient in diffusibility as compared with that given out from ordinary flat flame gas burners, and this was another objection to it. He argued at some length against the financial aspects of the scheme which was being promoted to buy up the Welsbach patents, and to introduce the lamp into this country. His advice to his friends was not to have anything to do with the Welsbach company, and, as investors, to be very careful in accepting all the statements made about the light, which he predicted would not be a financial success.

Mr. McCrae was strongly opposed to any discussion being raised in regard to the question being considered in its financial aspects. They, as gas engineers, did not require to trouble themselves with the doings of investors. He regarded the Welsbach burner as an improved appliance for consuming gas. It was an invention which was quite new to him, and as he was not in possession of any facts which would enable him to condemn it, he thought they ought, at least, to give it a fair trial. Referring to the fragile nature of the "mantle," he remarked that there were minds at work aiming at giving a purer and more brilliant light from gas, and so far he was of opinion that the light before them was a success. His opinion as to the diffusibility of the light emitted from the burner differed from that of Mr. Nelson, as he considered the light possessed that quality in a high degree. He had no doubt that the minds already at work on the incandescent light would seek out means for improving the burner.

To varnish chromos, take equal quantities of linseed oil and oil of turpentine; thicken by exposure to the sun and air until it becomes resinous and half evaporated; then add a portion of melted beeswax. Varnishing pictures should always be performed in fair weather, and out of any current of cold or damp air.