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which has been found to agree with the experiment was not made from any motives of economy ence of others who have given attention to the subject; that any plan requiring additional attention on the part of the stoker-such as the opening or closing of air-valves- or giving him extra labour, which was required in some cases, was found in practice to be unsuccessful, although a single experiment, carefully conducted, might seem to prove the contrary.

In 1847 the writer's attention was first drawn to Jucke's Patent Furnace, which consists of a strong cast-iron frame of the full width of the furnace, and about three feet longer. The firebars are all connected together, forming, when complete, an endless chain, and are made to revolve round a drum, placed at each end of the frame. The front of the frame is provided with a hopper, in which the fuel is placed, and a furnace-door, which opens vertically with a worm and pinion. The height to which this door is raised by the stoker, regulates the supply of coal, which is carried into the fire by the gradual motion of the bars. The whole machine is placed upon wheels, to facilitate its removal for repairs to the boiler, brickwork, or furnace. The speed of the furnace-bars is determined by the draught. It varies from one inch and a half to three inches per minute, the object being to keep the whole of the bars covered with fuel, with a small accumulation of fire at the bridge. The bridge is suspended by a pipe three inches or four inches in diameter, fixed about one inch above the level of the bars; this allows the clinkers formed to fall into the ash-pit, but will not allow the fire to pass. A small stream of water must be supplied to the pipe or stop, or it would soon be destroyed. All the air admitted to the fire to support combustion, is made to pass through the furnace-bars. The consent of Messrs. Truman, Hanbury, Buxton, and Co., was obtained to the application of this plan to one of their engine-boilers-a cylindrical boiler, with two tubes-driving a forty-horse engine. It is due to them to state that the costly experi

in the first instance. Its success led to its application to a second boiler of the same form. In the same year the probability of its success under a brewing copper was discussed. There was no doubt, from the former experiments, as to its capabilities for raising steam or for evaporation; but with a brewing copper provision had to be made for a process in the manufacture almost peculiar to it. The contents of the copper have to be turned out several times in the course of a brewing, rendering it necessary to "bank up" the fire thoroughly, to protect the bottom of the copper, until refilled with wort or water. It was feared that the machinery would interfere with this being done effectually it was tried, and with the same success as with the steam boilers. It was found that a fire of fifty feet or sixty feet area, could be worked for any number of hours, without the slightest appearance of smoke from the chimney-shaft; but the process of "banking up," before referred to, required the whole principle of the machine to be put in abeyance, during which time smoke escapes from the shaft, sometimes in large quantities, and no plan has been discovered for its prevention. Considerable difficulties were encountered in the application of the principle to the furnace last-mentioned. Owing to no provision having been made for its great size, the side frames and the drivinggear were too weak, and the machine generally was imperfectly put together. The stop carrying the bridge gave a great deal of trouble. All these difficulties were, however, removed by experience; the frame was strengthened, the furnace was re-made with greater exactness, and an important alteration was made in the drivinggear, which was removed from the side of the furnace, attached to a small crab-frame, and connected to the former by a small intermediate shaft. The "banking up" was found to be as effective as with the old bars. The remainder of the coppers and boilers were afterwards altered, as shown in the following table :

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The total cost of the fourteen furnaces, including brick-vention of smoke, for he has reason to believe that the work, has been about 3,000. The consumption of coals eminent firm of Messrs. Price and Co. have been equally in the establishment is about 6,000 tons per annum. The successful with other plans as well as with the one to saving in the coal account, since the introduction of the which he has drawn attention; but he has confined his patent furnaces to July 1st of the present year, has been remarks to his own immediate practice, leaving inventors as follows:and others to give the result of their own experience.

July 1, 1848, £69

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From which is to be deducted for casualties, which have been referred to, and sundries, say 350l. The above economy has not arisen from less weight of fuel consumed, but owing to the screenings or dust of coal only being required for the furnaces. Should the difference of price between large and small coals be reduced, the economy will be less in future years. There is a considerable loss in weight in using the dust of coal, but the following extract from a report by Messrs. Easton and Amos, who have made some interesting experiments with one of these furnaces, shows a saving of 11 per cent. in weight of fuel, when the ordinary steam coals are used. They say "the boiler with which the experiment was made is of a cylindrical form, with spherical ends (without tubes); its length is 20 feet; diameter 4 feet; and when used with the common furnace, the rate of evaporation was 7.73 lbs. of water by the consumption of 1lb. of Ord's Redhugh coals. We began to make experiments to ascertain the exact degree of saving effected by the patent furnace on the 12th of September, and continued them throughout the week, the engine working 62 hours. During this time we evaporated 47,520lbs. of water by the consumption of 5,488lbs. of Ord's Redhugh coals; the cost of which was 17s. 6d. at the furnace mouth. The evaporating power in this case is equal to 8.65 lbs. of water with llb. of coal, being a saving in fuel of nearly 11 per cent."

It will be noticed in the Table of Furnaces erected at the brewery, that a considerable reduction has been made in the area of all the new furnaces, varying from 20 to 30 per cent. with an increase of water or wort evaporated of 15 per cent. in one of the large brewing coppers. This arises from the fire-door not requiring to be opened, and from the movement of the bars which prevents any scoria stopping up the air spaces of the fire. It will be evident that this plan, which has been successful on land, would require some modification to make it equally so on the water. M. Tailfer, of Paris, in 1845, gave his attention to the subject, and the French government placed a steamboat at his disposal for the experiment.

It would appear at first sight that the wear and tear of a machine, apparently so complicated, must exceed the expense of the common fixed bars. This, however, has not been found to be the case, and it need not be so if ordinary care is given to the machine, and a periodical exexamination is made, such as any other machine of equal value and producing equally important results would receive. Within the last week a set of bars have been renewed, for the first time, which have been in use since May, 1849; and three fourths of the old bars are being again used for another furnace, where the boiler is of less importance than the one from which they have been removed.(a)

In conclusion, it must not be understood that the writer considers this the only plan for the combustion or pre

(a) During the four and a half years, about 18 tons of fixed bars would have been used, which at £8 or £9 per ton, would leave a considerable margin for repairs. It should be stated, at the same time, that there are facilities for repairs at Messrs. Traman's which many others have not, workmen being always on the premises ready to execute them.

DISCUSSION.

Mr. JOHN LEE STEVENS said, he could not venture to open the discussion, without bearing the strongest testimony to the ability and integrity of purpose which had been shown by Mr. Fraser. All inventors of smokeconsuming apparatus were indebted to Mr. Jucke as a great pioneer in their cause, and if such constructive genius had not been exhibited by him, the public might have waited a long time before the smoke nuisance would have been abated by legislative enactments. But not only was the inventor to be thanked, but thanks were also due to Messrs. Truman, Henbury, and Co., for the manner in which they had disabused the public mind of the impression that the smoke from furnaces could not be prevented. He (Mr. Stevens) was himself an inventor of a means of consuming smoke, but he would not allude to the circumstance further than to state, that, judging from the pressure of work on his hand, there was ample room for twenty inventors. If he understood the matter at all, he thought the vocation of inventors was not to find fault with each other, but to sustain each other. Besides the invention of Mr. Jucke's, there was one equally clever by Mr. Samuel Hall. The machines invented by both of those gentlemen were moveable machines, but if a more simple and less expensive and pretending apparatus were required, he would be happy to exhibit his; and if it was not approved of, there were many others in the field from which a selection could be made. He thought they ought to put the public in the best position to judge for themselves. In reference to the invention which had been brought forward on this occasion, he contended that it had not been shown that it was anything but a slow combusting apparatus. It had not been shown that it was equally applicable to all purposes, fot getting up steam to a higher power than usual, or for any other exigency. It had been stated that the saving in fuel by the substitution of slack coal was considerable, but he (Mr. Stevens) had been disappointed that the saving in the consumption of coal that actually took place, was not greater than had been stated. He expected Mr. Fraser to have said, that the saving in fuel would have approximated 20 per cent. Mr. Fraser had also said, that the highest evaporative capacity was 8.61b. of water to 1lb. of coals. This was the only good test for ascertaining the capability of a furnace. With respect to his own invention, he had applied to the eminent firm of Messrs. Easton and Amos, seven or eight months ago, to induce them to take it up, but they said they preferred a moveable to a fixed apparatus, and that they had no faith in his invention. Notwithstanding this he was happy to say that one of his furnaces was now burning on their premises, side by side with that of Mr. Jucke, and that the comparison was not unfavourable to the less complex and less costly machine.

Mr. TOMLINSON suggested that a definition of smoke was wanted. The expressions "consumption of smoke," and "prevention of smoke," were not very accurate, for, wherever there was combustion, there must also be pro ducts of combustion, and the visible portion thereof, or that which was commonly called smoke, was only one, and not the most noxious of those products. Smoke con sisted of nitrogen, carbonic acid, carbonic oxide, sulphuretted and carburetted hydrogen, hydro-carbons, vapour of water, and some other matters. The black visible portion was, chiefly, the carbon from the carburetted hydrogen which was decomposed by the heat, but, owing to a de ficiency of oxygen, did not undergo combustion, but was poured into the chimney, and so into the air in black, cloudy masses. The problem was to convert this visible

carbon into invisible carbonic acid; and, having done this, to trust to the diffusive powers of the atmosphere for getting rid of it. So long ago as 1785, Watt indicated the true principle on which this carbon was to be got rid of, and the smoke rendered invisible. His patent of that date was for constructing furnaces in such a way as "to cause the smoke or flame of the fresh fuel in its way to the flue or chimney, to pass, together with a current of fresh air, through, over, or among the fuel which had already ceased to smoke, or which was converted into coke, charcoal, or cinders, and which was intensely hot; by which means the smoke and grosser parts of the flame, by coming into close contact with, or by being brought near unto, the said intensely hot fuel, and by being mixed with the current of fresh or unburned air, were consumed or converted into heat, or into pure flame, free from smoke."

Mr. ECKSTEIN called attention to the valuable invention of Mr. Cutler, forty years ago, to consume the smoke in private houses. Mr. Cutler, however, had been unable to get a patent, as it was absurdly argued in a court of law that his invention was "not novel." About fifteen years ago Mr. Jucke thought he had discovered a machine applicable to private dwellings, but on showing it to him, he told him that he was twenty or thirty years too late, because Mr. Cutler had long since carried out the same idea. Mr. Juckes, however, like a clever, persevering workman as he is, went on, and ultimately produced the present ingenious machine. A friend of his had two of Mr. Jucke's machines at work, and he found that he saved forty per cent. in the price of his coals by burning small coals, and that of these he was enabled to use fifty per cent. less.

resumed. Any one who had taken the trouble to read the letter through, must have found this difficulty staring him in the face,-why, if this statement was correct, were not these furnaces in more general use. He would try to show reasons for this, in addition to those stated in the letter. Inventors (and being an inventor himself, and knowing the class well, he had a right to speak) were a most troublesome class to deal with; and the smoke consumers, with whom they had had dealings, deserved in this respect, to rank as highest of their class. Besides, the earlier-made furnaces were very imperfect. Jucke's bars were not deep enough, and therefore soon burnt through to the pins that connected them to the furnace sides; and these sides were too slight, the strength being put in the wrong place. Jucke's apparatus looked so pretty that they took it for granted that all its parts had been properly considered and calculated. It was not until two sides had broken down in the satne place that they looked into the matter, and added strength to the weak part. The sides and bars as at present made, were, of course, very greatly improved, and the furnaces were now quite successful. Mr. Hall, to the furnace he put up for them, added what he called a "boiler protector." This was so highly effective, that it not only prevented the boiler from burning, but prevented the fire likewise; the "protector" was soon removed, and a brick arch put in its place; the furnace then acted perfectly, and continued to do so to the present time. Hazeldine was equally judicious, but in a different way. He first put up his furnaces to work right, altered them to improve them, and so made them work wrong. The last furnace he made for them, however, he having profited by his experience, worked admi rably, and never got out of order. In some cases want of Mr. G. F. WILSON said, that as Mr. Fraser had referred capital, and in all cases want of business experience and to a visit that he paid yesterday to the works of Price's judgment in the inventors, had, he thought, been the Patent Candle Company, where he saw a large number of principal cause of the slow progress of smoke consmoke-consumers in successful operation, he, as a Director sumers; but there was another cause at work. The of these works, might perhaps be allowed to say a few words manufacturers who put up the first of the patent furon the subject. A fortnight back, on being applied to by naces had a direct interest in holding their tongues, the Secretary to the Society of Arts, he had noted down or, what they called in Scotland "keeping a calm sough." some of the results of their experience of three different The London small coals were at this time sold at about smoke consumers. When the letter was printed in the 4s. a ton cheaper than they would have been had furnaces Society's Journal, their people at Vauxhall said it was well adapted for burning them been more generally used; correct except as to the number of smoke-consumers, at Vauxhall especially, acting for many others as well as which was twenty-one instead of nineteen. The letter themselves, they had no right to make a stir, or to do should have expressed that all these smoke-consumers more than give such reports of the furnaces as the inwere under steam boilers. They had one sort of smoke-ventors had a claim to ask for. This year, however, circonsumer or other under many kinds of boilers, marine, cumstances had changed; on account of some small coalwaggon, Cornish, and cylindrical, with two tubes and the consuming furnaces being at work, and from other causes, fire underneath, but still they were under steam boilers London small coals had risen to even above their real only. Of brewers' coppers he knew very little, and had value. It seemed, therefore, that we must look in future never seen the bottom of one; but, from what he heard the to the north for our supply, and that the coming into other day, in conversation with one of the largest brew- general use of the smoke-consuining small-coal burning ers, he should suppose that they had difficulties to contend furnaces, as they would cause a larger demand, would with that we knew nothing of, especially in the necessarily make the supply more steady, and reduce rather than great size of their furnaces. It had been said that the chim- raise the price of small coal. He need not say what pleanies at Price's Works sometimes smoked. They certainly sure it gave him to have a hit, however humbie a one, at did a little, and for a short time, but the fault did not what was in some towns at least an utterly intolerable rest with the smoke-consumers. At the Battersea Works nuisance. they had many other furnaces connected to the same shafts. As the smoke consumers on some of these were for purposes requiring an intense dead heat, they burned pure anthracite, or even coke, and never smoked, except when a little bituminous coal got mixed with it by accident. The others, for purposes requiring not much heat, burned Merthyr, or free-burning Welsh coal, which, if stirred, gave off a little smoke. The smoke-consumers could not be substituted to do the work of either of these, as they gave a great, quick heat, which, as he had stated, was not applicable to the particular work. At Belmont Works they had nothing but smoke-consumers, and very rarely made any smoke; never, indeed, except when burning waste cotton or wood, which required stirring up in the coals to make them burn; or, as was stated in his letter, when, from any cause, the work employing steam had been stopped, the fires had to be made up on its being

Mr. VARLEY Suggested that it was desirable that any gentlemen present who had constructed smoke-consuming machines, should explain their principle to the meeting in a practical manner.

Professor BRANDE said, that in his opinion we were deeply indebted to Lord Palmerston, for having successfully undertaken the mitigation of the smoke nuisance in London, and to Messrs. Truman, Hanbury, and Co., who had taken such decided steps for practically carrying out the subject in their large establishment. We had often heard it stated, apparently upon high authority, that the business of a brewery could not be carried on without the production of a large quantity of smoke; and that, although it might be possible to apply smoke-preventers to the engine-furnaces, they never could be brought effectually to bear upon the brewing-coppers. Mr. Fraser, in the very clear statement with which he had favoured

the Society, had shown that this was a mistake; and with nineteen shillings per ton for our usual engine coals, and due care and trouble the gigantic issues of black smoke only ten shillings per ton for the screenings; but it is from breweries, with which we were but too familiar, most important that the small coal should be of good might not only be greatly diminished, but almost entirely quality, for we have frequently been supplied with a very got rid of; and, what was the most important of mischievous article under that name, being apparently the all, that this might be effected at a very consider- refuse and sweepings of the barges, or of the coal yards, able saving in the article of coals-a saving so large and consisting of anything but good coal; this, of course, as to cover the cost of the very expensive machinery not only does not burn as it should, but clogs the bars constituting the smoke-consuming apparatus which they with dirt, or clinkers, or in other ways seriously interferes had adopted. Dr. Brande then said, that the office with the smooth and satisfactory working of Jucke's which he held in the Mint had enabled him to acquire machinery. Dr. Brande expressed a hope that Lord Palconsiderable information and experience upon the sub-merston's act would be productive, not only of diminution ject, and that for the last eight or ten years a variety of of smoke, but of various and great improvements in the schemes for the prevention of smoke had been more or construction of furnaces and the economy of fuel; and less successfully adopted in that establishment, not so that its regulations would more especially put an end to much on account of the neighbourhood, which abounded the grievous smoke nuisances of the steamers on the river, in smoke-generating factories of one kind or other, but with which were equally annoying to the passengers, to the a view to decrease the annoyances to those who resided inhabitants of the banks, and to those passing the bridges. in the building. He was glad that the subject would It was much to be regretted, that the act did not extend now be forced upon all smoke-producers, and was certain to the still greater nuisance of the steamers below bridge. that the various inventions already extant for diminishing Mr. SIEMENS had understood Mr. Tomlinson to say or preventing smoke, would consequently be improved and that, although we might succeed in allaying the emission perfected, and that many new ones would gradually be of visible smoke from chimneys, we should still have to brought forward, not applicable to very large establish- suffer from the pernicious influence of the legitimate proments only, but to the minor nuisances of kitchen chim- ducts of combustion, namely, carbonic acid, aqueous nies, and of the smoke arising from dwelling-houses vapour, and nitrogen gas. He did not apprehend any generally-though to effect this end, a quantity of pre- inconvenience from the emission of those gases. The judice and obstinacy had to be encountered, which at carbonic acid gas was a very necessary constituent of our present seemed almost insurmountable. Mr. Brande said atmosphere, upon which the entire vegetable kingdom that, in discussing the smoke question, it was not neces- depended for its growth. The aqueous vapour returned sary to go into the theory of combustion, or to define to the earth in the form of rain, and the nitrogen, which what smoke is or is not. The dense black clouds of constituted the greater part of our atmosphere, passed carbonaceous matter, in a state of extreme division, through the furnace without undergoing any change. It, constituted the nuisance to be got rid of, and he therefore, appeared to him (Mr. Siemens), that the prewho could effect this in the most ready manner, vention of visible smoke was important in a sanitary point to the greatest extent, and upon the most reasonable of view, and he had no doubt that it was equally so terms, would be the most successful inventor. As far as considered commercially. He considered, however, that the present discussion was concerned, Dr. Brande said before entering into the examination of any of the that he should limit himself to Jucke's furnace, as that specific plans which had been brought forward in late was the only one which had been described to the meet-years (and their name was legion), the meeting should ing, and that in regard to it he should have but little to determine on the essential conditions on which perfect say, inasmuch as his experience and opinion entirely coin- combustion depended. Those conditions were, in his cided with that of Mr. Fraser. Several obstacles had, in opinion, firstly, The greatest attainable intensity of the first instance, occurred at the Mint, in regard to the combustion; and, secondly, The supply of sufficient successful working of the revolving chain of bars, and air to the fuel in its state of greatest incandescence to also in respect to the feeding of the fire, the bridge, the perfect the combustion. In support of the first probrickwork, and so forth; but these difficulties had been position he might mention the able experiments of gradually got over, and after using two of these furnaces Mr. D. K. Clark, on the furnaces of locomotive engines, successfully for five years, Dr. Brande obtained permission which went to prove that the economic evaporation of of the Master of the Mint to apply the invention to two a boiler was increased inversely in the square ratio as the twenty-horse power engine boilers, which had lately been grate surface was diminished. More recent analyses of done; in these new machines, the faults of those origi- the products of combustion contained in the smoke boxes nally constructed had been amended; and they appeared of locomotive engines, by the French philosopher, M. to act very satisfactorily. These four furnaces are con- Ebelman, proved that combustion was almost perfect nected with one shaft about 100 feet high, and, except in a passenger-engine with a thirty-inch fire. In goodswhen the fires are lighting, no visible smoke escapes. engines, with forty inches thickness of fire, and less But the greatest smoke nuisance in the Mint arose from draught, he found a small per centage only of carbonic the annealing furnaces, which are twelve in number; they oxide. The supply of a sufficient quantity of air to the are somewhat of the nature of a reverberatory furnace, furnace might be effected in two ways, namely, either by and at times a high and continuous red heat is required regulating the depth of fuel on the bars in proportion to to be kept up in them for several hours. Jucke's the available draught, or by admitting air, behind the fire smoke consumers have been applied to two of these, bridge, to the products of imperfect combustion. He and with perfect success, although, at the outset, deprecated the latter mode of proceeding, because the many difficulties presented themselves, more especially temperature of the fire was already considerably reduced as regarded the destruction of the brickwork and behind the bridge; but, supposing even it were not, it of the bridge; but by the adoption of a water-pipe at was a well-known fact that combustion ceased altogether the bridge, and the careful construction of every part of in an atmosphere which was already highly charged with the machine and furnace, these difficulties have been suc- carbonic acid. This observation did not apply forcibly to cessfully encountered, and the two furnaces produce Mr. Stevens's furnace, in which the air was admitted scarcely any smoke. As regards the economy of these fur- before the bridge, and in a highly heated state. naces, Dr. Brande's experience again coincided with that The conditions of obtaining perfect combustion, under of Mr. Fraser: the saving in the quantity of coal appears variable conditions of draught, were, he thought, complied unimportant, though certainly in favour of Jucke's con- with in the furnaces of Jucke and Hazeldine, which he sumers; but as respects quality, the smoke-consumers considered were ingenious adaptations of Mr. Bodmer's being exclusively fed with screenings, or small coal, the furnace with travelling bars. The expense and liability saving is very considerable; at one period we were paying to derangement were, however, serious objections.

He had had occasion to apply Mr. Hunt's furnace, consisting of slanting bars, upon which the fuel fell from a hopper by its natural gravity. At the first, the combustion was imperfect, but by providing a means of altering the inclination of the bars, and thereby the thickness of fuel to the conditions of draught, he had obtained a very perfect result. This furnace required, certainly, occasional attention to prevent the fuel from clogging in the bottom of the hopper; but this objection, he considered, was amply outweighed by its comparative simplicity.

Mr. ROBT. ROUGHTON said that the length of the furnaces was generally greater than could be managed with ease, and that it was extremely difficult to keep a furnace of a length of eight or ten feet covered with a thin layer of coals. In marine furnaces the engines were made smaller, and they were much more manageable on that account. He feared that Mr. Jucke's contrivance would not work well if subjected to a very great draught of air.

Mr. Lowe remarked that gas companies were less sinners, in respect of emitting smoke from their works, than, perhaps, any other traders in the kingdom; and when he assured the meeting that it was a fine to use one ounce of Newcastle coals in their furnaces, he thought they would agree that not much smoke could be seen from their chimnies. They only used coke. He would just say as an encouragement to those present, that the prevention of smoke was no such difficult matter after all. All that was required was a knowledge of combustion. In the premises of his father, at Derby, who was, 30 years ago, one of the most extensive malsters in Great Britain, 200 quarters of malt were dried with the aid of two furnaces supplied with bituminous coal, without a chimney, and without a particle of smoke. The supervisors and excisemen could not understand it, and persons went down from the Board of Excise to inspect the malting-house, but they could not imagine how the heat could be passed through the malt without a chimney; and yet the men employed by his father were men earning 12s. or 15s. per week wages. The way in which it was effected was by passing a current of air from the front over the whole, and adjusting the fuel in front, as it was now done in the furnaces at the Mint. He had often occasion to cross in the steamer from Holyhead to Kingstown, and he had remarked the splendid bow of carbon which the "Columbia" left in her wake from port to port. He had pointed it out one day to the captain of the vessel, and he had been permitted to try the experiment of stoking three of the furnaces every ten minutes instead of every twenty minutes; and by leaving the furnace door on the latch, instead of closed tight; the result was that the smoke all disappeared; and from that day to this the engines of the "Columbia" were enabled to make twenty-one revolutions per minute instead of nineteen; and no black smoke was ever seen from her funnel, to pave the sky with carbon from port to port.

1

Mr. FRASER, after thanking the meeting for their approval of his remarks, expressed regret at the form which the discussion had assumed. He had confined himself to the details of one successful plan, in the hope that others, including Messrs. Stevens, Hall, and Hazeldine, would have detailed the plan adopted in their furnaces. Mr. Fraser then explained the working models of Hall and Hazeldine-which were exhibited--both of which he had seen in successful operation at Messrs. Price and Co.'s works on the preceding day, and both of which made a fire and consumed its smoke in a way which left nothing to be desired. Hall's consisted of a series of bars, cast the whole length of the fire, which were moved alternately by an eccentric shaft in front; the movement was very slow, but the effect was to supply the fire with fuel from a stopper in front, as in Jucke's. Hazeldine's patent accomplished the same results by a different arrangement of bars, which were cast the width of the fire, transversely with the boiler. A peculiar motion was given by a cam to each of the bars, the object being to supply the fire, as in the other

places mentioned, from a stopper in front of the furnace door being opened vertically by a rack and pinion. In conclusion, Mr. Fraser remarked that the foregoing plans would be effectual in a very large portion of the furnaces at present in operation, which would come under the regula tions of the New Act. He had no doubt difficulties would arise in the application to chemical works, and dyers' pans, to which it was not practicable to apply these machines. He thought steam might be advantageously applied, or, where a high temperature was required, a modification of Neilson's hot blast might be adopted; but here, of course, he did not speak from experience.

The CHAIRMAN then thanked Mr. Fraser, in the name of the Society, for the excellent, interesting, and suggestive paper he had just read, and expressed a hope that the number of inventions now before the public would shortly cause an almost universal abatement of the smoke nuisance.

The Secretary announced that at the meeting of Wednesday next, the 7th of December, a paper would be read "On Miners' Safety Lamps," by Dr. Glover.

ON RECENT IMPROVEMENTS IN CHRONOMETERS. (a)

BY E. T. LOSEBY.

In the first portion of the paper which I had the honour of reading before the Society last session, the train and escapement of chronometers were particularly alluded to, and the following conclusions were drawn from the argu

ments adduced :

"

once winding up, are inferior in principle to those which That timekeepers which go for long intervals with go for short ones, and that, consequently, chronometers which only go two days, besides being less expensive, are better than those which go eight days, as any irregularity in the wheel-work or main-spring adjusting, would more frequently correct itself;

not contribute much to accuracy of going, and that the That perfection of form in the train-wheel teeth does hardness of the wheels and pinions, the suitability of the materials, &c., and the smoothness of the acting surfaces, will enter quite as largely into the question of durability as perfection of form in the teeth; and

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That the chronometer escapement has not been improved since it left the hands of Arnold and Earnshaw, in the last century, and that experience does not point to the escapement as the source of any remaining error." It is not now intended to introduce the subject of watchmaking generally, but manufacturers would do well to make themselves better acquainted with the improvements which have been made in the higher branches of horology, in order to apply them to the cheaper kind of watches so far as expense will allow; for, taken altogether, there are probably few arts in which the manufacturers and workmen possess so little knowledge of what really contributes to excellence as do the generality of persons engaged in watch and clock making: their attention having been directed more to mechanical workmanship and cheapness of production, than to the theory and principles upon which the various contrivances are based. Had would not have remained comparatively unemployed in greater intelligence prevailed, the compensation-balance lever watches, nor should we have had such instances as the substitution of gold balances for steel ones-gold, as a material, being in every way inferior to steel, from its expanding more with heat, and being more easily bent or scratched. The great liability to error which the compensation-balance prevents, should cause it to be univer

(a) A Paper on this subject was read at the Twenty-second Ordinary Meeting of the Society, Ninety-ninth Session, May 25th, 1853, and an abstract was published in this Journal at the time, vol. 1, p. 313.

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