« ElőzőTovább »
which has been found to agree with the experience 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
ment was not made from any motives of economy 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 :
The total cost of the fourteen furnaces, including brickwork, has been about 3,000l. The consumption of coals in the establishment is about 6,000 tons per annum. The saving in the coal account, since the introduction of the patent furnaces to July 1st of the present year, has been as follows:– July 1, 1848, £69 40 ,, 1849, 631 4 0 ,, 1850, 1606 0 0 ,, 1851, 1925 12 0 ,, 1852, 1906 0 0 ,, 1853, 2200 00
4,8338 0 0
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 losin 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 sumaces, 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 of a tylindrical form, with spherical ends (without tubes; its length is 20 feet; diameter 4 feet; and when * With the common surnace, the rate of evaporation **, Tolbs of water by the consumption of' lib. of Øds Redhugh coals. We began to make experiments **ain the exact degree of saving effected by the Palent surnace on the 12th of September, and continued on throughout the week, the engine working 62 hours.
sing this time we evaporated 47,5201bs. of water by the consumption of 5,4881bs. of ord's Redhugh coals; ** of which was ims. 6d. at the furnace mouth. The **ing power in this case is equal to 8.65 lbs. of * with lb. of coal, being a saving in fuel of nearly is percent.”
"will be noticed in the Table of Furnaces erected at **tevery, that a considerable reduction has been made in the area of all the new furnaces, varying from 20 to 30 ** with an increase of water or wort evaporated of lāpercent. in one of the large brewing coppers. This *om the fire-door not requiring to be opened, and on the movement of the bars which prevents any scoriae og up the air spaces of the fire. “It will be evident *his plan, which has been successful on land, would **one modification to make it equally so on the Water. M. Tailfer, of Paris, in 1845, gave his attention * * *hject, and the French government placed a *...* at his disposal for the experiment.
It would appear at first sight that the wear and tear of a *hine apparently so complicated, must exceed the *Ponso of the common fixed bars. This, however, has **n found to be the case, and it need not be so if ordinary ote is given to the machine, and a periodical ex*tion is made,such as any other machine of equal ** Poducing equally important results would re*ive. Within the last . a set of bars have been rei. for the first time, which have been in use since May, *; and three fourths of the old bars are being again
** another furnace, where the boiler is of its im: r: * the one from which they have been re..[a
**llion, it must not be understood that the writer * this the only plan for the combustion or pre
W*ing the four and a half years, about 18 tons of fixed lea would have been used, which at £8 or £9 per ton, would ***iderable margin for repairs. It should be stated, at *time, that there are facilities for repairs at Messrs. on o which many others have not, workmen being always * ready to execute them.
vention of smoke, for he has reason to believe that the eminent firm of Messrs. Price and Co. have been equally successful with other plans as well as with the one to which he has drawn attention; but he has confined his remarks to his own immediate practice, leaving inventors and others to give the result of their own experience.
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 ...i by legislative enactments. But not only was the inventor to be thanked, but thanks were also due to Messrs. Truman, Hanbury, 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, for 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 8.6lb. of water to Ilb. of coals. ...This was the only good test for ascer. taining 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 moyeable 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 orchimney, 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 cindels, 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 resent 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. Mr. G. F. Wilson said, that as Mr. Fraser had referred to a visit that he paid yesterday to the works of Price's Patent Candle Company, where he saw a large number of smoke-consumers in successful operation, he, as a Director of these works, might perhaps be allowed to say a few words on the subject. A fortnight back, on being applied to by the Secretary to the Society of Arts, he had noted down some of the results of their experience of three different smoke consumers. When the letter was printed in the Society's Journal, their people at Vauxhall said it was correct except as to the number of smoke-consumers, which was twenty-one instead of nineteen. The letter should have expressed that all these smoke-consumers were under steam boilers. They had one sort of smokeconsumer or other under many kinds of boilers, marine, waggon, Cornish, and cylindrical, with two tubes and the fire underneath, but still they were under steam boilers only. Of brewers' coppers he knew very little, and had never seen the bottom of one; but, from what he heard the other day, in conversation with one of the largest brewers, he should suppose that they had difficulties to contend with that we knew nothing of, especially in the necessarily great size of their furnaces. It had been said that the chimnies at Price's Works sometimes smoked. They certainly did a little, and for a short time, but the fault did not rest with the smoke-consumers. At the Battersea Works 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 u 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
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 ". 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 same 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 admirably, and never got out of order. In some cases want of i. and in all cases want of business experience and judgment in the inventors, had, he thought, been the principal cause of the slow progress of smoke consumers; but there was another cause at work. The manufacturers who put up the first of the patent furnaces had a direct interest in holding their tongues, or, what they called in Scotland “keeping a calm sough.” The London small coals were at this time sold at about 4s. a ton cheaper than they would have been had furnaces well adapted for burning them been more generally used; at Vauxhall especially, acting for many others as well as themselves, they had no right to make a stir, or to do more than give such reports of the furnaces as the inventors had a claim to ask for. This year, however, circumstances had changed; on account of some small coalconsuming furnaces being at work, and from other causes, London small coals had risen to even above their real value. It seemed, therefore, that we must look in future to the north for our supply, and that the coming into general use of the smoke-consuining small-coal burning furnaces, as they would cause a larger demand, would make the supply more steady, and reduce rather than raise the price of small coal. He need not say what pleasure it gave him to have a hit, however humbie a one, at what was in some towns at least an utterly intolerable nuisance. 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 carryin out the subject in their large establishment. We 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 due care and trouble the gigantic issues of black smoke from breweries, with which we were but too familiar, might not only be greatly diminished, but almost entirely got rid of; and, what was the most important of all, that this might be effected at a very considerable saving in the article of coals—a saving so large as to cover the cost of the very expensive machinery constituting the smoke-consuming apparatus which they had adopted. Dr. Brande then said, that the office which he held in the Mint had enabled him to acquire considerable information and experience upon the subject, and that for the last eight or ten years a variety of schemes for the prevention of smoke had been more or less successfully adopted in that establishment, not so much on account of the neighbourhood, which abounded insmoke-generating factories of one kind or other, but with a view to decrease the annoyances to those who resided in the building. He was glad that the subject would now be forced upon all smoke-producers, and was certain that the various inventions already extant for diminishing or preventing smoke, would consequently be improved and p. and that many new ones would gradually be
ught forward, not applicable to very large establishments only, but to the minor nuisances of kitchen chimnies, and of the smoke arising from dwelling-houses generally—though to effect this end, a quantity of prejudice and obstinacy had to be encountered, which at Present seemed almost insurmountable. Mr. Brande said that, in discussing the smoke question, it was not necessay to go into the theory of combustion, or to define what smoke is or is not. The dense black clouds of carbonaceous matter, in a state of extreme division, constituted the nuisance to be got rid of, and he who could effect this in the most ready manner, to the greatest extent, and upon the most reasonable terms, would be the most successful inventor. As far as the present discussion was concerned, Dr. Brande said that he should limit himself to Jucke's furnace, as that was the only one which had been described to the meeting, and that in regard to it he should have but little to *W, inasmuch as his experience and opinion entirely coinoiled with that of Mr. Fraser. Several obstacles had, in the first instance, occurred at the Mint, in regard to the occessful working of the revolving chain of bars, and *in respect to the feeding of the fire, the bridge, the brickwork, and so forth; but these difficulties had been gradually got over, and after using two of these furnaces "lossfully for five years, Dr. Brande obtained permission of the Mäster of the Mint to apply the invention to two wenty-horse power engine boilers, which had lately been *; in these new machines, the faults of those originally constructed had been amended; and they appeared * Art very satisfactorily. These four furnaces are connected with one shaft about 100 feet high, and, except When the fires are lighting, no visible smoke escapes. But the greatest smoke nuisance in the Mint arose from the annealing furnaces, which are twelve in number; they **omewhat of the nature of a reverberatory furnace, *nd at times a high and continuous red heat is required to be kept up in them for several hours. Jucke's "noke consumers have been applied to two of these, and with perfect success, although, at the outset, many difficulties presented themselves, more especially * Tegarded the destruction of the brickwork and of the bridge; but by the adoption of a water-pipe at the bridge, and the careful construction of every part of the machine and furnace, these difficulties have been successfully encountered, and the two furnaces produce **ely any smoke. As regards the economy of these fur* Dr. Brande's experience again coincided with that of Mr. Fraser: the saving in the quantity of coal appears "nimportant, though certainly in favour of Jucke's con*; but as respects quality, the smoke-consumers
ing exclusively fed with screenings, or small coal, the *ing is very considerable; at one period we were paying
nineteen shillings per ton for our usual engine coals, and only ten shillings per ton for the screenings; but it is most important that the small coal should be of good quality, for we have frequently been supplied with a very mischievous article under that name, being apparently thc refuse and sweepings of the barges, or of the coal yards, and consisting of anything but good coal; this, of course, not only does not burn as it should, but clogs the bars with dirt, or clinkers, or in other ways seriously interferes with the smooth and satisfactory working of Jucke's machinery. Dr. Brande expressed a hope that Lord Palmerston's act would be productive, not only of diminution of smoke, but of various and great improvements in the construction of furnaces and the economy of fuel; and that its regulations would more especially put an end to the grievous smoke nuisances of the steamers on the river, which were equally annoying to the passengers, to the inhabitants of the banks, and to those passing the bridges. It was much to be regretted, that the act did not extend to the still greater nuisance of the steamers below bridge.
Mr. SIEMENs had understood Mr. Tomlinson to say that, although we might succeed in allaying the emission of visible smoke from chimneys, we should still have to suffer from the pernicious influence of the legitimate products of combustion, namely, carbonic acid, aqueous vapour, and nitrogen gas. He did not apprehend any inconvenience from the emission of those gases. The carbonic acid gas was a very necessary constituent of our atmosphere, upon which the entire vegetable kingdom depended for its growth. The aqueous vapour returned to the earth in the form of rain, and the nitrogen, which constituted the greater part of our atmosphere, passed through the furnace without undergoing any change. It, therefore, appeared to him (Mr. Siemens), that the prevention of visible smoke was important in a sanitary point of view, and he had no doubt that it was equally so considered commercially. He considered, however, that before entering into the examination of any of the specific plans which had been brought forward in late years (and their name was legion), the meeting should determine on the essential conditions, on which perfect combustion depended. Those conditions were, in his opinion, firstly, The greatest, attainable intensity of combustion; and, secondly, . The supply of sufficient air to the fuel in its state of greatest incandescence to perfect the combustion. In support of the first proposition he might mention the able experiments of Mr. D. K. Clark, on the furnaces of locomotive engines, which went to prove that the economic evaporation of a boiler was increased inversely in the square ratio as the grate surface was diminished. More recent analyses of the products of combustion contained in the smoke boxes of locomotive engines, by the French philosopher, M. Ebelman, proved that combustion was almost perfect in a passenger-engine with a thirty-inch fire. In goodsengines, with forty inches thickness of fire, and less draught, he found a small per centage only of carbonic oxide. The supply of a sufficient quantity of air to the furnace might be effected in two ways, namely, either by regulating the depth of fuel on the bars in proportion to the available draught, or by admitting air, behind the fire bridge, to the products of imperfect combustion. He deprecated the latter mode of proceeding, because the temperature of the fire was already considerably reduced behind the bridge ; but, supposing even it were not, it was a well-known fact that combustion ceased altogether in an atmosphere which was already highly charged with carbonic acid. This observation did not apply forcibly to Mr. Stevens's furnace, in which the air was admitted before the bridge, and in a highly heated state. The conditions of obtaining perfect combustion, under variable conditions of draught, were, he thought, complied with in the furnaces of Jucke and Hazeldine, which he considered were ingenious adaptations of Mr. Bodmer's furnace with travelling bars. The expense and liability 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 yo not work well if subjected to a very great draught of alt. Mr. Lowe remarked that gas companies were less sinners, in respect of emitting smoke from their works, than, |. 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 oftwo furnacessu plied with bituminous coal, without a chimney, and withbut 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. t Mr. FRAson, 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. i`raser 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 sjow, but the effect was to supply the fire with fuel from a stopper infront, as in Jucke's. Hazeldine's patent accom; lished the same results by a different arrangement of ars, 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, asin 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 regulations 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 arguments adduced — “That timekeepers which go for long intervals with once winding up, are inferior in principle to those which 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; “That perfection of form in the train-wheel teeth does not contribute much to accuracy of going, and that the 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 * 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 hav. ing been directed more to mechanical workmanship and cheapness of production, than to the theory and principles upon which the various contrivances are based. Had greater intelligence prevailed, the compensation-balance would not have remained comparatively unemployed in 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. *. 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.