FENTON'S PATENT IMPROVEMENTS IN SAFETY-VALVES. (Patent dated May 1, 1854.) WE have much pleasure in bringing, this week, before our readers, an invention of unusual merit,-one which, if brought into general use, is calculated we believe to put an end to boiler explosions for the future, so far, at least, as a safety-valve, perfect in its action, can conduce to such a result. The public is indebted for the improvement to Mr. J. Fenton, of Low Moor. As it is quite unnecessary for us to write one word to engineers and others concerning the utility of a safety-valve which cannot possibly be obstructed in its action, either accidentally or designedly, we shall proceed at once to describe the nature of his arrangement. Mr. Fenton's invention consists of two parts:-First. In forming and fitting a single valve in an improved manner; and, Second. In combining two of the improved valves together in a certain manner, to be described hereafter. It is to the latter of these that our preceding remarks chiefly apply. It will be necessary, however, to present the two in their proper order. The first part comprises the following arrangements:-The valve itself, which is of the form of a sphere, rests upon a spherical seat, and is provided with cup and ball fittings to the lever and appendages. A cup rests immediately over the sphere in connection with a lever, in which it is held by a spindle. One end of the lever is held upon a vertical spindle. The nut by which it is secured is spherical at its lower end, and fits into a cofresponding cup on the upper side of the lever. The long arm of the lever is provided with a like fitting, by which it is connected to the spindle of a spring balance, while the lower end of the spring balance spindle is connected by a similar fitting to a rod or arm projecting from the boiler. The object of these fittings is to allow of play at every joint. And in order further to prevent any part of this valve from sticking, care is taken that the parts which come in contact in forming the joints shall not be of the saine metal. In the engravings in the preceding page is shown the manner in which the improved single safety valve is constructed, and also modifications of it adapted to locomotive and marine steam boilers. Fig. 1 is an elevation, with the valve seat in section, of a locomotivē safety-valve; fig. 2 a plan; and fig. 3 a cross section. A A is a portion of the boiler plate. BB is the valve seat casing, which is cast in brass or gun metal, and bolted to the boiler by the flange, CC. cc is the valve seat, which is formed out of a circular edge, turned and ground to fit accurately the valve, D. The upper part of the valve seat is dished out in the manner represented by the dotted lines in fig. 1, in order that directly the valve is lifted from its seat by the pressure of the steam, there may be sufficient space for the steam 18 blow off freely. C'C' are four guides to insure the valve falling accurately into its seat. The valve, D, is cast hollow, as indicated in fig. 3, and afterwards turned perfectly spherical, or as nearly so as possible. E is a cup or cap cast concave, and ground të fit the upper part of the valve, D. F is a projection or spindle cast in a piece with the cup, and formed with a semicircular end, which fits into a corresponding semicircular cup in the under side of the lever, G. H is a vertical spindle, the lower end of which is screwed into a snug, H', cast upon the valve seat casing. The upper part of this spindle is also cut with a screw thread, upon which is fitted the nut, I, the underside of which is made spherical, and fits into a corresponding cup formed in the upper part of the lever, G; a conical hole being drilled through the lever at this part, so as to enable it to be passed over the end of the vertical spindle, and retained there by the nut, I, which thereby acts as a fulcrum to the lever. The opposite end of the lever is furnished with a similar nut and hole, J, through which the screwed end of the spindle, K, of an ordinary spring balance, Li is passed, the lower end of the box of the balance being fitted with a screwed spindle, M, which is passed through the rod or arm, N, and fitted with a nut, O. The lever, Gis curved down at each end, as shown in fig. 1, in order to bring the centres of the spherical nuts in the same line with the central line of the lever, and thereby to render the action of the valve more accurate and certain. We are now in a position to describe the second and most important part of the invention. This consists in combining two of the valves just described in such manner that when any action takes place, either intentionally or otherwise, the tendency of which is to overweight the valve, one of the two immediately becomes a fulcrum, about which the other is raised, The value of this simple but perfectly efficient arrangement cannot be estimated too highly. Figs. 4 and 5 represent the two valves, each constructed in precisely the same manner as the foregoing. P is a volute spring placed between the nut, I, and the end of the lever, ON PRODUCTS OBTAINED FROM COAL. 531 G, which acts either as a fulcrum or as a weight to the lever, according to the adjustment of the spring balance; for should the spring balance be screwed down or weighted to resist a greater pressure than the volute spring, then the volute would become compressed when the steam blew off through the valves; but should the volute be screwed down to an excess of pressure over the spring balance, then the volute would act as a fulcrum to the lever, and the spring balance would become lifted. We sincerely trust that this arrangement will soon become so generally adopted, as to put an end to the disasters arising from boiler explosions, which are found to produce on an average, at least one death daily in this country alone. The inventor also employs a safety-valve adapted for either stationary or marine boilers, in which he employs a pair of volute springs acting directly upon the top of the valve, and thereby dispenses with the lever and spring balance. ON PRODUCTS OBTAINED FROM COAL. THE accompanying table will give an idea of the numerous products which chemists had ascertained to exist in the substances distilled from coal; It will be perceived from this Table that the products obtained from coals were divisible into three classes, namely, gases, liquids, and solids. He did not intend to dwell upon the first class, the gases, which subject was SO extensive that it would require to be treated in a separate paper. With respect to the solid products of coal, he would first allude to the coke which was obtained in making gas. The coke generally obtained from gas works was very inferior. Great efforts had lately been made to obtain the various products of coal, and also to manufacture good coke for cupola and railway purposes, at the works of the London Gas Company; but he was not aware of the exact results obtained. The liquid products from coal could be divided into two distinct classes, the aqueous portion and the tarry portion. The aqueous portion was valuable chiefly for the ammonia which it contained, and which was put to the following amongst other uses: In the first place, it was bought by chemical The above highly-interesting and important remarks form part of a lecture read by Professor Calvert before the Society of Arts, &c., on the evening of Wednesday, Nov. 22. manufacturers, who obtained from it sulphate of ammonia for agricultural purposes, sal ammonia for soldering, and which was also used in calico and print works, in the production of a style of prints called "steam goods." From these two salts was obtained hartshorn, which was extensively employed in pharmacy. Ordinary coal gas liquor was often employed to obtain, by distillation, common ammonia, which was much used in dye works; also to produce, with lichens, beautiful colouring matters, called orchil and cudbear, valuable for the production on silk and wool of delicate purple hues. The production of this colour and the influence of ammonia was exceedingly interesting, on the ground that the colouring principle called orcine was colourless until acted upon by the oxygen of the air and ammonia. If to this ammonia a fixed alkali be added, then no more orchil or cudbear was produced; but litmus, which was now much used in chemistry as a test for acids and alkalis. One of the most interesting and useful of the applications of ammoniacal liquors was in the preparation of ammoniacal alum. The manufacture of this substance had become very extensive of late years. At the chemical works of Messrs. Spence and Dixon, near Manchester, 800,000 gallons of ammoniacal liquor were annually consumed in the manufacture of ammoniacal alum, the ammoniacal liquor being obtained from the extensive gas works belonging to the corporation of Manchester. The manufacture of this substance, which was so valuable as an astringent, and also to the dyer and calico printer, furnished such a remarkable illustration of the value of chemistry in aiding manufacturers and commerce, that he would explain briefly the method of producing it. To obtain this substance called ammoniacal alum, a refuse product of coal pits, known as aluminous shale, was heaped into small mounds and slowly burned. Shale was ge 532 ON PRODUCTS OBTAINED FROM COAL. nerally found in hard masses, which fell from the roofs of the coal mines, and the object of burning it was to render it porous and friable. The calcined friable mass was then placed in large leaden vessels, with sulphuric acid, having a specific gravity of 1-65, being the strength in which it was obtained from the leaden chambers. It was a curious fact that this sulphuric acid could be produced from another refuse found in coal mines, namely, pyrites. The calcined shale and sulphuric acid were heated in these leaden chambers for about forty-eight hours; the liquor was then drawn off and put into another vessel, into which the ammonia generated from another refuse of coal, namely, the gas liquor, was introduced in a gaseous state. Thus these three substances, the alumina from the shale, the sulphuric acid obtained from the pyrites, and the ammonia from the gas liquor, combined to produce ammoniacal alum, which then only required purifying by successive processes of crystallization to give it that remarkable purity in which it was furnished to the commercial world by Messrs. Spence and Dixon, and other manufacturers. In so A great boon would be conferred upon agriculturists if the ammonia which was produced when coke was made in common ovens, were saved, as recommended by Dr. Lyon Playfair, who estimated that every hundred tons of coal would yield, on the average, about six tons of sulphate of ammonia. The quantity of coke made annually in England amounted to at least 1,000,000 tons, yielding, therefore, 60,000 tons of sulphate of ammonia, which might be made a cheap and valuable agent in agriculture. When the minimum advantages which manufacturers had derived from saving the ammoniacal products in gas works were remembered, it ought to encourage coke manufacturers and engineers to exert themselves to effect the same. doing they would confer a great benefit on the public, as coke would thus be enabled to be sold at a lower price. It was interesting to reflect that, no doubt, at the present day, tons of salts of ammonia were made, where formerly pounds were imported into England, from a district called Ammonia, in Nubia, in Egypt, and which, in the form of sal-ammonia, was derived from heating in glass vessels the soot which had been produced by the burning of camels' dung. The same line of thought might also be applied to alum, which formerly came entirely from the East, then from the environs of Rome, and now, through the application of chemistry to manufactures, the progress of human intelligence, the undaunted perseverance of our countrymen, was manufactured in England from what had been hitherto noxious and refuse products. Mr. Crace Calvert next spoke of tar. This substance was generally sold to the tar distillers, who obtained from it a volatile fluid called coal naphtha, a light oil, composed principally of carbolic acid, and a heavy oil of tar, a solid substance called pitch being also left in the retort. Mr. Crace Calvert then proceeded to state the applications which these various materials received. Pitch had of late years been used successfully by the corporation of Manchester in assisting to pave the streets. When the streets were repaved, a large quantity of this pitch, to which was added tar and asphalte, was heated in portable boilers in the street, and was poured, when in a hot liquid state, upon small pebbles or gravel between the interstices of the paving stones, which were thus firmly bound together, and became so durable that the most frequented thoroughfares in Manchester, when thus paved, had not required repaving for several years. There was, however, this important sanitary advantage connected with the plan, and to which he wished to draw special attention; namely, that no impure matter and stagnant water could percolate through the impervious pavement, and collect beneath, giving forth noxious effluvia, to the injury of the health of the inhabitants of large cities, and even causing dangerous epidemics. The importance of this process would be the more apparent when it was calculated what a vast surface area was presented by the streets of a large city. This pitch had also of late been submitted by Mr. Bethell to a further distillation in retorts, which enabled him to obtain a porous, but at the same time a dense coke; and the oils which were distilied in this operation appeared to be such as might be employed to advantage as lubricating agents for common and heavy machinery. Before passing to the various volatile products obtained from the distillation of tar, Mr. Crace Calvert stated, that tar had been applied lately, when mixed with gutta percha or India-rubber, to insulate telegraph wires, and to prevent metals from being acted upon by the atmosphere. One of the first products which came over in the distillation of tar, was a mixture of very volatile hydro-carbons, which had received the name of crude naphtha; and this, when again distilled, was sold under the name of naphtha, and was chiefly burned by the keepers of stalls in streets and markets. When naphtha had been mixed with turpen. tine, it was called camphine, and was burned in lamps in private dwellings. When it was intended to apply this naph ON THE MEANS OF AVOIDING SMOKE IN BOILER FURNACES. tha to more particular purposes, it was purified by mixing it with ten per cent. of its bulk of concentrated sulphuric acid; and when the mixture was cold, about five per cent. of peroxide of manganese was added, and the upper portion was submitted to distillation. The rectified naphtha found in the receiver had a specifie gravity of 0·85. This rectified naphtha was used to dissolve caoutchouc for making garments impermeable to water, known as Mackintoshes; and when sulphur was added, and the mixture submitted to steam having a temperature of from 400° to 500°, vulcanized India-rubber was produced. Rectified naphtha was also used for mixing with wood naphtha, to render the latter more capable of dissolving resins for the production of cheap varnishes. When this rectified naphtha had been submitted to a series of further purifications, it had received from an eminent French chemist, named Pelouze, the name of "benzine," which had the property of removing, with great facility, spots of grease, wax, tar, and resin, from fabrics and wearing apparel, without injuring the fabric, its colour, or leaving any permanent smell or mark, as was the case with turpentine. Benzine had, through his (Mr. Calvert's) exertions, been introduced into England, and had been found most valuable in brightening velvets, satins, &c. The numerous uses to which this valuable product could be applied in manufactures must, in time, render it of extensive employment in place of alcohol and other fluids, which were, generally speaking, too expensive for common commercial purposes. As an instance, he cited that at the present day, in Yorkshire, there was a large quantity of wool dyed before it was spun, principally for carpet manufactures. It was then necessary to oil this dyed slubbing wool, as it is called, and up to the preseut time no means had been discovered of removing the oil without injuring the colour, and thus this oil remaining in the fabric, materially injured the brilliancy of the colour, as well as rendered the carpets thus manufactured liable to become sooner faded or dirty. Now, by the employment of benzine, which had not the property of dissolving colours, the oil could be removed from such fabrics, and the full brilliancy of the colours fixed on this slubbing wool be restored. He also stated that this benzine could be employed with advantage in photography, in removing the grease from daguerreotype plates. When this benzine was treated with strong nitric acid, it gave rise to a substance called nitro-benzine, which was every day becoming more and more employed as a substitute for essence of bitter almonds, and used for flavouring 533 dishes, and communicating scents to perfumery, soaps, &c. It was interesting to observe that thus, by the triumphs of chemistry, a delicious perfume had been produced from the noxious smelling refuse of (To be continued.) coal. ON THE MEANS OF AVOIDING THE discussion on Mr. Woodcock's paper on the above subject being renewed at the Institution of Civil Engineers on the evening of Tuesday, November 21, it was shown that, although critically precise experiments for determining the amount of evaporation had not been previously made, there was no doubt of the fact of its being possible to use a lower-priced fuel, and to do the full amount of work with the boiler, without evolving any opaque smoke from the chimney; and thus, whilst complying with the requirements of the legislature, a pecuniary saving could be effected. Recently, however, by experiments on a cylindrical boiler 17 feet long by 3 feet diameter, it was said to have been shown, that 8 lbs. of water injected at 42° Fahr., was evaporated by 1 lb. of Newcastle small coal, when Mr. Woodcock's apparatus was in use. It was found that, with small bituminous coal, a better evaporation was main tained than when Llangennoch coal was used, and without any appearance of smoke. The cast-iron bridges of the furnace did not appear to suffer from the effects of the fire; the passage of the air keeping the metal comparatively cool. As soon as the valves of the apparatus at Messrs. Meux and Co's Brewery were closed, there was a dense smoke; but on the instant of opening them, the heated gases combined with the oxygen of the air, and flashed into bright flame. Llangennoch coals had been generally used at Messrs. Meux and Co.'s Brewery, not from any economy they offered, as they were not so strong as the Newcastle coals, but for the sake of the neighbourhood, as they did not give out opaque smoke; however, with the apparatus described by Mr. Woodcock, small Newcastle slack could be used, and as it could be purchased at 14s. per ton, whilst the Llangennoch coal cost 28s., there must, it was contended, be a money saving, and the boilers worked quite as efficiently. As to the general similitude between the principles advocated by Mr. C. Wye Williams, and those brought into notice by Mr. Woodcock, almost the only difference appeared to be, that the former insisted on the necessity for the coldness of the air admitted, whilst the latter contended for the advantage |