Chapter 134

STEREOTYPE PRINTING, signifies printing by fixed types, or by a cast typographic plate. This plate is made as follows:—The form, composed in ordinary types, and containing one, two, three, or more pages, inversely as the size of the book, being laid flat upon a slab, with the letters looking upwards, the faces of the types are brushed over with oil, or preferably, with plumbago (black lead). A heavy brass rectangular frame of three sides, with bevelled borders, adapted exactly to the size of the pages, is then laid down upon the chase,[61]to circumscribe three sides of its typography; but the fourth side, which is one end of the rectangle, is formed by placing near the types, and over the hollows of the chase, a single brass bar, having the same inwards sloping bevel as the other three sides. The complete frame resembles that of a picture, and serves to define the area and thickness of the cast, which is made by pouring the pap of Paris plaster into its interior space, up to a given line on its edges. The plaster mould, which soon sets, or becomes concrete, is lifted gently off the types, and immediately placed upright on its edge in one of the cells of a sheet-iron rack mounted within the cast-iron oven. An able workman will mould ten sheets octavo in a day, or 160 pages. The moulds are here exposed to air heated to fully 400° F., and become perfectly dry in the course of two hours. As they are now friable and porous, they require to be delicately handled. Each mould, containing generally two pages octavo, is laid, with the impression downwards, upon a flat cast-iron plate, called the floating-plate; this plate being itself laid on the bottom of the dipping-pan, which is a cast-iron square tray, with its upright edges sloping outwards. A cast-iron lid is applied to the dipping-pan, and secured in its place by a screw. The pan having been heated to 400° in a cell of the oven, under the mould-rack, previous to receiving the hot mould, is ready to be plunged into the bath of melted alloy contained in an iron pot placed over a furnace, and it is dipped with a slight deviation from the horizontal plane, in order to facilitate the escape of the air. As there is a minute space between the back or top surface ofthe mould and the lid of the dipping-pan, the liquid metal, on entering into the pan through the orifices in its corners, floats up the plaster along with the iron plate on which it had been laid, thence called the floating-plate, whereby it flows freely into every line of the mould, through notches cut in its edge, and forms a layer or lamina upon its face, of a thickness corresponding to the depth of the border. Only a thin metal film is left upon the back of the mould. The dipping-pan is suspended, plunged, and removed by means of a powerful crane, susceptible of vertical and horizontal motions in all directions. When lifted out of the bath, it is set in a water-cistern, upon bearers so placed as to allow its bottom only to touch the surface. Thus the metal first concretes below, while, by remaining fluid above, it continues to impart hydrostatic pressure during the shrinkage attendant upon refrigeration. As it thus progressively contracts in volume, more melted metal is fed into the corners of the pan by a ladle, in order to keep up the hydrostatic pressure upon the mould, and to secure a perfect impression, as well as a solid cast. Were the pan more slowly and equably cooled, by being left in the air, the thin film of metal upon the back of the inverted plaster cake would be apt to solidify first, and intercept the hydrostatic action indispensable to the purpose of filling all the lines in its face. A skilful workman makes five dips, containing two pages octavo each, in the course of an hour, or about nine and a half octavo sheets per day. The pan being taken asunder, the compound cake of mould and metal is removed, and beat upon its edges with a wooden mallet, to detach the superfluous metal. The stereotype plate is then handed over to the picker, who planes its edges truly square, turns its back flat upon a lathe to a determinate thickness, and carefully removes the little imperfections occasioned by dirt or air left among the letters when the mould was cast. Should any of them be damaged in the course of the operation, they must be cut out, and replaced by soldering in separate types of the same size and form.[61]Chase (chassis, frame, Fr.), quoin (coin, wedge, Fr.), are terms which show that the art of printing came directly from France to England.

[61]Chase (chassis, frame, Fr.), quoin (coin, wedge, Fr.), are terms which show that the art of printing came directly from France to England.

STILL (Alambic, Fr.;Blase, Germ.); is a chemical apparatus, for vaporizing liquids by heat in one part, called thecucurbit, and condensing the vapours into liquids in another part, called therefrigeratory; the general purpose of both combined being to separate the more volatile fluid particles from the less volatile. In its simplest form, it consists of a retort and a receiver, or of a pear-shaped matrass and a capital, furnished with a slanting tube for conducting away the condensed vapours in drops; whence the termstill, from the Latin verbstillare, to drop. Its chief employment in this country being to eliminate alcohol, of greater or less strength, from fermented wash, I shall devote this article to a description of the stills best adapted to the manufacture of British spirits, referring to chemical authors[62]for those fitted for peculiar objects.[62]The treatises of Le Normand and Dubrunfaut may also be consulted. The French stills are in general so much complicated with a great many small pipes and passages, as to be unfit for distilling the glutinous wash of grains.In respect of rapidity and extent of work, stills had attained to an extraordinary pitch of perfection in Scotland about thirty years ago, when legislative wisdom thought fit to levy the spirits duty, per annum, from each distiller, according to the capacity of his still. It having been shown, in a report presented to the House of Commons in 1799, that an 80-gallon still could be worked off in eight minutes, this fact was made the basis of a new fiscal law, on the supposition that the maximum of velocity had been reached. But, instigated by the hopes of enormous gains at the expense of the revenue, the distillers soon contrived to do the same thing in three minutes, by means of broad-bottomed shallow stills, with stirring-chains, and lofty capitals. In the year 1815, that preposterous law, which encouraged fraud and deteriorated the manufacture, was repealed. The whiskey duties having been since levied, independently of the capacity of the still, upon the quantity produced, such rapid operations have been abandoned, and processes of economy in fuel, and purity in product, have been sought after.One of the greatest improvements in modern distilleries, is completing the analysis of crude spirit at one operation. Chemists had been long familiar with the contrivance of Woulfe, for impregnating with gaseous matter, water contained in a range of bottles; but they had not thought of applying that plan to distillation, when Edouard Adam, an illiterate workman of Montpellier, after hearing accidentally a chemical lecture upon that apparatus, bethought himself of converting it into a still. He caused the boiling-hot vapours to chase the spirits successively out of one bottle into another, so as to obtain in the successive vessels alcohol of any desired strength and purity, “at one and the same heat.” He obtained a patent for this invention in 1801, and was soon afterwards enabled, by his success on the small scale, to set up in his native city a magnificent distillery, which excited the admiration of all the practical chemists of that day. In November, 1805, he obtained a certificate of certain improvements for extracting from wine, at one process, the whole of its alcohol. Adam was so overjoyed, after making his first experiments, that he ran about the streets of Montpellier, telling every body of the surprising results of his invention. Several competitors soon entered the lists with him, especially Solimani, professor of chemistry in that city, and IsaacBerard, distiller in the department of Gard; who, having contrived other forms of continuous stills, divided the profits with the first inventor.The principles of spirituous distillation may be stated as follows:—The boiling point of alcohol varies with its density or strength, in conformity with the numbers in the following table:—Specificgravity.Boiling point,byFahrenheit’sscale.0·7939168·5°0·8034168·00·8118168·50·8194169·00·8265172·50·8332173·50·8397175·00·8458177·00·8518179·00·8875181·00·8631183·00·8765187·00·8892190·00·9013194·00·9126197·00·9234199·00·9335201·0See also the table underAlcohol,page 16.Hence, the lower the temperature of the spirituous vapour which enters the refrigeratory apparatus, the stronger and purer will the condensed spirit be; because the offensive oils, which are present in the wash or wine, are less volatile than alcohol, and are brought over chiefly with the aqueous vapour. A perfect still should, therefore, consist of three distinct members; first, the cucurbit, or kettle; second, the rectifier, for intercepting more or less of the watery and oily particles; and third, the refrigerator, or condenser of the alcoholic vapours.These principles are illustrated in the construction of the still represented infigs.1057,1058,1059,1060,1061.; in which the resources of the most refined French stills are combined with a simplicity and solidity suited to the grain distilleries of the United Kingdom. Three principal objects are obtained by the arrangement here shown; first, the extraction from fermented wort or wine, at one operation, of a spirit of any desired cleanness and strength; second, great economy of time, labour, and fuel; third, freedom from all danger of blowing up or boiling over, by mismanaged firing. When a combination of water, alcohol, and essential oil, in the state of vapour, is passed upwards through a series of winding passages, maintained at a determinate degree of heat, between 170° and 180°, the alcohol alone, in any notable proportion, will retain the elastic form, and will proceed onwards into the refrigeratory tube, in which the said passages terminate; while the water and the oil will be in a great measure condensed, arrested, and thrown back into the body of the still, to be discharged with the effete residuum.The system of passages or channels, represented infig.1058., is so contrived as to bring the mingled vapours which rise from the alembica, into ample and intimate contact with metallic surfaces, maintained, in a water-bath, at a temperature self-regulated by a heat-governor. SeeThermostat.Alembics and stillsThe neck of the alembic tapers upwards, as shown atb,fig.1057.; and atc,fig.1058., it enters the bottom, or ingress vestibule, of the rectifierc,f.fis its top or egress vestibule, which communicates with the bottom one by parallel cases or rectangular channelsd,d,d, of which the width is small, compared with the length and height. These cases are open at top and bottom, where they are soldered or riveted into a general frame within the cavity, enclosed by the two coversf,c, which are secured round their edgese,e,e,e, with bolts and packing. Each case is occupied with a numerous series of shelves or trays, placed at small distances over each other, in a horizontal or slightly inclined position, of which a side view is given infig.1059., and cross sections atd,d,d,fig.1058.Each shelf is turned up a little at the two edges, and at one end, but sloped down at the other end, that the liquor admitted at the top may be made to flow slowly backwards and forwards in its descent through the system of shelves or trays, as indicated by the darts and spouts infig.1059.The shelves of each case are framed together by two or more vertical metallic rods, which pass down through them, and are fixed to each shelf by solder, or by screw-nuts. By this means, if the coverf, be removed, the sets of shelves may be readily lifted out of the cases and cleaned; for which reason they are calledmovable.The intervalsi,i,i,fig.1058., between the cases, are left for the free circulation of the water contained in the bath-vesselg,g; these intervals being considerably narrower than the cases.Fig.1060.represents in plan the surface of the rectifying cistern, shown in two different sections infigs.1058.and1059.h,k,figs.1058.and1060., is the heat-governor,shaped somewhat like a pair of tongs. Each leg is a compound bar, consisting of a flat bar or ruler of steel, and one of brass alloy, riveted facewise together, having their edges up and down. The links, atk, are joined to the free ends of these compound bars, which, receding by increase and approaching by decrease of temperature, act by a lever on the stopcockl, fixed to the pipe of a cold-water back, and are so adjusted by a screw-nut, that whenever the water in the bath vesselg,g, rises above the desired temperature, cold water will be admitted, through the stopcockl, and pipen, into the bottom of the cistern, and will displace the over-heated water by the overflow-pipem. Thus a perfect equilibrium of caloric may be maintained, and alcoholic vapour of correspondent uniformity transmitted to the refrigeratory.Fig.1061.is the cold condenser, of similar construction to the rectifier,fig.1058.; only the water cells should be here larger in proportion to the vapour channelsd,d. This refrigeratory system will be found very powerful, and it presents the great advantage of permitting its interior to be readily inspected and cleansed. It is best made of laminated tin, hardened with a little copper alloy.The mode of working the preceding apparatus will be understood by the following instructions. Into the alembic,a, let as much fermented liquor be admitted as will protect its bottom from being injured by the fire, reserving the main body in the charging-back. Whenever the ebullition in the alembic has raised the temperature of the water-bathg,g, to the desired pitch, whether that be 170°, 175°, or 180°, the thermostatic instrument is to be adjusted by its screw-nut, and then the communication with the charging-back is to be opened by moving the index of the stopcock o, over a proper portion of its quadrantal arch. The wash will now descend in a slender equable stream, through the pipeo,f, thence spread into the horizontal tubep,p, and issue from the orifices of distribution, as seen in the figure, into the respective flat trays or spouts. The manner of its progress is seen for one set of trays, infig.1059.The direction of the stream in each shelf is evidently the reverse of that in the shelf above and below it; the turned-up end of one shelf corresponding to the discharge slope of its neighbour.By diffusing the cool wash or wine in a thin film over such an ample range of surfaces, the constant tendency of the bath to exceed the proper limit of temperature is counteracted to the utmost, without waste of time or fuel; for the wash itself,in transitu, becomes boiling-hot, and experiences a powerful steam distillation. By this arrangement a very moderate influx of cold water, through the thermostatic stopcock, suffices to temper the bath; such an extensive vaporization of the wash producing a far more powerful refrigerant influence than its simple heating to ebullition. It deserves to be remarked, that the maximum distillatory effect, or the bringing over the greatest quantity of pure spirits in the least time, and with the least labour and fuel, is here accomplished without the least steam pressure in the alembic; for the passages areall pervious to the vapour; whereas, in almost every wash-still heretofore contrived for similar purposes, the spirituous vapours must force their way through successive layers of liquid, the total pressure produced by which causes undue elevation of temperature, and obstruction to the process. Whatever supplementary refrigeration of the vapours in their passage through the bath may be deemed proper, will be administered by the thermostatic regulator.Towards the end of the process, after all the wash has entered the alembic, it may be sometimes desirable, for the sake of despatch, to modify the thermostat, by its adjusting-screw, so that the bath may take a higher temperature, and allow the residuary feints to run rapidly over, into a separate cistern. This weak fluid may be pumped back into the alembic, as the preliminary charge of a fresh operation.The above plan of a water-bath regulated by the thermostat, may be used simply as a rectifying cistern, without transmitting the spirit or wash down through it. The series of shelves will cause the vapours from the still to impinge against a most extensive system of metallic surfaces, maintained at a steady temperature, whereby their watery and crude constituents will be condensed and thrown back, while their fine alcoholic particles will proceed forwards to the refrigeratory. Any ordinary still may be readily converted into this self-rectifying form, by merely interposing the cistern,fig.1058., between the alembic and the worm-tub. The leading novelty of the present invention is themovablesystem of shelves or trays, enclosed in metallic cases, separated by water, combined with the thermostatic regulator. By this combination, any quality of spirits may be procured at one step from wash or wine, by an apparatus, simple, strong and easily kept in order.The empyreumatic taint which spirits are apt to contract from the action of the naked fire on the bottom of the still, may be entirely prevented by the use of a bath of potash lye,p,p,fig.1057.; for thus a safe and effectual range of temperature, of 300° F., may be conveniently obtained. The still may also be used without the bath vessel.StillMr. D. T. Shears, of Southwark, obtained a patent in March, 1830, for certain improvements and additions to stills, which are ingenious. They are founded upon a previous patent, granted to Joseph Corty, in 1818; a section of whose contrivance is shown infig.1062., consisting of a first stilla, a second stillb, a connecting tubec, from the one end to the other, and the tubed, which leads from the second still-head down through the bent tubee,e, to the lower part of the condensing apparatus.The original improvements described under Corty’s patent, consisted further, in placing boxesf,f,f, of the condensing apparatus in horizontal positions, and at a distance from each other, in order that the vapour might ascend through them, for the purpose of discharging the spirit by the top tubeg, and pipeh, into the worm, in a highly rectified or concentrated state. In each of the boxesf, there is a convex plate or inverted dishi,i,i, and the vapour in rising from the tubee, strikes against the concave or under part of the first dish, and then escapes round its edges, and over its convex surface, to the under part of the second dish, and so on to the top, the condensed part of the vapour flowing down again into the still, and the spirit passing off by the pipeh, at top; and as the process of condensation will be assisted by cooling the vapour as it rises, cold water is made to flow over the tops of the boxesf, from a cockk, and through small channels or tubes on the sides of the boxes, and is ultimately discharged by the pipel, at bottom.Peculiarly shaped tubeFig.1063.represents a peculiarly shaped tubea, through which the spirit is described as passing after leaving the end of the worm atb, which tube is open to the atmosphericair atz;c, is the passage through which the carbonic acid gas is described as escaping into the vessel of waterd.StillStillNow the improvements claimed under the present patent, are exhibited infigs.1064,1065, and1066.Fig.1064.represents the external appearance of a still, the head of which is made very capacious, to guard against over-boiling by any mismanagement of the fire;fig.1065.is the same, partly in section. On the top of the still-head is formed the first-described rectifying apparatus, or series of condensing boxes. The vapour from the body of the still filling the head, meets with the first check from the dish or lower vesseli, and after passing under its edges, ascends and strikes against the lower part of the second dish or vesseli, and so on, till it ultimately leaves the still-head by the pipe at top.This part of the apparatus is slightly altered from the former, by the substitution of hollow convex vessels, instead of the inverted dishes before described, which vessels have rims descending from their under surfaces, for the purpose of retaining the vapour. The cold water, which, as above described, flowed over the tops of the boxesf, for the purpose of cooling them, now flows also through the hollow convex vesselsi, within the boxes, and by that means greatly assists the refrigerating process, by which the aqueous parts of the vapour are more readily condensed, and made to fall down and flow back again into the body of the still, while the spirituous parts pass off at top to the worm, in a very high state of rectification.After the water employed for the refrigeration has passed over all the boxes, and through all the vessels, it is carried off by the pipem, through the vesseln, called the wash-heater; that is, the vessel in which the wash is placed previous to introducing it into the still. The pipem, is coiled round in the lower part of the vesseln, in order that the heated water may communicate its caloric to the wash, instead of losing the heat by allowing the water to flow away. After the heated water has made several turns round the wash heater, it passes out at the curved pipeo, which is bent up, in order to keep the coils of the pipe within always full of water.Instead of the coiled pipen, last described, the patentee proposes sometimes to pass the hot water into a chamber in a tub or wooden vessel, as atn, infig.1061., in which the wash to be heated occupies the upper part of the vessel, and is separated from the lower part by a thin metallic partition.The swan-neckh,figs.1064.and1065., which leads from the head of the still, conducts the spirit from the still through the wash-heater, where it becomes partially cooled, and gives out its heat to the wash; and from thence the spirit passes to the worm tub, and being finally condensed, is passed through a safety tube, as (fig.1058.) before described, and by the funnel is conducted into the cask below.StillShould any spirit rise in the wash-heater during the above operation, it will be carried down to the worm by the neckp, and coiled pipe, and discharged at its lower end; or it may be passed into the still-head, as shown infig.1062.A patent was obtained by Mr. Æneas Coffey, in August, 1830, for a still, which has been since mounted in several distilleries. It is economical in fuel, labour, and time, but is said not to produce a clean spirit, without peculiar attention.The apparatus is represented infig.1067.a,b,c,d, is a sectional view of that part of the still wherein the wash is deprived of its alcohol, and the vapours analyzed. It is described as consisting of a chamber or vessela, with the vertical chamberb,c, placed above it; the lower half of this chamber is divided into compartments by horizontalplatese,e,e, of thin copper or other metal; each of these plates is turned down at one side, until it nearly touches the plate next underneath it, as shown in the figure; thus leaving a passage throughout the whole of them, by which any liquid falling on the top plate may descend into the next under it, and from that to the third, and so on, from plate to plate, at the alternate ends, until it arrives at the last plate, wherein it falls into the vessela, by the pipef; each of these plates is furnished with several light valves, opening upwards, through which any steam or vapour may ascend; it may also be perforated with holes, but they must not be so numerous or so large as to allow of all the steam passing through them without raising the valves;c, is a pipe by which the alcoholic vapour, after it has been analyzed, and has acquired the proper strength, is conducted into the vesseld, which is made perfectly close; the vapour will here be condensed on the surface of the pipeg,g,g; from this chamber it will descend in a liquid state into the pipeh, whence it may be conducted to a worm or refrigerator, to be cooled in the ordinary way;i, is a vessel through which the spent wash flows, after being operated upon in the distilling apparatus, and is discharged in a state of ebullition;j, is a vessel or chamber containing the wash to be distilled. A force pump may be substituted, to force the wash through the pipesk, and distilling apparatus, with the velocity required.The patentee states that it is requisite the wash should be passed through the pipek, with sufficient velocity and force, so as to prevent the deposition of sediment in the pipe; the wash in its passage through the pipek, will gradually become increased in temperature as it passes through the spent wash in the chamber, and the close vesseld, until it is discharged nearly at the boiling point on the upper plate in the chamber, where it comes in contact with the vapours arising from the vessela.It is to be observed, that the wort does not reach the boiling point while in the pipek,k; to ascertain which, a thermometer is placed on the pipe, and by increasing or diminishing the quantity of wash, its temperature may be regulated. The wash, after being discharged from the pipek, descends from plate to plate as before mentioned, at which time a supply of steam from a boiler, or generator is admitted into the apparatus, through the pipe.The lower part of this pipe in the vessela, is pierced with a number of small holes, so as to spread the steam over the vessel; it then rises upwards, passing through the plate by the small holes and valves, and through the stratum or sheet of wash flowing over them; the wash, as it descends, gives out a portion of its alcohol to the steam, as it passes over every plate, until it is entirely deprived of its spirit, which it will generally do by the time it arrives at the 7th or 8th plate; but it is better to employ a greater number, to guard against accidents or neglect.A small steam pipe rises from the chambera, with its upper end opening into the box or chamber; into this chamber the end of a worm projects from the cistern of cold water; the steam rising up the pipe is nearly all condensed in the worm, and flows back into the chambera, by the pipe. The small portion of the steam uncondensed, is allowed to escape at the upper end of the worm, and the flame of a small lamp or taper is to be constantly kept over the orifice; when, should the least quantity of alcohol descend with the wash into the chambera, it will rise with the steam through the pipe and worm, and immediately take fire from the flame of the lamp or taper, thereby warning the attendant to increase the supply of steam or diminish the quantity of wash, as may seem necessary.Cheap stillI shall conclude this article with a description of thecheap stillwhich is commonly employed by the chemists in Berlin for rectifying alcohol.a, is the ash-pit;b, the fireplace;c,c, the flues, which go spirally round the sides of the cucurbitd;e, the capital, made of block tin, and furnished with a brass edge, which fits tight to a corresponding edge on the mouth ofd;f,f, the slanting pipes of the capital;g, the oval refrigeratory, made of copper;h, the water-gauge glass tube;i, a stopcock for emptying the vessel;k, do., for drawing off the hot water from the surface;l, tube for the supply of cold water. A double cylinder of tin is placed in the refrigeratory, of which the outer onem,m, stands upon three feet, and is furnished with a discharge pipen. The inner oneo,o, which is open above, receives cold water through the pipep, and lets the warm water flow off through the short tubeq, into the refrigeratory. In the narrow space between the two cylinders, the vapours proceeding from the capital are condensed, and pass off in the liquid state throughn. The refrigeratory is made oval, in order to receive two condensers alongside of each other in the line of the longer axis; though only one, and that in the middle, is represented in the figure.

[62]The treatises of Le Normand and Dubrunfaut may also be consulted. The French stills are in general so much complicated with a great many small pipes and passages, as to be unfit for distilling the glutinous wash of grains.

In respect of rapidity and extent of work, stills had attained to an extraordinary pitch of perfection in Scotland about thirty years ago, when legislative wisdom thought fit to levy the spirits duty, per annum, from each distiller, according to the capacity of his still. It having been shown, in a report presented to the House of Commons in 1799, that an 80-gallon still could be worked off in eight minutes, this fact was made the basis of a new fiscal law, on the supposition that the maximum of velocity had been reached. But, instigated by the hopes of enormous gains at the expense of the revenue, the distillers soon contrived to do the same thing in three minutes, by means of broad-bottomed shallow stills, with stirring-chains, and lofty capitals. In the year 1815, that preposterous law, which encouraged fraud and deteriorated the manufacture, was repealed. The whiskey duties having been since levied, independently of the capacity of the still, upon the quantity produced, such rapid operations have been abandoned, and processes of economy in fuel, and purity in product, have been sought after.

One of the greatest improvements in modern distilleries, is completing the analysis of crude spirit at one operation. Chemists had been long familiar with the contrivance of Woulfe, for impregnating with gaseous matter, water contained in a range of bottles; but they had not thought of applying that plan to distillation, when Edouard Adam, an illiterate workman of Montpellier, after hearing accidentally a chemical lecture upon that apparatus, bethought himself of converting it into a still. He caused the boiling-hot vapours to chase the spirits successively out of one bottle into another, so as to obtain in the successive vessels alcohol of any desired strength and purity, “at one and the same heat.” He obtained a patent for this invention in 1801, and was soon afterwards enabled, by his success on the small scale, to set up in his native city a magnificent distillery, which excited the admiration of all the practical chemists of that day. In November, 1805, he obtained a certificate of certain improvements for extracting from wine, at one process, the whole of its alcohol. Adam was so overjoyed, after making his first experiments, that he ran about the streets of Montpellier, telling every body of the surprising results of his invention. Several competitors soon entered the lists with him, especially Solimani, professor of chemistry in that city, and IsaacBerard, distiller in the department of Gard; who, having contrived other forms of continuous stills, divided the profits with the first inventor.

The principles of spirituous distillation may be stated as follows:—The boiling point of alcohol varies with its density or strength, in conformity with the numbers in the following table:—

See also the table underAlcohol,page 16.

Hence, the lower the temperature of the spirituous vapour which enters the refrigeratory apparatus, the stronger and purer will the condensed spirit be; because the offensive oils, which are present in the wash or wine, are less volatile than alcohol, and are brought over chiefly with the aqueous vapour. A perfect still should, therefore, consist of three distinct members; first, the cucurbit, or kettle; second, the rectifier, for intercepting more or less of the watery and oily particles; and third, the refrigerator, or condenser of the alcoholic vapours.

These principles are illustrated in the construction of the still represented infigs.1057,1058,1059,1060,1061.; in which the resources of the most refined French stills are combined with a simplicity and solidity suited to the grain distilleries of the United Kingdom. Three principal objects are obtained by the arrangement here shown; first, the extraction from fermented wort or wine, at one operation, of a spirit of any desired cleanness and strength; second, great economy of time, labour, and fuel; third, freedom from all danger of blowing up or boiling over, by mismanaged firing. When a combination of water, alcohol, and essential oil, in the state of vapour, is passed upwards through a series of winding passages, maintained at a determinate degree of heat, between 170° and 180°, the alcohol alone, in any notable proportion, will retain the elastic form, and will proceed onwards into the refrigeratory tube, in which the said passages terminate; while the water and the oil will be in a great measure condensed, arrested, and thrown back into the body of the still, to be discharged with the effete residuum.

The system of passages or channels, represented infig.1058., is so contrived as to bring the mingled vapours which rise from the alembica, into ample and intimate contact with metallic surfaces, maintained, in a water-bath, at a temperature self-regulated by a heat-governor. SeeThermostat.

Alembics and stills

The neck of the alembic tapers upwards, as shown atb,fig.1057.; and atc,fig.1058., it enters the bottom, or ingress vestibule, of the rectifierc,f.fis its top or egress vestibule, which communicates with the bottom one by parallel cases or rectangular channelsd,d,d, of which the width is small, compared with the length and height. These cases are open at top and bottom, where they are soldered or riveted into a general frame within the cavity, enclosed by the two coversf,c, which are secured round their edgese,e,e,e, with bolts and packing. Each case is occupied with a numerous series of shelves or trays, placed at small distances over each other, in a horizontal or slightly inclined position, of which a side view is given infig.1059., and cross sections atd,d,d,fig.1058.Each shelf is turned up a little at the two edges, and at one end, but sloped down at the other end, that the liquor admitted at the top may be made to flow slowly backwards and forwards in its descent through the system of shelves or trays, as indicated by the darts and spouts infig.1059.The shelves of each case are framed together by two or more vertical metallic rods, which pass down through them, and are fixed to each shelf by solder, or by screw-nuts. By this means, if the coverf, be removed, the sets of shelves may be readily lifted out of the cases and cleaned; for which reason they are calledmovable.

The intervalsi,i,i,fig.1058., between the cases, are left for the free circulation of the water contained in the bath-vesselg,g; these intervals being considerably narrower than the cases.

Fig.1060.represents in plan the surface of the rectifying cistern, shown in two different sections infigs.1058.and1059.h,k,figs.1058.and1060., is the heat-governor,shaped somewhat like a pair of tongs. Each leg is a compound bar, consisting of a flat bar or ruler of steel, and one of brass alloy, riveted facewise together, having their edges up and down. The links, atk, are joined to the free ends of these compound bars, which, receding by increase and approaching by decrease of temperature, act by a lever on the stopcockl, fixed to the pipe of a cold-water back, and are so adjusted by a screw-nut, that whenever the water in the bath vesselg,g, rises above the desired temperature, cold water will be admitted, through the stopcockl, and pipen, into the bottom of the cistern, and will displace the over-heated water by the overflow-pipem. Thus a perfect equilibrium of caloric may be maintained, and alcoholic vapour of correspondent uniformity transmitted to the refrigeratory.

Fig.1061.is the cold condenser, of similar construction to the rectifier,fig.1058.; only the water cells should be here larger in proportion to the vapour channelsd,d. This refrigeratory system will be found very powerful, and it presents the great advantage of permitting its interior to be readily inspected and cleansed. It is best made of laminated tin, hardened with a little copper alloy.

The mode of working the preceding apparatus will be understood by the following instructions. Into the alembic,a, let as much fermented liquor be admitted as will protect its bottom from being injured by the fire, reserving the main body in the charging-back. Whenever the ebullition in the alembic has raised the temperature of the water-bathg,g, to the desired pitch, whether that be 170°, 175°, or 180°, the thermostatic instrument is to be adjusted by its screw-nut, and then the communication with the charging-back is to be opened by moving the index of the stopcock o, over a proper portion of its quadrantal arch. The wash will now descend in a slender equable stream, through the pipeo,f, thence spread into the horizontal tubep,p, and issue from the orifices of distribution, as seen in the figure, into the respective flat trays or spouts. The manner of its progress is seen for one set of trays, infig.1059.The direction of the stream in each shelf is evidently the reverse of that in the shelf above and below it; the turned-up end of one shelf corresponding to the discharge slope of its neighbour.

By diffusing the cool wash or wine in a thin film over such an ample range of surfaces, the constant tendency of the bath to exceed the proper limit of temperature is counteracted to the utmost, without waste of time or fuel; for the wash itself,in transitu, becomes boiling-hot, and experiences a powerful steam distillation. By this arrangement a very moderate influx of cold water, through the thermostatic stopcock, suffices to temper the bath; such an extensive vaporization of the wash producing a far more powerful refrigerant influence than its simple heating to ebullition. It deserves to be remarked, that the maximum distillatory effect, or the bringing over the greatest quantity of pure spirits in the least time, and with the least labour and fuel, is here accomplished without the least steam pressure in the alembic; for the passages areall pervious to the vapour; whereas, in almost every wash-still heretofore contrived for similar purposes, the spirituous vapours must force their way through successive layers of liquid, the total pressure produced by which causes undue elevation of temperature, and obstruction to the process. Whatever supplementary refrigeration of the vapours in their passage through the bath may be deemed proper, will be administered by the thermostatic regulator.

Towards the end of the process, after all the wash has entered the alembic, it may be sometimes desirable, for the sake of despatch, to modify the thermostat, by its adjusting-screw, so that the bath may take a higher temperature, and allow the residuary feints to run rapidly over, into a separate cistern. This weak fluid may be pumped back into the alembic, as the preliminary charge of a fresh operation.

The above plan of a water-bath regulated by the thermostat, may be used simply as a rectifying cistern, without transmitting the spirit or wash down through it. The series of shelves will cause the vapours from the still to impinge against a most extensive system of metallic surfaces, maintained at a steady temperature, whereby their watery and crude constituents will be condensed and thrown back, while their fine alcoholic particles will proceed forwards to the refrigeratory. Any ordinary still may be readily converted into this self-rectifying form, by merely interposing the cistern,fig.1058., between the alembic and the worm-tub. The leading novelty of the present invention is themovablesystem of shelves or trays, enclosed in metallic cases, separated by water, combined with the thermostatic regulator. By this combination, any quality of spirits may be procured at one step from wash or wine, by an apparatus, simple, strong and easily kept in order.

The empyreumatic taint which spirits are apt to contract from the action of the naked fire on the bottom of the still, may be entirely prevented by the use of a bath of potash lye,p,p,fig.1057.; for thus a safe and effectual range of temperature, of 300° F., may be conveniently obtained. The still may also be used without the bath vessel.

Still

Mr. D. T. Shears, of Southwark, obtained a patent in March, 1830, for certain improvements and additions to stills, which are ingenious. They are founded upon a previous patent, granted to Joseph Corty, in 1818; a section of whose contrivance is shown infig.1062., consisting of a first stilla, a second stillb, a connecting tubec, from the one end to the other, and the tubed, which leads from the second still-head down through the bent tubee,e, to the lower part of the condensing apparatus.

The original improvements described under Corty’s patent, consisted further, in placing boxesf,f,f, of the condensing apparatus in horizontal positions, and at a distance from each other, in order that the vapour might ascend through them, for the purpose of discharging the spirit by the top tubeg, and pipeh, into the worm, in a highly rectified or concentrated state. In each of the boxesf, there is a convex plate or inverted dishi,i,i, and the vapour in rising from the tubee, strikes against the concave or under part of the first dish, and then escapes round its edges, and over its convex surface, to the under part of the second dish, and so on to the top, the condensed part of the vapour flowing down again into the still, and the spirit passing off by the pipeh, at top; and as the process of condensation will be assisted by cooling the vapour as it rises, cold water is made to flow over the tops of the boxesf, from a cockk, and through small channels or tubes on the sides of the boxes, and is ultimately discharged by the pipel, at bottom.

Peculiarly shaped tube

Fig.1063.represents a peculiarly shaped tubea, through which the spirit is described as passing after leaving the end of the worm atb, which tube is open to the atmosphericair atz;c, is the passage through which the carbonic acid gas is described as escaping into the vessel of waterd.

Still

Now the improvements claimed under the present patent, are exhibited infigs.1064,1065, and1066.Fig.1064.represents the external appearance of a still, the head of which is made very capacious, to guard against over-boiling by any mismanagement of the fire;fig.1065.is the same, partly in section. On the top of the still-head is formed the first-described rectifying apparatus, or series of condensing boxes. The vapour from the body of the still filling the head, meets with the first check from the dish or lower vesseli, and after passing under its edges, ascends and strikes against the lower part of the second dish or vesseli, and so on, till it ultimately leaves the still-head by the pipe at top.

This part of the apparatus is slightly altered from the former, by the substitution of hollow convex vessels, instead of the inverted dishes before described, which vessels have rims descending from their under surfaces, for the purpose of retaining the vapour. The cold water, which, as above described, flowed over the tops of the boxesf, for the purpose of cooling them, now flows also through the hollow convex vesselsi, within the boxes, and by that means greatly assists the refrigerating process, by which the aqueous parts of the vapour are more readily condensed, and made to fall down and flow back again into the body of the still, while the spirituous parts pass off at top to the worm, in a very high state of rectification.

After the water employed for the refrigeration has passed over all the boxes, and through all the vessels, it is carried off by the pipem, through the vesseln, called the wash-heater; that is, the vessel in which the wash is placed previous to introducing it into the still. The pipem, is coiled round in the lower part of the vesseln, in order that the heated water may communicate its caloric to the wash, instead of losing the heat by allowing the water to flow away. After the heated water has made several turns round the wash heater, it passes out at the curved pipeo, which is bent up, in order to keep the coils of the pipe within always full of water.

Instead of the coiled pipen, last described, the patentee proposes sometimes to pass the hot water into a chamber in a tub or wooden vessel, as atn, infig.1061., in which the wash to be heated occupies the upper part of the vessel, and is separated from the lower part by a thin metallic partition.

The swan-neckh,figs.1064.and1065., which leads from the head of the still, conducts the spirit from the still through the wash-heater, where it becomes partially cooled, and gives out its heat to the wash; and from thence the spirit passes to the worm tub, and being finally condensed, is passed through a safety tube, as (fig.1058.) before described, and by the funnel is conducted into the cask below.

Still

Should any spirit rise in the wash-heater during the above operation, it will be carried down to the worm by the neckp, and coiled pipe, and discharged at its lower end; or it may be passed into the still-head, as shown infig.1062.

A patent was obtained by Mr. Æneas Coffey, in August, 1830, for a still, which has been since mounted in several distilleries. It is economical in fuel, labour, and time, but is said not to produce a clean spirit, without peculiar attention.

The apparatus is represented infig.1067.a,b,c,d, is a sectional view of that part of the still wherein the wash is deprived of its alcohol, and the vapours analyzed. It is described as consisting of a chamber or vessela, with the vertical chamberb,c, placed above it; the lower half of this chamber is divided into compartments by horizontalplatese,e,e, of thin copper or other metal; each of these plates is turned down at one side, until it nearly touches the plate next underneath it, as shown in the figure; thus leaving a passage throughout the whole of them, by which any liquid falling on the top plate may descend into the next under it, and from that to the third, and so on, from plate to plate, at the alternate ends, until it arrives at the last plate, wherein it falls into the vessela, by the pipef; each of these plates is furnished with several light valves, opening upwards, through which any steam or vapour may ascend; it may also be perforated with holes, but they must not be so numerous or so large as to allow of all the steam passing through them without raising the valves;c, is a pipe by which the alcoholic vapour, after it has been analyzed, and has acquired the proper strength, is conducted into the vesseld, which is made perfectly close; the vapour will here be condensed on the surface of the pipeg,g,g; from this chamber it will descend in a liquid state into the pipeh, whence it may be conducted to a worm or refrigerator, to be cooled in the ordinary way;i, is a vessel through which the spent wash flows, after being operated upon in the distilling apparatus, and is discharged in a state of ebullition;j, is a vessel or chamber containing the wash to be distilled. A force pump may be substituted, to force the wash through the pipesk, and distilling apparatus, with the velocity required.

The patentee states that it is requisite the wash should be passed through the pipek, with sufficient velocity and force, so as to prevent the deposition of sediment in the pipe; the wash in its passage through the pipek, will gradually become increased in temperature as it passes through the spent wash in the chamber, and the close vesseld, until it is discharged nearly at the boiling point on the upper plate in the chamber, where it comes in contact with the vapours arising from the vessela.

It is to be observed, that the wort does not reach the boiling point while in the pipek,k; to ascertain which, a thermometer is placed on the pipe, and by increasing or diminishing the quantity of wash, its temperature may be regulated. The wash, after being discharged from the pipek, descends from plate to plate as before mentioned, at which time a supply of steam from a boiler, or generator is admitted into the apparatus, through the pipe.

The lower part of this pipe in the vessela, is pierced with a number of small holes, so as to spread the steam over the vessel; it then rises upwards, passing through the plate by the small holes and valves, and through the stratum or sheet of wash flowing over them; the wash, as it descends, gives out a portion of its alcohol to the steam, as it passes over every plate, until it is entirely deprived of its spirit, which it will generally do by the time it arrives at the 7th or 8th plate; but it is better to employ a greater number, to guard against accidents or neglect.

A small steam pipe rises from the chambera, with its upper end opening into the box or chamber; into this chamber the end of a worm projects from the cistern of cold water; the steam rising up the pipe is nearly all condensed in the worm, and flows back into the chambera, by the pipe. The small portion of the steam uncondensed, is allowed to escape at the upper end of the worm, and the flame of a small lamp or taper is to be constantly kept over the orifice; when, should the least quantity of alcohol descend with the wash into the chambera, it will rise with the steam through the pipe and worm, and immediately take fire from the flame of the lamp or taper, thereby warning the attendant to increase the supply of steam or diminish the quantity of wash, as may seem necessary.

Cheap still

I shall conclude this article with a description of thecheap stillwhich is commonly employed by the chemists in Berlin for rectifying alcohol.a, is the ash-pit;b, the fireplace;c,c, the flues, which go spirally round the sides of the cucurbitd;e, the capital, made of block tin, and furnished with a brass edge, which fits tight to a corresponding edge on the mouth ofd;f,f, the slanting pipes of the capital;g, the oval refrigeratory, made of copper;h, the water-gauge glass tube;i, a stopcock for emptying the vessel;k, do., for drawing off the hot water from the surface;l, tube for the supply of cold water. A double cylinder of tin is placed in the refrigeratory, of which the outer onem,m, stands upon three feet, and is furnished with a discharge pipen. The inner oneo,o, which is open above, receives cold water through the pipep, and lets the warm water flow off through the short tubeq, into the refrigeratory. In the narrow space between the two cylinders, the vapours proceeding from the capital are condensed, and pass off in the liquid state throughn. The refrigeratory is made oval, in order to receive two condensers alongside of each other in the line of the longer axis; though only one, and that in the middle, is represented in the figure.

STOCKING MANUFACTURE. SeeHosiery.

STONE, is earthy matter, condensed into so hard a state as to yield only to the blows of a hammer, and therefore well adapted to the purposes of building. Such was the care of the antients to provide strong and durable materials for their public edifices, that but for the desolating hands of modern barbarians, in peace and in war, most of the temples and other public monuments of Greece and of Rome would have remained perfect at the present day, uninjured by the elements during 2000 years. The contrast, in this respect, of the works of modern architects, especially in Great Britain, is very humiliating to those who boast so loudly of social advancement; for there is scarcely a public building of recent date, which will be in existence one thousand years hence. Many of the most splendid works of modern architecture are hastening to decay, in what may be justly called the very infancy of their existence, if compared with the date of those erected in antient Italy, Greece, and Egypt. This is remarkably the case with the three bridges of London, Westminster, and Blackfriars; the foundations of which began to perish most visibly in the very lifetime of their constructors. Every stone intended for a durable edifice, ought to be tested as to its durability, by immersion in a saturated solution of sulphate of soda, and exposure during some days to the air. The crystallization which ensues in its interior, will cause the same disintegration of its substance which frost would occasion in a series of years.

Artificial stone makerFigs. 1069, 1070 enlarged(155 kB)Artificial stone makerSTONE, ARTIFICIAL, for statuary and other decorations of architecture, has been made for several years with singular success at Berlin, by Mr. Feilner. His materials are nearly the same with those of English pottery; and the plastic mass is fashioned either in moulds, or by hand. His kilns, which are peculiar in form, and economical in fuel, deserve to be generally known.Figs.1069.and1070.represent his round kiln;fig.1069.being an oblique section in the lineA,B,C, offig.1070., which is a ground plan in the lineD,a,b,E, offig.1069.The inner circular spacec, covered with the elliptical arch, is filled with the figures to be baked, set upon brick supports. The hearth is a few feet above the ground; and there are steps before the doord, for the workmen to mount by, in charging the kiln. The fire is applied on the four sides under the hearth. The flame of each passes along the straight fluesf i,f i, andf k. In the second annular flueg,g, as also in the thirdl,l, the flame of each fire is kept apart, being separated from the adjoining, by the stoneshandm. In the fourth fluen, the flames again come together, as also ino, and ascend by the middle opening. Besides this large orifice, there are several small holes,p,p, in the hearth over the above flues, to lead the flames from the other points into contact with the various articles. There are also channelsq,q, in the sides, enclosed by thin wallsr, to promote the equable distribution of the heat; and these are placed right over the first fire-fluese. Thepartitionsr, are perforated with many holes, through which, as well as from their tops, the flame may be directed inwards and downwards;sare the vents for carrying off the flames into the upper spaceu, which is usually left empty. These vents can be closed by iron damper-plates, pushed in through the side-slits of the dome.t,t, are peep-holes, for observing the state of ignition in the furnace; but they are most commonly bricked up.Fig.1071.is a vertical section, andfig.1072.a plan, of an excellent kiln for baking clay to a stony consistence, for the above purpose, or for burning fire-bricks.A, is the lower;B, the middle;C, the upper kiln; andD, the hood, terminating in the chimneyE.a,a, is the ash-pit;b,b, the vault for raking out the ashes; it is covered with an iron doorc.d, is the peep-hole, filled with a clay stopper;e, is the fireplace;f,f, a vent in the middle of each arch;g,g, flues at the sides of the arches, situated between the two fireplaces;h,i,k, are apertures for introducing the articles to be baked;l, a grate for the fire in the uppermost kiln;m, the ash-pit;n, the fire-door;o, openings through which the flames of a second fire are thrown in. At first, only the ground kilnA, is fired, with cleft billets of pine-wood, introduced at the openinge; when this is finished, the second is fired; and then the third, in like manner. This kiln is very like the porcelain kiln of Sèvres, and is employed in many places for baking stoneware.Mr. Keene obtained a patent, about a year ago, for making a factitious stone-paste in the following way:—He dissolves one pound of alum in a gallon of water, and in this solution he soaks 84 pounds of gypsum calcined in small lumps. He exposes these lumps in the open air for about eight days, till they become apparently dry, and then calcines them in an oven at a dull-red heat. The waste heat of a coke oven is well adapted for this purpose. (SeePitcoal, coking of.) These lumps, being ground and sifted, afford a fine powder, which, when made up into a paste with the proper quantity of water, forms the petrifying ground. The mass soon concretes, and after being brushed over with a thin layer of the petrifying paste, may be polished with pumice, &c., in the usual way. It then affords a body of great compactness and durability. If half a pound of copperas be added to the solution of the alum, the gypsum paste, treated as above, has a fine cream or yellow colour. This stone stands the weather well.

Artificial stone makerFigs. 1069, 1070 enlarged(155 kB)

Figs. 1069, 1070 enlarged(155 kB)

Artificial stone maker

STONE, ARTIFICIAL, for statuary and other decorations of architecture, has been made for several years with singular success at Berlin, by Mr. Feilner. His materials are nearly the same with those of English pottery; and the plastic mass is fashioned either in moulds, or by hand. His kilns, which are peculiar in form, and economical in fuel, deserve to be generally known.Figs.1069.and1070.represent his round kiln;fig.1069.being an oblique section in the lineA,B,C, offig.1070., which is a ground plan in the lineD,a,b,E, offig.1069.The inner circular spacec, covered with the elliptical arch, is filled with the figures to be baked, set upon brick supports. The hearth is a few feet above the ground; and there are steps before the doord, for the workmen to mount by, in charging the kiln. The fire is applied on the four sides under the hearth. The flame of each passes along the straight fluesf i,f i, andf k. In the second annular flueg,g, as also in the thirdl,l, the flame of each fire is kept apart, being separated from the adjoining, by the stoneshandm. In the fourth fluen, the flames again come together, as also ino, and ascend by the middle opening. Besides this large orifice, there are several small holes,p,p, in the hearth over the above flues, to lead the flames from the other points into contact with the various articles. There are also channelsq,q, in the sides, enclosed by thin wallsr, to promote the equable distribution of the heat; and these are placed right over the first fire-fluese. Thepartitionsr, are perforated with many holes, through which, as well as from their tops, the flame may be directed inwards and downwards;sare the vents for carrying off the flames into the upper spaceu, which is usually left empty. These vents can be closed by iron damper-plates, pushed in through the side-slits of the dome.t,t, are peep-holes, for observing the state of ignition in the furnace; but they are most commonly bricked up.Fig.1071.is a vertical section, andfig.1072.a plan, of an excellent kiln for baking clay to a stony consistence, for the above purpose, or for burning fire-bricks.A, is the lower;B, the middle;C, the upper kiln; andD, the hood, terminating in the chimneyE.a,a, is the ash-pit;b,b, the vault for raking out the ashes; it is covered with an iron doorc.d, is the peep-hole, filled with a clay stopper;e, is the fireplace;f,f, a vent in the middle of each arch;g,g, flues at the sides of the arches, situated between the two fireplaces;h,i,k, are apertures for introducing the articles to be baked;l, a grate for the fire in the uppermost kiln;m, the ash-pit;n, the fire-door;o, openings through which the flames of a second fire are thrown in. At first, only the ground kilnA, is fired, with cleft billets of pine-wood, introduced at the openinge; when this is finished, the second is fired; and then the third, in like manner. This kiln is very like the porcelain kiln of Sèvres, and is employed in many places for baking stoneware.

Mr. Keene obtained a patent, about a year ago, for making a factitious stone-paste in the following way:—He dissolves one pound of alum in a gallon of water, and in this solution he soaks 84 pounds of gypsum calcined in small lumps. He exposes these lumps in the open air for about eight days, till they become apparently dry, and then calcines them in an oven at a dull-red heat. The waste heat of a coke oven is well adapted for this purpose. (SeePitcoal, coking of.) These lumps, being ground and sifted, afford a fine powder, which, when made up into a paste with the proper quantity of water, forms the petrifying ground. The mass soon concretes, and after being brushed over with a thin layer of the petrifying paste, may be polished with pumice, &c., in the usual way. It then affords a body of great compactness and durability. If half a pound of copperas be added to the solution of the alum, the gypsum paste, treated as above, has a fine cream or yellow colour. This stone stands the weather well.

STONEWARE. (Fayence, Fr.;Steingut, Germ.) SeePottery.

STORAX, STYRAX, flows from the twigs and the trunk of theLiquidambar styraciflua, a tree which grows in Louisiana, Virginia, and Mexico. Liquidamber, as this resin is also called, is a brown or ash-gray substance, of the consistence of turpentine, which dries up rapidly, has an agreeable smell, like benzoin, and a bitterish, sharp, burning taste. It dissolves in four parts of alcohol, and affords 1·4 per cent. of benzoic acid.

STOVE (Poële,Calorifère, Fr.;Ofen, Germ.); is a fireplace, more or less close, for warming apartments. When it allows the burning coals to be seen, it is called a stove-grate. Hitherto stoves have rarely been had recourse to in this country for heating our sitting-rooms; the cheerful blaze and ventilation of an open fire being generally preferred. But last winter, by its inclemency, gave birth to a vast multitude of projects for increasing warmth and economizing fuel, many of them eminently insalubrious, by preventing due renewal of the air, and by the introduction of noxious fumes into it. When coke is burned very slowly in an iron box, the carbonic acid gas which is generated, being half as heavy again as the atmospherical air, cannot ascend in the chimney at the temperature of 300° F.; but regurgitates into the apartment through every pore of the stove, and poisons the atmosphere. The large stoneware stoves of France and Germany are free from this vice; because, being fed with fuel from the outside, they cannot produce a reflux of carbonic acid into the apartment, when their draught becomes feeble, as inevitably results from the obscurely burning stoves which have the doors of the fireplace and ash-pit immediately above the hearth-stone.I have recently performed some careful experiments upon this subject, and find that when the fuel is burning so slowly in the stove as not to heat the iron surface above the 250th or 300th degree of Fahr., there is a constant deflux of carbonic acid gas from the ash-pit into the room. This noxious emanation is most easily evinced by applying the beak of a matrass, containing a little Goulard’s extract (solution of subacetate of lead), to a round hole in the door of the ash-pit of a stove in this languid state of combustion. In a few seconds the liquid will become milky, by the reception of carbonic acid gas. I shall be happy to afford ocular demonstration of this fact to any incredulous votary of the pseudo-economical, anti-ventilation, stoves now so much in vogue. There is no mode in which the health and life of a person can be placed in more insidious jeopardy, than by sitting in a room with its chimney closed up with such a choke-damp-vomiting stove.That fuel may be consumed by an obscure species of combustion, with the emission of very little heat, was clearly shown in Sir H. Davy’sResearches on Flame. “The facts detailed on insensible combustion,” says he, “explain why so much more heat is obtained from fuel when it is burned quickly, than slowly; and they show that, in all cases, the temperature of the acting bodies should be kept as high as possible; not only because the general increment of heat is greater, but likewise because those combinations are prevented, which, at lower temperatures, take place without any considerable production of heat. These facts likewise indicate the source of the great error into which experimenters have fallen, in estimating the heat given out in the combustion of charcoal; and they indicate methods by which the temperature may be increased, and the limits to certain methods.” These conclusions are placed in a strong practical light by the following simple experiments:—I set upon the top orifice of a small cylindrical stove, a hemispherical copper pan, containing six pounds of water, at 60° F., and burned briskly under it 31⁄2pounds of coke in an hour; at the end of which time, 41⁄2pounds of water were boiled off. On burning the same weight of cokeslowlyin the same furnace, surmounted by the same pan, in the course of 12 hours, little more than one-half the quantity of water was exhaled. Yet, in the first case, the aerial products of combustion swept so rapidly over the bottom of the pan, as to communicate to it not more than one-fourth of the effective heat which might have been obtained by one of the plans described in the articleEvaporation; while, in the second case, these products moved at least 12 times more slowly across the bottom of the pan, and ought therefore to have been so much the more effective in evaporation, had they possessed the same power or quantity of heat.StoveStoves, when properly constructed, may be employed both safely and advantageously to heat entrance-halls upon the ground story of a house; but care should be taken not to vitiate the air by passing it over ignited surfaces, as is the case with most of the patent stoves now foisted upon the public.Fig.1073.exhibits a vertical section of a stove which has been recommended for power and economy; but it is highly objectionable, as being apt to scorch the air. The flame of the fireA, circulates round the horizontal pipes of cast iron,b b,c c,d d,e e, which receive the external air at the orificeb, and conduct it up through the series, till it issues highly heated atK,L, and may be thence conducted wherever it is wanted. The smoke escapes through the chimneyB. This stove has evidently two prominent faults; first, it heats the air-pipes very unequally,and the undermost far too much; secondly, the air, by the time it has ascended through the zigzag range to the pipee e, will be nearly of the same temperature with it, and will therefore abstract none of its heat. Thus the upper pipes, if there be several in the range, will be quite inoperative, wasting their warmth upon the sooty air.Improved stoveFig.1074.exhibits a transverse vertical section of a far more economical and powerful stove, in which the above evils are avoided. The products of combustion of the fireA, rise up between two brick walls, so as to play upon the bed of tilesB, where, after communicating a moderate heat to the series of slanting pipes whose areas are represented by the small circlesa,a, they turn to the right and left, and circulate round the successive rows of pipesb b,c c,d d,e e, and finally escape at the bottom by the fluesg,g, pursuing a somewhat similar path to that of the burned air among a bench of gas-light retorts. It is known, that two-thirds of the fuel have been saved in the gas-works by this distribution of the furnace. For the purpose of heating apartments, the great object is to supply a vast body of genial air; and, therefore, merely such a moderate fire should be kept up inA, as will suffice to warm all the pipes pretty equably to the temperature of 220° Fahr.; and, indeed, as they are laid with a slight slope, are open to the air at their under ends, and terminate at the upper in a common main pipe or tunnel, they can hardly be rendered very hot by any intemperance of firing. I can safely recommend this stove to my readers. If the tubes be made of stoneware, its construction will cost very little; and they may be made of any size, and multiplied so as to carry off the whole effective heat of the fuel, leaving merely so much of it in the burned air, as to waft it fairly up the chimney.I shall conclude this article by a short extract of a paper which was read before the Royal Society, on the 16th of June, 1836,upon warming and ventilating apartments; a subject to which my mind had been particularly turned at that time, by the Directors of the Customs Fund of Life Assurance, on account of the very general state of indisposition and disease prevailing among those of their officers (nearly 100 in number) engaged on duty in the Long Room of the Custom House, London.“The symptoms of disorder experienced by the several gentlemen (about twenty in number), whom I examined, out of a great many who were indisposed, were of a very uniform character. The following is the result of my researches:—“A sense of tension or fulness of the head, with occasional flushings of the countenance, throbbing of the temples, and vertigo, followed, not unfrequently, with a confusion of ideas, very disagreeable to officers occupied with important and sometimes intricate calculations. A few are affected with unpleasant perspiration on their sides. The whole of them complain of a remarkable coldness and languor in their extremities, more especially the legs and feet, which has become habitual, denoting languid circulation in these parts, which requires to be counteracted by the application of warm flannels on going to bed. The pulse is, in many instances, more feeble, frequent, sharp, and irritable, than it ought to be, according to the natural constitution of the individuals. The sensations in the head occasionally rise to such a height, notwithstanding the most temperate regimen of life, as to require cupping, and at other times depletory remedies. Costiveness, though not a uniform, is yet a prevailing symptom.“The sameness of the above ailments, in upwards of one hundred gentlemen, at very various periods of life, and of various temperaments, indicates clearly sameness in the cause.“The temperature of the air in the Long Room ranged, in the three days of my experimental inquiry, from 62° to 64° of Fahrenheit’s scale; and in the Examiner’s Room it was about 60°, being kept somewhat lower by the occasional shutting of the hot-air valve, which is here placed under the control of the gentlemen; whereas that of the Long Room is designed to be regulated in the sunk story, by the fireman of the stove, who seems sufficiently careful to maintain an equable temperature amidst all the vicissitudes of our winter weather. Upon the 7th of January, the temperature of the openair was 50°; and on the 11th it was only 35°; yet upon both days the thermometer in the Long Room indicated the same heat, of from 62° to 64°.“The hot air discharged from the two cylindrical stove-tunnels into the Long Room was at 90° upon the 7th, and at 110° upon the 11th. This air is diluted, however, and disguised, by admixture with a column of cold air, before it is allowed to escape. The air, on the contrary, which heats the Examiner’s Room, undergoes no such mollification, and comes forth at once in an ardent blast of fully 170°; not unlike the simoom of the desert, as described by travellers. Had a similar nuisance, on the greater scale, existed in the Long Room, it could not have been endured by the merchants and other visitors on business: but the disguise of an evil is a very different thing from its removal. The direct air of the stove, as it enters the Examiner’s Room, possesses, in an eminent degree, the disagreeable smell and flavour imparted to air by the action of red-hot iron; and, in spite of every attention on the part of the fireman to sweep the stove apparatus from time to time, it carries along with it abundance of burned dusty particles.“The leading characteristic of the air in these two rooms, is its dryness and disagreeable smell. In the Long Room, upon the 11th, the air indicated, by Daniell’s hygrometer, 70 per cent. of dryness, while the external atmosphere was nearly saturated with moisture. The thermometer connected with the dark bulb of that instrument stood at 30° when dew began to be deposited upon it; while the thermometer in the air stood at 64°. In the court behind the Custom-house, the external air being at 35°, dew was deposited on the dark bulb of the hygrometer by a depression of only 3°; whereas in the Long Room, on the same day, a depression of 34° was required to produce that deposition. Air, in such a dry state, would evaporate 0·44 in. depth of water from a cistern in the course of twenty-four hours; and its influence on the cutaneous exhalents must be proportionably great.“As cast iron always contains, beside the metal itself, more or less carbon, sulphur, phosphorus, or even arsenic, it is possible that the smell of air passed over it in an incandescent state, may be owing to some of these impregnations; for a quantity of noxious effluvia, inappreciably small, is capable of affecting not only the olfactory nerves, but the pulmonary organs. I endeavoured to test the air as it issued from the valve in the Examiner’s Room, by presenting to it pieces of white paper moistened with a solution of nitrate of silver, and perceived a slight darkening to take place, as if by sulphurous fumes. White paper, moistened with sulphuretted hydrogen water, was not in the least discoloured. The faint impression on the first test paper, may be, probably, ascribed to sulphurous fumes, proceeding from the ignition of the myriads of animal and vegetable matters which constantly float in the atmosphere, as may be seen in the sunbeam admitted into a dark chamber: to this cause, likewise, the offensive smell of air, transmitted over red-hot iron, may in some measure be attributed, as well as to the hydrogen resulting from the decomposition of aqueous vapour, always present in our atmosphere in abundance; especially close to the banks of the Thames, below London Bridge.“When a column of air sweeps furiously across the burning deserts of Africa and Arabia, constituting the phenomenon called simoom by the natives, the air becomes not only very hot and dry, but highly electrical, as is evinced by lightning and thunder. Dry sands, devoid of vegetation, cannot be conceived to communicate any noxious gas or vapour to the atmosphere, like the malaria of marshes, called miasmata: it is, hence, highly probable that the blast of the simoom owes its deadly malignity, in reference to animal as well as vegetable life, simply to extreme heat, dryness, and electrical disturbance. Similar conditions, though on a smaller scale, exist in what is called the bell, or cockle, apparatus for heating the Long Room and the Examiner’s apartment in the Custom-house. It consists of a series of inverted, hollow, flattened pyramids of cast iron, with an oblong base, rather small in their dimensions, to do their work sufficiently in cold weather, when moderately heated. The inside of the pyramids is exposed to the flames of coke furnaces, which heat them frequently to incandescence, while currents of cold air are directed to their exterior surfaces by numerous sheet-iron channels. The incandescence of these pyramids, or bells, as they are vulgarly called, was proved by pieces of paper taking fire when I laid them on the summits. Again, since air becomes electrical when it is rapidly blown upon the surfaces of certain bodies, it occurred to me that the air which escapes into the Examiner’s Room might be in this predicament. It certainly excites the sensation of a cobweb playing round the head, which is well known to all who are familiar with electrical machines. To determine this point, I presented a condensing gold-leaf electrometer to the said current of hot air, and obtained faint divergence with negative electricity. The electricity must be impaired in its tension, however, in consequence of the air escaping through an iron grating, and striking against the flat iron valves, both of which tend to restore the electric equilibrium. The air blast, moreover, by being diffused round the glass of thecondenser apparatus, would somewhat mask the appearances. Were it worth while, an apparatus might be readily constructed for determining this point, without any such sources of fallacy. The influence of an atmosphere charged with electricity in exciting headache and confusion of thought in many persons, is universally known.“The fetid burned odour of the stove air, and its excessive avidity for moisture, are of themselves, however, sufficient causes of the general indisposition produced among the gentlemen who are permanently exposed to it in the discharge of their public duties.“From there being nearly a vacuum, as to aqueous vapour, in the said air, while there is nearly a plenum in the external atmosphere round about the Custom-house, the vicissitudes of feeling in those who have occasion to go out and in frequently, must be highly detrimental to health. The permanent action of an artificial desiccated air on the animal economy may be stated as follows:—“The living body is continually emitting a transpirable matter, the quantity of which, in a grown up man, will depend partly on the activity of the cutaneous exhalents, and partly on the relative dryness or moisture of the circumambient medium. Its average amount, in common circumstances, has been estimated at 20 ounces in twenty-four hours.“When plunged in a very dry air, the insensible perspiration will be increased; and, as it is a true evaporation or gasefaction, it will generate cold proportionably to its amount. Those parts of the body which are most insulated in the air, and furthest from the heart, such as the extremities, will feel this refrigerating influence most powerfully. Hence the coldness of the hands and feet, so generally felt by the inmates of the apartment, though its temperature be at or above 60°. The brain, being screened by the skull from this evaporating influence, will remain relatively hot, and will get surcharged, besides, with the fluids which are repelled from the extremities by the condensation, or contraction, of the blood-vessels, caused by cold. Hence the affections of the head, such as tension, and its dangerous consequences. If sensible perspiration happen, from debility, to break forth from a system previously relaxed, and plunged into dry air, so attractive of vapour, it will be of the kind called a cold clammy sweat on the sides and back, as experienced by many inmates of the Long Room.“Such, in my humble apprehension, is a rationale of the phenomena observed at the Custom-house. Similar effects have resulted from hot-air stoves of a similar kind in many other situations.“After the most mature physical and medical investigation, I am of opinion that the circumstances above specified cannot act permanently upon human beings, without impairing their constitutions, and reducing the value of their lives. The Directors of the Customs Fund are therefore justified in their apprehensions, ‘that the mode of heating the Long Room is injurious to the health of persons employed therein, and that it must unduly shorten the duration of life.’“It may be admitted, as a general principle, that the comfort of sedentary individuals, occupying large apartments during the winter months, cannot be adequately secured by the mere influx of hot air from separate stove-rooms: it requires the genial influence of radiating surfaces in the apartments themselves, such as of open fires, of pipes, or other vessels filled with hot water or steam. The clothing of our bodies, exposed to such radiation in a pure, fresh, somewhat cool and bracing air, absorbs a much more agreeable warmth than it could acquire by being merely immersed in an atmosphere heated even to 62° Fahr., like that of the Long Room. In the former predicament, the lungs are supplied with a relatively dense air, say at 52° Fahr.; while the external surface of the body or the clothing is maintained at, perhaps, 70° or 75°. This distinctive circumstance has not, I believe, been hitherto duly considered by the stove doctors, each intent on puffing his own pecuniary interest; but it is obviously one of great importance, and which the English people would do well to keep in view; because it is owing to our domestic apartments being heated by open fires, and our factories by steam pipes, that the health of our population, and the expectation of life among all orders in this country, are so much better than in France and Germany, where hot-air stoves, neither agreeable nor inoffensive, and in endless variety of form, are generally employed.“In conclusion, I take leave to state to you my firm conviction that the only method of warming your Long Room and subsidiary apartments, combining salubrity, safety, and economy, with convenience in erection and durable comfort in use, is by a series of steam pipes laid along the floor, at the line of the desk partitions, in suitable lengths, with small arched junction-pipes rising over the several doorways, to keep the passages clear, and at the same time to allow a free expansion and contraction in the pipes, thereby providing for the permanent soundness of the joints.”It would not be difficult to construct a stove or stove-grate which should combine economy and comfort of warming an apartment, with briskness of combustion and durability of the fire, without any noxious deflux of carbonic acid. SeeChimney.

I have recently performed some careful experiments upon this subject, and find that when the fuel is burning so slowly in the stove as not to heat the iron surface above the 250th or 300th degree of Fahr., there is a constant deflux of carbonic acid gas from the ash-pit into the room. This noxious emanation is most easily evinced by applying the beak of a matrass, containing a little Goulard’s extract (solution of subacetate of lead), to a round hole in the door of the ash-pit of a stove in this languid state of combustion. In a few seconds the liquid will become milky, by the reception of carbonic acid gas. I shall be happy to afford ocular demonstration of this fact to any incredulous votary of the pseudo-economical, anti-ventilation, stoves now so much in vogue. There is no mode in which the health and life of a person can be placed in more insidious jeopardy, than by sitting in a room with its chimney closed up with such a choke-damp-vomiting stove.

That fuel may be consumed by an obscure species of combustion, with the emission of very little heat, was clearly shown in Sir H. Davy’sResearches on Flame. “The facts detailed on insensible combustion,” says he, “explain why so much more heat is obtained from fuel when it is burned quickly, than slowly; and they show that, in all cases, the temperature of the acting bodies should be kept as high as possible; not only because the general increment of heat is greater, but likewise because those combinations are prevented, which, at lower temperatures, take place without any considerable production of heat. These facts likewise indicate the source of the great error into which experimenters have fallen, in estimating the heat given out in the combustion of charcoal; and they indicate methods by which the temperature may be increased, and the limits to certain methods.” These conclusions are placed in a strong practical light by the following simple experiments:—I set upon the top orifice of a small cylindrical stove, a hemispherical copper pan, containing six pounds of water, at 60° F., and burned briskly under it 31⁄2pounds of coke in an hour; at the end of which time, 41⁄2pounds of water were boiled off. On burning the same weight of cokeslowlyin the same furnace, surmounted by the same pan, in the course of 12 hours, little more than one-half the quantity of water was exhaled. Yet, in the first case, the aerial products of combustion swept so rapidly over the bottom of the pan, as to communicate to it not more than one-fourth of the effective heat which might have been obtained by one of the plans described in the articleEvaporation; while, in the second case, these products moved at least 12 times more slowly across the bottom of the pan, and ought therefore to have been so much the more effective in evaporation, had they possessed the same power or quantity of heat.

Stove

Stoves, when properly constructed, may be employed both safely and advantageously to heat entrance-halls upon the ground story of a house; but care should be taken not to vitiate the air by passing it over ignited surfaces, as is the case with most of the patent stoves now foisted upon the public.Fig.1073.exhibits a vertical section of a stove which has been recommended for power and economy; but it is highly objectionable, as being apt to scorch the air. The flame of the fireA, circulates round the horizontal pipes of cast iron,b b,c c,d d,e e, which receive the external air at the orificeb, and conduct it up through the series, till it issues highly heated atK,L, and may be thence conducted wherever it is wanted. The smoke escapes through the chimneyB. This stove has evidently two prominent faults; first, it heats the air-pipes very unequally,and the undermost far too much; secondly, the air, by the time it has ascended through the zigzag range to the pipee e, will be nearly of the same temperature with it, and will therefore abstract none of its heat. Thus the upper pipes, if there be several in the range, will be quite inoperative, wasting their warmth upon the sooty air.

Improved stove

Fig.1074.exhibits a transverse vertical section of a far more economical and powerful stove, in which the above evils are avoided. The products of combustion of the fireA, rise up between two brick walls, so as to play upon the bed of tilesB, where, after communicating a moderate heat to the series of slanting pipes whose areas are represented by the small circlesa,a, they turn to the right and left, and circulate round the successive rows of pipesb b,c c,d d,e e, and finally escape at the bottom by the fluesg,g, pursuing a somewhat similar path to that of the burned air among a bench of gas-light retorts. It is known, that two-thirds of the fuel have been saved in the gas-works by this distribution of the furnace. For the purpose of heating apartments, the great object is to supply a vast body of genial air; and, therefore, merely such a moderate fire should be kept up inA, as will suffice to warm all the pipes pretty equably to the temperature of 220° Fahr.; and, indeed, as they are laid with a slight slope, are open to the air at their under ends, and terminate at the upper in a common main pipe or tunnel, they can hardly be rendered very hot by any intemperance of firing. I can safely recommend this stove to my readers. If the tubes be made of stoneware, its construction will cost very little; and they may be made of any size, and multiplied so as to carry off the whole effective heat of the fuel, leaving merely so much of it in the burned air, as to waft it fairly up the chimney.

I shall conclude this article by a short extract of a paper which was read before the Royal Society, on the 16th of June, 1836,upon warming and ventilating apartments; a subject to which my mind had been particularly turned at that time, by the Directors of the Customs Fund of Life Assurance, on account of the very general state of indisposition and disease prevailing among those of their officers (nearly 100 in number) engaged on duty in the Long Room of the Custom House, London.

“The symptoms of disorder experienced by the several gentlemen (about twenty in number), whom I examined, out of a great many who were indisposed, were of a very uniform character. The following is the result of my researches:—

“A sense of tension or fulness of the head, with occasional flushings of the countenance, throbbing of the temples, and vertigo, followed, not unfrequently, with a confusion of ideas, very disagreeable to officers occupied with important and sometimes intricate calculations. A few are affected with unpleasant perspiration on their sides. The whole of them complain of a remarkable coldness and languor in their extremities, more especially the legs and feet, which has become habitual, denoting languid circulation in these parts, which requires to be counteracted by the application of warm flannels on going to bed. The pulse is, in many instances, more feeble, frequent, sharp, and irritable, than it ought to be, according to the natural constitution of the individuals. The sensations in the head occasionally rise to such a height, notwithstanding the most temperate regimen of life, as to require cupping, and at other times depletory remedies. Costiveness, though not a uniform, is yet a prevailing symptom.

“The sameness of the above ailments, in upwards of one hundred gentlemen, at very various periods of life, and of various temperaments, indicates clearly sameness in the cause.

“The temperature of the air in the Long Room ranged, in the three days of my experimental inquiry, from 62° to 64° of Fahrenheit’s scale; and in the Examiner’s Room it was about 60°, being kept somewhat lower by the occasional shutting of the hot-air valve, which is here placed under the control of the gentlemen; whereas that of the Long Room is designed to be regulated in the sunk story, by the fireman of the stove, who seems sufficiently careful to maintain an equable temperature amidst all the vicissitudes of our winter weather. Upon the 7th of January, the temperature of the openair was 50°; and on the 11th it was only 35°; yet upon both days the thermometer in the Long Room indicated the same heat, of from 62° to 64°.

“The hot air discharged from the two cylindrical stove-tunnels into the Long Room was at 90° upon the 7th, and at 110° upon the 11th. This air is diluted, however, and disguised, by admixture with a column of cold air, before it is allowed to escape. The air, on the contrary, which heats the Examiner’s Room, undergoes no such mollification, and comes forth at once in an ardent blast of fully 170°; not unlike the simoom of the desert, as described by travellers. Had a similar nuisance, on the greater scale, existed in the Long Room, it could not have been endured by the merchants and other visitors on business: but the disguise of an evil is a very different thing from its removal. The direct air of the stove, as it enters the Examiner’s Room, possesses, in an eminent degree, the disagreeable smell and flavour imparted to air by the action of red-hot iron; and, in spite of every attention on the part of the fireman to sweep the stove apparatus from time to time, it carries along with it abundance of burned dusty particles.

“The leading characteristic of the air in these two rooms, is its dryness and disagreeable smell. In the Long Room, upon the 11th, the air indicated, by Daniell’s hygrometer, 70 per cent. of dryness, while the external atmosphere was nearly saturated with moisture. The thermometer connected with the dark bulb of that instrument stood at 30° when dew began to be deposited upon it; while the thermometer in the air stood at 64°. In the court behind the Custom-house, the external air being at 35°, dew was deposited on the dark bulb of the hygrometer by a depression of only 3°; whereas in the Long Room, on the same day, a depression of 34° was required to produce that deposition. Air, in such a dry state, would evaporate 0·44 in. depth of water from a cistern in the course of twenty-four hours; and its influence on the cutaneous exhalents must be proportionably great.

“As cast iron always contains, beside the metal itself, more or less carbon, sulphur, phosphorus, or even arsenic, it is possible that the smell of air passed over it in an incandescent state, may be owing to some of these impregnations; for a quantity of noxious effluvia, inappreciably small, is capable of affecting not only the olfactory nerves, but the pulmonary organs. I endeavoured to test the air as it issued from the valve in the Examiner’s Room, by presenting to it pieces of white paper moistened with a solution of nitrate of silver, and perceived a slight darkening to take place, as if by sulphurous fumes. White paper, moistened with sulphuretted hydrogen water, was not in the least discoloured. The faint impression on the first test paper, may be, probably, ascribed to sulphurous fumes, proceeding from the ignition of the myriads of animal and vegetable matters which constantly float in the atmosphere, as may be seen in the sunbeam admitted into a dark chamber: to this cause, likewise, the offensive smell of air, transmitted over red-hot iron, may in some measure be attributed, as well as to the hydrogen resulting from the decomposition of aqueous vapour, always present in our atmosphere in abundance; especially close to the banks of the Thames, below London Bridge.

“When a column of air sweeps furiously across the burning deserts of Africa and Arabia, constituting the phenomenon called simoom by the natives, the air becomes not only very hot and dry, but highly electrical, as is evinced by lightning and thunder. Dry sands, devoid of vegetation, cannot be conceived to communicate any noxious gas or vapour to the atmosphere, like the malaria of marshes, called miasmata: it is, hence, highly probable that the blast of the simoom owes its deadly malignity, in reference to animal as well as vegetable life, simply to extreme heat, dryness, and electrical disturbance. Similar conditions, though on a smaller scale, exist in what is called the bell, or cockle, apparatus for heating the Long Room and the Examiner’s apartment in the Custom-house. It consists of a series of inverted, hollow, flattened pyramids of cast iron, with an oblong base, rather small in their dimensions, to do their work sufficiently in cold weather, when moderately heated. The inside of the pyramids is exposed to the flames of coke furnaces, which heat them frequently to incandescence, while currents of cold air are directed to their exterior surfaces by numerous sheet-iron channels. The incandescence of these pyramids, or bells, as they are vulgarly called, was proved by pieces of paper taking fire when I laid them on the summits. Again, since air becomes electrical when it is rapidly blown upon the surfaces of certain bodies, it occurred to me that the air which escapes into the Examiner’s Room might be in this predicament. It certainly excites the sensation of a cobweb playing round the head, which is well known to all who are familiar with electrical machines. To determine this point, I presented a condensing gold-leaf electrometer to the said current of hot air, and obtained faint divergence with negative electricity. The electricity must be impaired in its tension, however, in consequence of the air escaping through an iron grating, and striking against the flat iron valves, both of which tend to restore the electric equilibrium. The air blast, moreover, by being diffused round the glass of thecondenser apparatus, would somewhat mask the appearances. Were it worth while, an apparatus might be readily constructed for determining this point, without any such sources of fallacy. The influence of an atmosphere charged with electricity in exciting headache and confusion of thought in many persons, is universally known.

“The fetid burned odour of the stove air, and its excessive avidity for moisture, are of themselves, however, sufficient causes of the general indisposition produced among the gentlemen who are permanently exposed to it in the discharge of their public duties.

“From there being nearly a vacuum, as to aqueous vapour, in the said air, while there is nearly a plenum in the external atmosphere round about the Custom-house, the vicissitudes of feeling in those who have occasion to go out and in frequently, must be highly detrimental to health. The permanent action of an artificial desiccated air on the animal economy may be stated as follows:—

“The living body is continually emitting a transpirable matter, the quantity of which, in a grown up man, will depend partly on the activity of the cutaneous exhalents, and partly on the relative dryness or moisture of the circumambient medium. Its average amount, in common circumstances, has been estimated at 20 ounces in twenty-four hours.

“When plunged in a very dry air, the insensible perspiration will be increased; and, as it is a true evaporation or gasefaction, it will generate cold proportionably to its amount. Those parts of the body which are most insulated in the air, and furthest from the heart, such as the extremities, will feel this refrigerating influence most powerfully. Hence the coldness of the hands and feet, so generally felt by the inmates of the apartment, though its temperature be at or above 60°. The brain, being screened by the skull from this evaporating influence, will remain relatively hot, and will get surcharged, besides, with the fluids which are repelled from the extremities by the condensation, or contraction, of the blood-vessels, caused by cold. Hence the affections of the head, such as tension, and its dangerous consequences. If sensible perspiration happen, from debility, to break forth from a system previously relaxed, and plunged into dry air, so attractive of vapour, it will be of the kind called a cold clammy sweat on the sides and back, as experienced by many inmates of the Long Room.

“Such, in my humble apprehension, is a rationale of the phenomena observed at the Custom-house. Similar effects have resulted from hot-air stoves of a similar kind in many other situations.

“After the most mature physical and medical investigation, I am of opinion that the circumstances above specified cannot act permanently upon human beings, without impairing their constitutions, and reducing the value of their lives. The Directors of the Customs Fund are therefore justified in their apprehensions, ‘that the mode of heating the Long Room is injurious to the health of persons employed therein, and that it must unduly shorten the duration of life.’

“It may be admitted, as a general principle, that the comfort of sedentary individuals, occupying large apartments during the winter months, cannot be adequately secured by the mere influx of hot air from separate stove-rooms: it requires the genial influence of radiating surfaces in the apartments themselves, such as of open fires, of pipes, or other vessels filled with hot water or steam. The clothing of our bodies, exposed to such radiation in a pure, fresh, somewhat cool and bracing air, absorbs a much more agreeable warmth than it could acquire by being merely immersed in an atmosphere heated even to 62° Fahr., like that of the Long Room. In the former predicament, the lungs are supplied with a relatively dense air, say at 52° Fahr.; while the external surface of the body or the clothing is maintained at, perhaps, 70° or 75°. This distinctive circumstance has not, I believe, been hitherto duly considered by the stove doctors, each intent on puffing his own pecuniary interest; but it is obviously one of great importance, and which the English people would do well to keep in view; because it is owing to our domestic apartments being heated by open fires, and our factories by steam pipes, that the health of our population, and the expectation of life among all orders in this country, are so much better than in France and Germany, where hot-air stoves, neither agreeable nor inoffensive, and in endless variety of form, are generally employed.

“In conclusion, I take leave to state to you my firm conviction that the only method of warming your Long Room and subsidiary apartments, combining salubrity, safety, and economy, with convenience in erection and durable comfort in use, is by a series of steam pipes laid along the floor, at the line of the desk partitions, in suitable lengths, with small arched junction-pipes rising over the several doorways, to keep the passages clear, and at the same time to allow a free expansion and contraction in the pipes, thereby providing for the permanent soundness of the joints.”

It would not be difficult to construct a stove or stove-grate which should combine economy and comfort of warming an apartment, with briskness of combustion and durability of the fire, without any noxious deflux of carbonic acid. SeeChimney.

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