the stem of the skimmer which is lowered to take up the ore, it then passes through the stem into any receptacle placed to receive it. Another arrangement or modification of this machine is thus :-within a similar tank is firmly fixed a sieve, having a hollow shaft or spindle penetrating its centre, and after passing below the sieve branches off to a receptacle in a similar position to the other; a concentric compartment is formed around the shaft where it passes through the sieve, also a skimmer, the mouth of the same formation as the one hereinbefore described, having its stem curved and bent downwards into this central compartment. Within the exterior of this central compartment and the annular margin of the sieve, the mouth of the skimmer revolves, motion being imparted to it by means of wheels, &c., in an ordinary way, to the upright shaft, to which the skimmer is fixed. In this arrangement, the raising and separating the ore or mineral is produced by the sole force of the impulsions upwards, given by the force-pump, which is the same in both arrangements. When the machine is in action, it will be easily seen that a corresponding effect is produced in both apparatus; in this, the skimmer traverses the ore at a regulated depth from the surface, and the waste is carried by the rotative force and the stream of water into the skimmer, and from thence into the central compartment, from whence it passes down the hollow shaft into the receptacle appointed to receive it; in the former apparatus the skimmer is fixed, and the sieve revolves. The second part of the invention relates to a method of dressing small ore and sleines of ore. A hollow frame or trunk, having for its section the exterior form of a cone, which converges to its centre from the extremes of its base, and terminates in an aperture having a cock. To this entre is fixed an iron arm or step, upon which the whole apparatus revolves. The apex is formed like a goblet, for the purpose of a funnel, into which the small ores or sleines of ore are poured. On each side or limb of this trunk or hollow frame are attached three receptacles, the first, opening from the trunk into the uppermost one, being about one-third from the apex or funnel; the second, communicating with the middle one, at about two-thirds from the said apex; and the third, at the angle or extremities of the base. A pulley is fixed to the under side of the funnel, by which a rotative motion is imparted to the whole of the hollow frame or trunk, and the small ore

or sleines of ore in a moistened state are poured into the funnel, and passing down the hollow trunk, the centrifugal force, which is generated by the revolving of the trunk, causes the heaviest of the ores to be discharged at the upper opening into the adjoining receptacle; the next less in size into the middle one, and the least, or sleines, into the lower one; the water which passes into the trunk with the small ore or sleines of ore, is discharged by means of the cock at the base, immediately above the step upon which the whole revolves. When the receptacles are full, the small doors in front of each are removed, and the ores taken out and placed in the usual bins, according to their various sizes. The patentee having described the nature of his invention, and the manner in which he carries out the same, states his claims as follows, viz:-First, the conveying the ores and waste into another receptacle over the annular margin of the sieve, by means of a skimmer-pipe and stream of water. Secondly, the application of the force-pump, by the impulsions upwards of which the particles are enabled to adjust themselves in perfect stillness of the water during the intervals of the same, together with the means of regulating the descending stream of water as may be necessary; and Thirdly, the application of a centrifugal force for producing an artificial gravitation, and the means herein described whereby it is made subservient to separating ores and minerals. WILLIAM EDWARD NEWTON, of ChanceryLane, for improvements in the mode or modes of manufacturing or preparing certain matters to be employed as pigments. Patent dated November 16th, 1847. Enrolled May 16th, 1848. (Communication.)

THE object of the present invention is the manufacture and mode of collecting various matters suitable to be employed as pigments, and the matters which it is proposed to manufacture or prepare for the above purpose, are the following:zinc white, zinc yellow, and zinc green. First, with reference to the manufacture of zinc white and the method of collecting the products:-Zinc white can be obtained commercially by distilling the metal from the mineral, or from the oxide, by means of the arrangement of furnaces hereafter described, which consists of a common glass furnace with certain modifications, and the additional appendages necessary for manufacturing and collecting zinc white. A number of retorts made of re

fractory clay or other suitable material are introduced on each side of the furnace, and are capable of resisting a high temperature. The number of retorts represented are five, but this may be varied either by increasing or diminishing; they have each openings or mouths, whereby the products of distillation escape therefrom. Rods or bars of iron are suspended from above, and are adapted to the openings or mouths of the retorts in such manner that, by causing them to move laterally in front thereof, they may scrape off any adherent matter from the front caused by the products of distillation, which would otherwise obstruct the opening. A horizontal bar is attached to all these scrapers, by moving which they will all be made to act simultaneously, and may either be worked by hand or by any suitable mechanical means. Hoppers for receiving the heavy masses of calcined zinc are disposed in such a manner below the openings or mouths of the retorts, that their lower ends may, by means of short pipes, terminate in a general or common channel, and from thence the product is carried down into a recipient. It should be understood that these channels are only intended to receive the solid matters which escape during distillation, or that portion of the product that accumulates near the orifice or mouth of the retort, and is too heavy a body to be drawn by exhaustion towards the oxidizing chamber. A small iron chamber is applied to the mouth of each retort for the purpose of isolating them from one another. It is placed upon a framing, and is fixed to the wall, but it may be so arranged as to admit of being removed at pleasure by any suitable contrivance. The front part of these chambers is open, and is placed opposite the orifice or mouth of the retorts, so that the products of distillation may issue from the retorts, and the back part may be made to open or shut at pleasure. A trap or opening is made in the floor immediately below the small coveringchambers; this trap is hinged at one end, and may be raised and lowered by means of an iron chain or rod, passed across the back part of the chamber, so that the trap is raised or lowered without the necessity of opening the chamber; this, however, may be accomplished by a trap sliding in grooves horizontally. The above-mentioned arrangements may be adapted to furnaces for treating zinc in which a certain part of the oxide that is formed is always lost, and which might be collected either by the above-described method or by closing by means of a cloth

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this

the space situated beneath the vessel where they will be deposited. If the iron chamber is employed, a small opening may be made in the front, which may be opened and closed at pleasure, and a glass may be placed therein in order to enable the attendant to watch the operations that go on in the chamber, and the manner in which the distillation proceeds. In place of the constructions and arrangements above mentioned, the same object may be effected by fixing a vertical plate on each side of the mouth of the retort, and adapting a third plate, which should serve as a cover to be raised and lowered at will. The flooring before mentioned, immediately under the chambers which cover the openings of the retorts, separates this part of the apparatus from the oxidizing chamber; currents of cold air may be directed either into the chamber above the floor, and in which the retorts are worked, or into the floor itself, which is made hollow for the purpose, so that by a continual current of cold air passing through the floor, the temperature of the chamber may be kept down, and rendered supportable. A pipe for supplying hot air communicates with the pipes of the hoppers before mentioned, from which it drives out the white product and sends it into the oxidizing chamber; chamber is placed immediately below the retort floor, and is called the oxidizing chamber, because the metallic vapour is there oxidized upon leaving the retort by its contact with the atmospheric air. The lower part of this chamber terminates in a hopper or inclined plane, in which are arranged cloths or woven fabrics for sifting the products which become deposited, and slide down by their own weight into receptacles placed in a chamber below; these hoppers are furnished with valves, cocks, or registers, for the purpose of opening or closing the passage of the products. The whole of the products may be collected without loss by means of suitable iron pans or receivers filled with water and furnished with two pipes, one for communicating with the oxidizing chamber in which the zinc white is produced, and the other end is inserted in the water of the vessel, and conducts the zinc white thereto from the oxidizing chamber, and the end of the other pipe does not enter the water, but, by withdrawing air from the vessel, a vacuum is produced in the first pipe which enters the water, and the products are drawn down and deposited therein. The woven fabries are placed in a vertical position in the oxidizing chamber at

suitable distances apart, for the purpose of allowing the passage of the atmospheric air, and of retaining and sifting the products, which is effected by means of an exhaust chamber; it may also be effected by means of force-pump fanners, or other blowing apparatus. Another pipe is placed above the mouths of the retorts; it is furnished with a funnel-shaped mouth, through which the volatilized products that escape from the retorts are drawn while the retorts are being charged, and their ordinary communication through the trap with the oxidizing chamber is cut off, the trap thereto being down. This last-mentioned tube conducts the volati. lized products by another channel to the oxidizing chamber and sifting partitions; or they may be made to pass through other sifting partitions arranged expressly for the purpose in connection with this pipe, which is closed whilst the retorts are in operation. The preceding arrangements have for their principal object the separation of the retorts from each other, and it will be understood that this object may be attained by other analogous means for instance, the flooring might be so arranged as to be capable of being raised and lowered at pleasure, so as to separate the retorts from one another if requisite. It might also be divided into sections corresponding to the number of retorts, so that the part only of the floor which is required to be insulated from or put in communication with the oxidizing chamber, may also be raised or lowered. A blast furnace is represented as adapted for this purpose, which must be closed at top, either by a cover, which may be moveable for the purpose of charging, or by a hopper, in which the substances to be operated upon may be placed; or it might be hermetically closed at top, and open at one side for the purpose of charging, which opening must be closed after charging, or the substances may be supplied through the opening near the top where the product escapes to the oxidizing chamber; this must be arranged with an inclined plane, upon which the substances to be supplied to the furnace are to be poured. A reverberatory furnace, or a furnace similar to those employed for making coke, might be adapted to the above purpose, but these being so well known, it will be unnecessary to enter into any detailed description of them; he, however, observes that in making use of these latter, the bed must be heated either by means of a fire-place situated in front, the flame from which passes under the bed, and

an

through flues round the furnace, making its exit through a chimney above, or it may be heated by a fire-place underneath. These furnaces are provided with opening at the top or side for the passage of the products into the collecting chamber as before mentioned. A furnace, which he describes as being of novel construction for the manufacture of zinc white, is represented in the specification; it consists of two long horizontal tubes set side by side, in which fire-places carried below such tubes are constructed at convenient distances, and fed with blasts of air. These tubes are constructed of firebricks or other substances capable of resisting a considerable degree of heat. Flues through which air (either hot or cold) may be driven by means of a blower are introduced at each side of the furnaces in the lowest part of which the residual matters of combustion accumulate, and may be removed from time to time, or this part might be prolonged immediately under each fire-place so as to form a kind of ash-pit, and the ashes removed through an opening made for that purpose; the bottom part of the fire-place being closed by fire bars or by a register which might be opened at will to allow the ashes to fall into the space beneath, or instead of a register it might be closed by a grating of such a size as to retain the ore and allow the scoria only to escape through the bars into the ash-pit; by this arrangement a current of air might be conducted up through the bars and the blowing machine might thus be dispensed with. It is desirable to mix some appropriate flux with the matters when introduced into the fur. nace in order to reduce the scoria to a liquid state and then to run it through an opening made at the lower part of the fireplace. The tubes or chambers before mentioned are merely cylindrical hollows formed in the mass of brick-work composing the furnace; they have openings at each end, and current of air is drawn through the tube for the purpose of conducting the volatile products to the collecting chamber, and of oxidizing the metallic vapours which are evolved during combustion. The oxidizing chamber is of a similar construction as that already described, and is also furnished with a wiregauze or other woven fabric for the purposes of sifting. In order to charge these furnaces, openings or doors are made in the upper side of the tubes immediately above the fire-places; these openings are furnished with a hopper or hoppers into which a charge is put, and by withdrawing a slide at the bottom the charge is

suffered to descend into the fire-place below when the slide is directly replaced. What is claimed under this invention is: First, the distillation of metallic zinc, of oxide of zinc, or zinc ore, by one of the means above mentioned. Second, the application of furnaces similar to glass furnaces and coke ovens as above described, and the modification of them respectively in order to fit them for the purpose of manufacturing zinc white. Third, the novel construction of furnace described as being formed of two cylindrical tubes placed side by side with furnaces or fire-places formed in the lower part of the brick work. Fourth the isolating the retorts from each other and also cutting off the communication between the retorts and the oxidizing chamber when required, whatever means may be employed to effect that object, not confining himself to the apparatus shown for that purpose. Fifth, the employment of suitable apparatus for cleansing the mouths of the retorts without being obliged to enter the oxidizing chamber. Sixth, the arrangement of apparatus by which the retorts may be charged, cleansed, and replaced, or submitted to any operation required without interfering with the oxidizing chamber. Seventh, the application or employment of blast-furnaces for the production or manufacture of zinc-white or oxide of zinc, whether such furnaces are circular or of any other suitable form, and whether they are constructed and arranged in a vertical, inclined, or horizontal position. Eighth, the employment or introduction of currents of air into an oxidizing or other chamber, for the purpose of converting the metallic vapours of zinc into zinc-white or oxide of zinc; also the employment of an exhaustion-tube or blowing-apparatus for conducting the metallic vapours to the oxidizing chamber as above described. He claims also the employment of wire-gauze or sieves for sifting the products; also the arrangement of vessels for receiving the heaviest portions of products. Ninth, the arrangement of the oxidizing chambers so as to allow the products being collected from the said chambers without the necessity of entering them. Having described all that appertains to the manufacture and manner of collecting zinc-white, he next proceeds to an expla nation of that part of the invention which relates to the other colours, viz., yellow of zinc and green zinc. Zinc yellow.-As the manufacture of this forms the subject of a previous patent, he merely remarks that hydrochloric acid may be used instead of sulphuric acid. Zinc green yellow having

been produced by the patented process, is diluted with a suitable quantity of water, and mixed with a certain quantity of prussian blue (previously mixed with a suitable quantity of water, oil, or other appropriate liquid) either in a hot or a cold state; green of zinc will thus be formed, the colour of which will be as durable as the blue itself. The above substances may be employed for painting of any kind, or for any other purposes for which white lead or other pigments are employed.

HENRY KREBS CLAYPOLE, of Liverpool, gentleman, for certain improvements in the process, apparatus, and machinery for making sugar. Patent dated November 9th, 1847. Enrolled May 9th, 1848. -(Communication.)

THIS invention consists of certain new, and improved arrangements of machinery, and of an improved process for making sugar after the juice has been extracted from the cane. The improvements apply chiefly to the boiling, clarifying, and crystallizing of sugar, the employing of various improved portions of machinery, and the obtaining sugar, by the process herein described, in larger quantities and of superior quality, thereby effecting a great saving of fuel, labour, and time. The patentee, after describing the system generally adopted and its defects, says it was incumbent upon him to take care and place the improvements within the reach of every planter, by rendering still available the old plant, machinery, and apparatus now in use, without any great additional expense. The improvements hereinafter described are applicable only to the treatment of the saccharine juice when extracted from the cane. The first part of the invention relates to an improvement in the machinery for cooking cane juice, with a less consumption of fuel, and doing without the steam-furnace (excepting for a short time at the commencement of the grinding), and until the teache and boilers are supplied with juice to permit the fire under the same to be lighted. Between the furnace chimney and the boilers, two generators are fixed vertically, each being provided with iron tubes in the interior, the number of which and the size of the generators vary according to the power of the engine. In front of the teache is the furnace, which is supplied with baggass for fuel. The flame from this fire-place passes underneath the teache and boilers; bridges, or projections being constructed between each upon the bottom of the flue

to turn the body of flame directly against the bottom of the boilers. It will be perceived that this flame, which is not. entirely exhausted after having passed under them, will still contain a great amount of caloric, sufficient to heat the generators, and thereby produce a sufficiency of steam necessary for the supply of the engine of the cane-mill. Thus

the same fire will serve for the process of cooking sugar and the generating steam for the engine. These generators are furnished at top with a receiver, into which the steam is collected; above this rise two small sheet-iron chimneys, one over each generator. Two small pipes enter these chimneys at the lower part, furnished with a cock at the centre, for the purpose of admitting steam into them. The second part of the invention consists in improvements relating to the increasing of the draught in the sugar furnace. This result is obtained by means of the two small sheet-iron chimneys. Into these chimneys a small quantity of high-pressure steam is injected by means of the pipe connected with the receiver; this current of steam entering at the bottom of the chimneys, carries up in its ascent the atmospheric air to the top, and produces a strong vacuum in the furnace in a similar way to locomotives, excepting that the steam employed here is new, and not exhausted steam, which exerts a back pressure upon the piston. The result of this contrivance increases the draught in the sugar furnace to such an extent as to produce the combustion of all the gases contained in the baggass. The third part of the invention refers to the progress of the clarification of cane juice. The clarifiers are made with a double bottom, into which the exhausted steam is admitted. They are also provided with an iron tube of five inches in diameter, the shape of the clarifier bottom, into one end of which the steam is admitted; at the opposite end is a small branch for carrying off any water that may form therein, from the condensation of the steam. The bottom of the clarifier is fitted with a gaugecock (in the centre), for removing the juice when clarified. Into this tube a small quantity of high-pressure steam is introduced, and by this simple process the heat of the juice is properly increased to the required temperature of 212° Fah., with the rapidity necessary to insure a safe and good defecation. The fourth part of the invention relates to the teache, which is of cast-iron, and of the form of those usually employed for finishing the

operation of cooking sugar. The bottom is provided with a canal or passage, which terminates in a mouth closed by a valve, acted upon by a lever, having a weight at the end, which, pressing the lower edge of the valve against the face of the mouth or opening of the canal, closes the aperture of the canal. When the operation of cooking is performed, and the sugar has arrived at the proper point, the valve is raised by lifting up the lever and weight, and the sugar runs out of the teache into the coolers. The fifth part of this invention refers to the crystallization of sugar. Coolers or crystallizers, made of galvanized sheet iron, are used, being furnished with handles so that they may be lifted about; they are extremely portable, and are not intended to contain more than 50 lbs. of sugar each. When the matter to be crystallized (having attained in the teache the proper point of cooking) is drawn off into the coolers, the evaporation of the heat takes place very rapidly, owing to the galvanized iron being a quick conductor of caloric. The crystallization of the sugar is complete in six hours, and is then ready to put into the hogsheads. The result of this improvement is that the grain of the sugar is of a superior quality, and at the same time a saving of 25 per cent. of molasses is effected. Having now described the nature of the invention, and the manner of performing and carrying out the same, the patentee observes that he does not claim for the invention the several parts of the machinery, apparatus, or process herein described; nor does he confine himself to the exact proportions or modi operandi hereinbefore mentioned, provided their general features be the same as herein laid down; but what he claims as new and as constituting the invention communicated to him is, first, the application of two separate generators, each provided with a certain number of tubes and fixed above the sugar furnace, to the manufacture of sugar. Secondly, the use of a current of high-pressure steam in a chimney to facilitate and promote the egress of the atmospheric air at the top, and producing a perfect vacuum in a sugar furnace. Thirdly, the process of clarifying sugar by the application of an iron tube to a double-bottom clarifier, and of increasing rapidly the temperature of highpressure steam. Fourthly, the application of a canal to the teache, for the drawing off the sugar. Fifthly, the use of galvanized sheet-iron coolers, to cool the sugar in.