Patent dated November 11th, 1847. Enrolled May 12th, 1848. THIS invention relates to improvements upon a former invention patented by the present patentee, and consists of an improved apparatus for ærating liquids by means of gas generated under a pressure, and ærating the liquids by its own elastic force. The machine or apparatus formerly patented consisted of a chamber divided into two, an upper and lower, compartments by a horizontal diaphragm; the lower compartment being that in which the gas was generated, and which, by its own pressure, rushed up a series of tubes, and was dispersed through the liquid to be ærated in the upper compartment in a number of small jets, by means of a rose. The principle, then, being the same, the invention is confined to the apparatus for ærating liquids, and is represented in the annexed cut. Fig. 1, being a vertical section, and fig. 2, an external elevation of the same, complete; the container, a,a, is formed of stoneware or earthenware, of a cylindrical form, having one hemispherical end, the other being flat; the upper part is furnished with an opening, b, where the liquid to be ærated is introduced; a conical tube or chamber, c,c, is secured by means of cement to the inside of the container, a,a; this chamber, c,c, also terminates in an opening, d, at the top; about one-third from the bottom is a horizontal strainer, e, having a series of holes round the circumference, the centre being solid, as will be seen by reference to fig. 3; a small tube, f, about a quarter of an inch inside, runs up the side of the tube, c,c, the lower part opening into the chamber, g, by a number of small openings, and opening into, e, by a contracted aperture, n, of one-eighth of an inch diameter. For the purpose of a safeguard for the prevention of breakage, and also as a means of closing the openings, b, and d, he encases this apparatus in a vessel of tin plate, or other suitable metal, closely fitting; the exterior rings of metal, having screws cut thereon, are soldered to the tin casing, by means of which caps are secured to the several orifices without the trouble of cement or other means taken to render them air-tight: The cock, h, by which the ærated liquid is withdrawn, is similarly secured to the container, a, a recess being formed in the side of the earthenware for the reception of a washer of leather or other elastic substance, against which the end of the cock is pressed. As a standard size for this apparatus, he has supposed its contents to be equal to about a gallon, the container being six inches in

diameter, and sixteen inches long, inside measurement, the tube, c,c, being about three inches and a half at the bottom tapering upwards. In proceeding to ærate liquid by means of this apparatus, it is to be poured into the opening, b, nearly filling the space, g; about three quarters of a pint of water is then poured into the orifice, d, all of which will pass through the strainer, e, into the space below, which it will nearly fill, three ounces of crystallized tartaric acid, coarsely pulverized; this will rest on the solid part of the strainer: he next introduces quarter of a pound of carbonate of soda, which he drops through the same opening; this, by being also received on the strainer, is kept perfectly dry, thereby preventing any gas being generated; the cap is now secured on the aperture, d, when the apparatus is to be oscillated on the pivots, i,i, which support it in the framing. By thus agitating the contents of the vessel, some of the water contained below the strainer, e, will rush up the apertures in the strainer, mixing with the soda and acid, and causing thereby the immediate formation of carbonic-acid gas; and by continuing this agitation for some minutes will create considerable pressure in the vessel, c; the gas having no other means of escape, passes through the small orifice into the pipe, f, and thence escaping by the perforations at the bottom, passes up through the liquid to be ærated; the aperture, b, is allowed to remain open some little time, in order to admit of the escape of the air contained in the appa. ratus; the oscillation of the apparatus being continued, (care being taken that it never reaches the horizontal), the liquid contained in the chamber will become highly charged with gas, when it will be ready to be drawn off by the cock, h. Instead of the ingredients mentioned, other acids may be used, such as dilute sulphuric acid, together with the carbonate of soda, in which case it must always be in a state of dry powder. In using this apparatus, the tube, c, must be well rinsed in hot water and the gas is generated, as the previous charge would act prejudicially on the next. Having described the nature of his invention, he wishes it to be understood that he does not claim as of his own invention the generating of gas under a pressure, and by its own expansion ærating liquids; but what he claims, is, first, the arrangement of apparatus whereby carbonates used for the production of carbonic-acid gas is kept dry or nearly so during the action of the acid or acids, thereby pre

venting any violent ebullition. Secondly, the method of closing the orifices of the different vessels, and also the applying the cock whereby a washer or cork cap is screwed into, or on, the closing surface, so as to avoid any metallic contact with the liquid.

RICHARD LAMING, of Clichy-le-Garenne,

France, for certain improvements in manufacturing and purifying coal-gas, and in treating a residual product of such manufacture; also improvements in preparing materials to be used in the purification of coal-gas. Patent dated November 4th, 1847. Enrolled May 4th,

1848.

THE first part of this invention, which relates to improvements in the manufacture of coal-gas, consists of improvements in the construction of furnaces used for manufacturing gas, and has for its object to economise fuel, while, at the same time, the destructive heat of the fireplaces is lessened. These advantages are obtained by retaining the combustion of the uel in the firc-places, so as to convert the same into carbonic oxide gas, which is burnt into carbonic acid (atter it leaves the

fire-place) by means of air heated by the products of combustion in their way from the oven to the chimney. The patentee is aware that hot air has been heretofore used for increasing the combustion of fuel in fire-places, and also for converting carbonic oxide into carbonic acid; he does not, therefore, claim these points as constituting any part of his invention, except when effected in the manner and for the purposes set forth and described; but that which he considers to be the characteristic features of this part of his improvements, as applied to the manufacture of coal-gas, and wishes to claim, is the use of pipes made either of iron-clay or other suitable material heated in flues or chambers in which they become surrounded by the products of combustion in their way from the oven to the chimney, and conducting heated atmospheric air into the passages between the fuel and the retorts for the purpose and in the manner shewn and described. Another part of the patentee's invention is an improvement or improvements in the manner of using chloride of calcium for the purification of coal-gas. The patentee does not claim the use of that re-agent in

In

a dry state, nor when it is in a fluid condition; both those ways are attended by inconvenience: in the one case, fluids cause objectionable pressure on the retorts; and, in the other case, dry chloride of calcium desiccates the gas, and thereby causes it to deposit naphthaline. The patentee avoids both these evils by mixing the powdered chloride with sawdust or other convenient and absorbent matter, and then sprinkling the mixture with water until it becomes very damp or wet; or, which is still better, by causing a strong solution of the chloride in water to be absorbed into dry sawdust or other convenient matter, in such proportion as to confer upon the mass the form of a wet and granulated powder. The patentée claims the use of chloride of calcium, prepared in either of these ways, for the purification of coal-gas, and he uses it in the manner in common use for hydrate of lime. He claims, also, the use of muriates and sulphates of manganese, iron, and zinc, prepared by absorbing a strong solution of those salts respectively into sawdust, as explained with respect to chloride of calcium; but he does not claim the use of either of the aforesaid metallic salts in a fluid state, or in a state of mechanical division and wetted, even though they be mixed with sawdust. addition to the objectionable pressure caused by all fluids, metallic solutions in particular obstruct the purifying apparatus by letting fall heavy precipitates, and the mere mechanical division of a metallic salt, such as sulphate of iron, leaves in the centre of each fragment, however small it be, a quantity of the re-agent on which the impurities in the gas can hardly be made to act. Chloride of calcium is both abundant and cheap; under certain circumstances it may, however, be desirable to make it, for the purposes of gas purifying, by decomposing muriate of manganese, iron, or zinc, by means of lime, or of chalk when the latter will suffice. In such cases the oxides or carbonates which result are useful for the said purification, and need not be removed. He does not claim either of these processes for making a mixture of chloride of calcium and a metallic oxide or carbonate; but he does claim the application of mixtures so made to the purification of coal-gas. Another part of the invention consists in the use of the carbonates of manganese, iron, zinc, and lead, for the purification of coal-gas, for which purpose they are damped and disposed, mixed or unmixed with sawdust or other matter, in the course of the gas as is prac

tised with hydrate of lime; or the patentee mixes them with the purifying matters which he has claimed as his invention; or with other purifying matters hitherto in use for a similar purpose in a state of mechanical division. To obtain these carbonates in an economical manner, the patentee throws down from ammoni. acal or gas liquor obtained in making coal-gas, and previously distilled or not, the sulphur which it contains; and having drawn off the clear liquid, he next precipitates its carbonic acid, or instead of making two separate precipitates, he throws down a mixed sulphuret and carbonate of the precipitant or precipitants. He prefers to precipitate by means of a muriate or sulphate of manganese, iron, zinc, or lead; he does not claim either of these ways of obtaining a metallic carbonate, but he claims the use of the carbonates above named, however obtained, for the purification of coal-gas. Another part of the patentee's invention consists in certain ways of treating the ammoniacal liquor of gas works, so as to obtain from it and sulphate of lead a solution of sulphate of ammonia, and either an oxide or a carbonate of lead of sufficient purity to serve as, or to be made into, white lead; he proceeds as follows: the gas liquor is first distilled either with lime or without addition; in the former case the caustic ammonia contaminated with hydrosulphuric acid, is received in water; and in the latter case the carbonate and hydrosulphate of ammonia are received in water. In both cases the next step is to remove the whole of the hydrosulphuric acid, which the solution contains, and which he prefers to do by stirring in enough carbonate of lead, taking care that the clear liquid be afterwards perfectly separated from the sédiment; he next str in enough white sulphate of lead to furnish to the ammonia its equivalent of sulpuric acid. In the case of the caustic ammonia, the lead will be found at the bottom of the vessel as a white hydrated oxide; and in the case of the carbonated ammonia, a white carbonate of lead falls down, the solution in either case containing sulphate of ammonia. Another part of the patentee's inventión consists in increasing the purifying powers of the aforesaid preparation of chloride of calcium, or chloride of calcium and metallic oxide, or chloride of calcium and metallic carbonate, and also of the aforesaid metallic salts absorbed in solution into sawdust, by adding thereto oxide of manganese, iron, zinc, or lead, obtained in a proper state from any other economical

source. The oxide which he prefers is one or other of the oxides of manganese prepared from the carbonate of that metal by a process of which he claims the practical application. It is as follows:He exposes the carbonate to a heat gradually increased to near redness, with access of air for an hour or two, or until the carbonic acid be expelled, and oxygen absorbed in its place. If in this process the carbonate of manganese be contaminated with sulphur, or if vegetable matter be present and it ignites, or if the heat be very great and too suddenly applied, or if the molecules of carbonate be inveloped by soluble matter, then only a red or brown oxide results; but in the absence of all those impediments so much oxygen combines with the manganese as to convert it into the black or peroxide. The patentee does not claim the exclusive use of any metallic oxide for purifying coalgas, but what he does claim is the combination for that purpose of the oxide of manganese, iron, zinc, or lead, or either of them, with the other purifying matters above recited, and whereby the gas may be perfectly purified from its ammonia and all its hydrosulphuric acid without requiring a succession of purifying vessels. Another part of the patentee's invention consists in certain processes for making carbonate of manganese. First, he mixes together in solution muriate or sulphate of manganese with an equivalent quantity of gas liquor, previously distilled or not, but in either case carefully deprived by any known means of its hydrosulphuric acid; and then having withdrawn the supernatant liquid, he thoroughly washes the precipitated carbonate with water; secondly, he adds carbonate of soda to a solution of waste residue from the makers of chlorine, which consists nearly of an equivalent of sulphate of soda and an equivalent of sulphate of manganese until the latter is decomposed; he then decants the solution of two equivalents of sulphate of soda which result from the precipitated carbonate of manganese, and washes with water as before; the solution of sulphate of soda, also, is a valuable product; third, he boils carbonate of magnesia with an equivalent quantity of sulphate or muriate of manganese in solution, and having decanted the solution of sulphate or muriate of magnesia, washes the precipitated carbonate of manganese. Sometimes he replaces the carbonate of magnesia by magnesian lime-stone in powder, and thus obtains the carbonate of manganese mixed with carbonate of lime, which does not prevent its efficacious

application to the purification of coal-gasin the ways described; that is to say, either as a carbonate or converted into an oxide. Another part of the invention consists in certain economical processes for applying preparations of lead and zinc to the purification of coal-gas, and in recovering them for repeated use. He next describes his manner of proceeding with respect to lead, premising that the description will apply also to zinc; he procures a mixture of sulphate and oxide of lead in coarse powder, the exact proportions will vary with the nature of the coals from which the gas has been made, but they may be about two equivalents of the latter to one of the former. He wets this mixture and causes the gas to pass through it; after a time it ceases to purify the gas sufficiently, in consequence either of its sulphuric acid being saturated with ammonia or the oxide no longer arresting the hydrosulphuric and carbonic acids. A small quantity of acetic or nitric acid may be added to the water with which the oxide is to be wetted. The used matters being removed from the purifying vessel, are dried and exposed in a furnace or on an iron plate for an hour or two, to a low red-heat, which restores them again to the state of sulphate and oxide of lead, with the volatilization of hydrosulphate of ammonia, which may be allowed to escape; or if it be desired to save this ammonia, the heat at first should be applied to the mixture in a retort, and the volatile matter conducted into water or some acid or apparatus capable of condensing it. Or the ammonia may be saved by washing out the sulphate of ammonia from the used matters, and then exposing the insoluble residuum to heat as before stated, for its conversion into sulphate and oxide of lead. For washing out the sulphate of ammonia, he sometimes uses the gasliquors either distilled or not, which have been already converted into a solution of sulphate of ammonia by sulphate of lead, and repairs the waste of sulphate and oxide of lead in the daily operations, by adding to the used mixture before heating it, a part of the precipitated sulphuret and carbonate of lead, which results from the action of sulphate of lead on the gasliquor.

SOCIETY OF ARTS.

The thirteenth ordinary meeting of the Society of Arts took place at the Society's house on the 10th inst. Peter Le Neve Foster, Esq., F.R.S., in the chair, in the

absence of I. K. Brunel, Esq., C.E., vicepresident, in rotation.

The minutes of the preceding meeting having been read,

Mr. S. Sidney read a paper "On Mr. John Fowler's improved ferry," proposed to be constructed across the Humber, forming a portion of the Manchester, Sheffield, and Lincolnshire Railway. It will cross the river from Hull to New Holland, a small town on the Lincolnshire shore, three miles and a half below Barton. A noble terminus for carriages, &c., will be erected in the main street of Hull, abutting on the river, 1,500 feet beyond. In the stream is a stone pier; this is connected with the terminus by means of an iron tubular gallery, similar in construction to the Conway bridge; beyond the pier, and continuing towards the centre of the river, is a further gallery, similar in construction to the former, having one end resting on the pier, the other on a floating caisson, which rises and falls with the tide, being guided by means of upright piles arranged in a triangular form, and lying in the direction of the stream; the length of the larger tube is 1,500 feet and feet 25 square internally, that of the smaller tube is 200 feet long by 15 feet diameter, and weighing 240 tons; the base or footway is only sufficiently strong to carry the general intended weight; the greatest mass of metal being concentrated in the roof, which, with the aid of beams, forms a structure of extreme strength, so that it cannot give way until the fibres of the metal are actually driven one into the other; the whole being constructed of the rectangular-cellular form, the invention of Messrs. R. Stephenson, Fairbairn, and Hodgkinson. This ferry, when completed, will form one of the greatest triumphs of engineering skill to be found in the country.

The next paper read was that of Dr. Potts, "On his invention of pneumatic pile-driving," the principle of which is the formation of an attenuated atmosphere within a hollow pile, by which the water

forced up from below, breaks up the natural arches formed by the particles of the soil; and these being drawn up within the pile, it sinks with a force due to the weight of the atmosphere on the cap of the pile, and that of the pile itself.

The thanks of the meeting having been given to the authors of the respective papers, the Society adjourned.

On the 17th inst. the fourteenth meeting of the Society took place, J. Fuller, Esq. in the chair.

The second part of Dr. Potts' paper, showing its applicability to the formation of the foundations of lighthouses and beacons on the most dangerous sands, having been read, Mr. Buckwell's patent artificial granite, for architectural and engineering purposes, was the next subject; specimens were exhibited. The specification of the patent not having been enrolled, the composition could not be explained; the subject was therefore postponed until the patent should be complete Mr. Ransome also exhibited several specimens of his patent artificial stone and the process of manufacture explained (vide PATENT JOURNAL, No. 86). A model of an ingenious wedge and screw fid, the invention of Mr. J. Southam, was exhibited. By this contrivance the top masts of a ship may be lowered without slackening the rigging, or ending men aloft. Mr. Clyburn's plough dynamometer was briefly alluded to. The resistance of spiral springs enclosed in a rectangular case is ingeniously employed to measure the tension of the connecting chains of the plough, and a pencil index traces on a card, discharged over a roller, the indications of the moving force. It has been found by experiments carefully made with this instrument, that a single horse exerts a power capable of raising 33,690 lbs. one foot high per minute,-a result coinciding in a remarkable manner with the data of Watt, who made it 33,000 lbs. The thanks of the meeting having been voted to the several exhibitors, the Society adjourned.

Thomas Edmonds, of London, for a certain process or method of manipulation and treatment for the preparation of leather, whereby it becomes