the inner ends of the spokes a, a, and the ring b, b, as shewn in the figure.

By securing the wrought-iron arms to a ring of wroughtiron, previously to casting the metal around the ends of such arms to form the nave or boss, an increased security will be given to the arms in the nave or boss, and greater strength and durability will be obtained.

The second part of the improvement consists in placing or inserting a hoop, bar, or segments of steel, iron, or hard metal, in a groove, turned or otherwise formed, entirely around the outer rim or periphery of a railway wheel, such groove being properly shaped to receive the steel or other hard metal. Fig. 2, represents a section, taken transversely through a railway wheel. d, d, d, represent the rim or periphery, arms, and nave. The improvement consists in forming a groove b, b, either dove-tailed, (as shewn in the figure, or otherwise,) shaped entirely around the outer rim or periphery, whatever the material of the wheel; and in placing or inserting therein a hoop, bar, or segments of steel, iron, or hard metal, either in one entire piece around the circumference of the wheel, or in smaller pieces or segments, placed together, end to end, so as to fill the groove formed round the periphery of the wheel. Fig. 3, represents, in section, a portion of the felloe or rim and tyre of a railway wheel; and fig. 4, is a similar section, excepting that in the latter the steel bar, hoop, or segment c, is represented as about to be placed in the groove b, b; which groove is shewn as it is cut or formed in the felloe or rim, previously to the steel being inserted. The bar, hoop, or segments of steel, or other hard metal, being heated, are introduced into the groove, and spread laterally, so as to fill or become tight in the groove, by hammering or other pressure, as represented in fig. 3.

Steel or other hard metal, as above described, may be applied to the working surface of the flange of the tyre. A separate groove may be made in the flange, or the groove shewn in the drawing may be extended further towards the flanged side of the wheel, so as to steel that part of the flange on which the friction, against the edge of the rails,

principally takes place. In applying this improvement to the tyres of wheels, whether new or old, made according to the usual method, it will be necessary to form the groove to the requisite size and shape; or if a groove be left, when the tyre is formed, it may be enlarged, according to the wishes of the manufacturer, to receive the steel; and the above-mentioned hoop, bar, or segments of hard metal, may be easily removed when worn, and renewed from time to time, as long as the general fabric of the wheel is sufficiently firm for use.

*

The patentee, in conclusion, states that he is aware of steel having been used, before the date of his said letterspatent, for the tyres of wheels, to be employed on common roads and railways, by other persons, and under letterspatent, granted to Daniel Gooch, bearing date on or about the 28th day of May, 1840, for the use of steel in wheels for carriages and locomotive engines, to be used on railways, by forging or welding together bars of iron and steel; that he does not, therefore, claim the use of steel generally on tyres for railway wheels, or the use of steel on such tyres, when the iron and steel are welded together in the formation of the tyre-bar; but he does claim the improvement in the tyres of wheels, to be employed on railways, by inserting a hoop, bar, or segments of steel, or other hard metal, in a groove, turned or formed entirely round the rim or tyre of such wheels, as above described.—[Inrolled in the Petty Bag Office, December, 1842.]

Specification drawn by Messrs. Newton and Son.

TO MOSES POOLE, of Lincoln's Inn, Gent., for improvements in treating, refining, and purifying oils, and other similar substances, being a communication.-[Sealed 21st February, 1842.]

THESE improvements consist in purifying and refining oils, and other similar substances, by means of alkaline and acid solutions. The place in which the operation is car

*For Specification of this Patent, see Vol. XVIII., p. 84, Conjoined Series.

ried on is kept at a temperature of from 700 to 80° Fahr.; and thus the congealed portions of the oil, if any, become melted, and the grosser parts deposited, previous to the purifying process. When the precipitated matters have been separated from the oil, a solution of potash or soda, * containing from four to eight per cent. of the alkali, is stirred up with it for about an hour: this solution may be rendered caustic, if considered necessary, by the addition of lime. The oil is then drawn off, and after being allowed to rest for from twenty-four to thirty-six hours, the scum, which will appear on the surface, is removed. After this, about ten per cent. of water, containing four or five per cent. of concentrated sulphuric acid, and heated to from 110° to 120o, is added to the oil, and the mixture well agitated for about a quarter of an hour; it is then allowed to rest for about forty-eight hours, and is afterwards filtered.

The patentee claims the mode of purifying animal and vegetable oils, and such like substances, by subjecting them to acid and alkaline solutions.-[Inrolled in the Inrolment Office, August, 1842.]

TO FREDERICK THEODORE PHILIPPI, of Belfield Hall, in the county of Lancaster, calico printer, for certain improvements in the production of sal-ammoniac, and in the purification of gas for illumination,-being a communication.-[Sealed 21st July, 1842.]

THE chief object of this invention is to purify coal gas, by removing from it, by means of a double chemical decomposition, all the ammoniacal substances with which it is combined, and at the same time separating from it a large quantity of naphtha, or naphthaline, both of which substances render its smell very disagreeable. Ammonia is found in coal gas, combined with hydrosulphuric acid, carbonic acid, sulphurous acid, hydrocyanic acid, hydrosulphocyanic acid, &c., &c. Now, if the gas is subjected to the action of a saline metallic solution,-for instance, of manganese, iron, zinc, copper, lead, antimony, &c.,-the

result will be a double decomposition: the formation of a metallic sulphuret or carbonate, sulphite, cyanuret, &c., which will be precipitated, whilst the ammonia will be held in suspension by the solution employed. The sulphate or chloride of manganese is preferred to be used in the formation of the solution, on account of its cheapness. The solution should not be acid, as that would cause a decomposition of the hydrosulphates, carbonates, sulphates, and the disengagement of the acids. It is rendered neutral by using the condensed ammoniacal water from the gas-works, and should be reduced by this means to the strength of 20o Beaumé. In order to obtain the double decomposition, the gas is passed through the solutions mentioned above, contained in suitable cisterns or apparatus. This apparatus consists of three cisterns, or wash boilers, one placed higher than the other; through these the gas passes, and is washed. The cisterns or wash boilers are cylindrical, and made of wrought or cast-iron; the lids should be so much above the level of the liquid, that the bubbling, due to the passage of the gas, should not reach them; they should be easy of removal, and be closed with a water-joint.

The pipes for admitting and letting off the gas are placed at the side, and the remark, made with reference to the distance of the lids, is partly applicable to the letting-off pipes, which might be covered by the precipitate. If preferred, the lids may be fixed, and provided with a man-hole for inspecting and cleansing the cistern. The pipe for admitting the gas descends, at least, two inches below the surface; the gas is separated in its passage, in order to increase the surfaces of contact, and this is effected by perforated plates of metal, or other like partitions. There is in each cistern an agitator, which is so constructed, as to put in motion all the deposit, particularly at the bottom and sides of the apparatus, when the cistern is to be emptied. The pipes and taps for emptying should be large, and capable of being removed, when necessary. There is an escape-pipe attached to each cistern, to prevent an increase of pressure, in case the level of the liquid should by any cause ascend;

the escape-pipe conducts the liquid into the lower cistern, as seen in the drawing hereafter particularly described. The gas is allowed to pass through the cisterns until the liquid in the first, instead of being precipitated by the means of a hydrosulphate, contains an excess of ammonia, as in the ammoniacal or condensed waters. To find out this point of saturation, a small quantity of the solution is drawn from the cistern by a little tap. The liquid of the first cistern being saturated, it is drawn off, the second cistern is emptied into the first, the third into the second, and the third has a fresh supply of the solution introduced. The cisterns are connected by pipes, and they are made in such a manner as to allow of being cleaned. The solution from the first cistern is received into a vat, in which it forms a deposit; the liquid part is withdrawn, acted upon by a little sulphuric, hydrochloric, or other acid, according to the nature of the salt which saturates the ammonia, and then it is evaporated to crystallize. This process is also applicable for removing the ammoniacal substances which are disengaged during the distillation of bones, or other animal substances, and all such as produce ammonia by the action of heat. Naphtha, or naphthaline, which is found in distilling coal, is naturally volatile, and becomes more so in the presence of ammonia; there is a sort of affinity between ammonia and naphtha, which is destroyed when the ammonia is absorbed; the naphtha or naphthaline then floats on the liquid, or else it remains in the precipitate. In applying the process of purifying to gas, the gas should be cooled, and a great part of the tar and ammoniacal water should be condensed.

In Plate XV., fig. 1, is a sectional elevation of the apparatus employed for purifying gas. a, a, a, are cylindrical or wash cisterns, b, b, b, pipes which admit the gas to each cistern, c, c, c, agitators, provided with arms, t, t, t. The shafts of these agitators pass through stuffing-boxes at the top of the cistern a ;-d, d, d, are escape or overflow pipes, provided with slides and stuffing-boxes, by means of which, they can be cleaned without losing any gas, and without stopping the apparatus; e, e, e, pipes, with fun