cise shape, form, or dimensions of those shewn in the drawings. [Inrolled in the Rolls Chapel Office, October, 1840.]

TO HENRY PHILIP ROUQUETTE, late of Norfolk-street, Strand, in the county of Middlesex, but now of Marklane, in the City of London, merchant, for a new pigment.-[Sealed 25th March, 1840.]

THE patentee says, I take oxide of zinc, either in the state commonly called flowers of zinc, (by which I mean the fine particles that detach themselves, and are carried off by the strength of the fire, in the manufacture of zinc or spelter) or in the state of scoria or sublimate, as it is found in the upper part of furnaces, where iron or other ore containing zinc or spelter is worked, and in that state commonly called tutty; or in the state of dust, dross, or scum, as produced by the re-melting of the metal in zinc rolling works, or as it is found, sublimed or otherwise, in factories where brass is made; or I take a mixture of flowers of zinc, in equal parts, with either of the other before-named materials, which I prefer and submit it to my first, or burning process, as follows:

Having spread it in a finely pulverized and sifted state, on the bottom of an ordinary oven or furnace, in a layer of about two inches thick, I heat it till it ignites, keeping the bottom of the oven at a cherry-red heat, as long as any flame is emitted from the layer, and stirring the layer the whole time. When it ceases to flame, the burning for the purposes of the said invention is completed, and the ashes or remaining oxide being removed from the oven, are put into iron troughs to cool, and when cool, are passed through a fine sieve. The fine powder thus obtained, I

then submit to my second process of washing or elutriation, which may be accomplished by any of the ordinary methods, but that which I prefer is as follows:

I place a cask, filled with pure cold water, on a stand about three feet from the ground. This cask must have two discharge holes in it, one above the other, (the lower one being about one-third of the height of the cask, from the bottom, and the upper one about two-thirds) these holes must be stopped with plugs; the aforesaid sifted oxide or product, from the oven, being placed in the water, it should be stirred briskly for a minute or two with a stick, and the upper plug then removed, when the water, which will be highly charged at first, should be allowed to run off into a vessel placed below to receive it.

It should be allowed to run off in this manner till the water runs clear, when the upper hole should be plugged again, and the lower hole opened, and the discharge allowed to continue till the water also runs clear from that hole, and then the lower hole should be plugged again. The liquid mixture thus obtained, should be allowed to settle, and the clear surface water then poured off. The sediment thus obtained should then be placed in a slow oven, or in the sun to dry, partially; and when, by evaporation, it has become of the consistence of paste, it is to be cut or divided into cakes of three to four, by two to three inches in size, and replaced in the slow oven, or exposed to the sun to be thoroughly dried. In this state the cakes are to be ground with oil in the same manner as white lead cakes are now treated, and when so ground, make the said pigment; more or less oil or tar being used, according to the purposes for which I require it.

Now, whereas, I claim as the said invention, a pigment formed by oxide of zinc, produced by burning, washing, or elutriation, and drying, as aforesaid, unmixed or mixed

with oil, or other suitable liquid; and if mixed, then in proportions varying according to the purposes to which the said pigment is to be applied.—[Inrolled in the Rolls Chapel Office, September, 1840.]

TO HENRY DIRCKS, of Liverpool, in the county of Lancaster, engineer, for certain improvements in the construction of locomotive steam-engines, and in wheels to be used on rail and other ways, part of which improvements are applicable to steam-engines generally. — [Sealed 12th May, 1840.]

THE first part of this invention, namely, improvements in the construction of locomotive steam-engines, consists in a novel arrangement and construction of exhaust or exit pipes, by which the eduction steam from the cylinders is conducted into the chimney, and at the same time is caused to act in very small jets upon the gas smoke, or heated vapour, toward the back ends of the tubes in the boiler, and thereby produce a consumption of the smoke emitted from the furnace, in those engines where coal is used, and the boilers are of a tubular construction.

The principal feature of this improvement consists in dividing the exhaust or eduction pipe (which is placed in the smoke box of the engines as usual) into a series of small branches or tubes, and so arranging or spreading these tubes that they may be opposed to most of the ends of the boiler tubes, in the smoke box; and, as the exhaust branches or tubes are perforated with small holes on those sides of the pipes opposed to the tube ends, the steam will blow out upon the orifices at the ends of the boiler tubes, in very fine jets, and thus prevent the emission of smoke.

This part of the improvement is applicable to steam-engines generally.

Secondly,-improvements in the construction of wheels to be used upon rails, or other roads, or ways, which consist in forming the tyre of the wheel of cast or wrought iron, having a channel or groove formed in it, to be filled with blocks of wood, the grain of the wood being placed radially or endways all round, in segments, and which are afterwards bolted or riveted, or otherwise fastened in the channel of the tyre, presenting a wooden periphery or rim to the road or way.

The wood used for this purpose is African oak, British oak, beech, or other hard wood, previously soaked or saturated with coal gas tar, and impregnated therewith by means of hydraulic or other pressure, in order to fill up its pores, and thus prevent the admission of moisture.

Instead of the use of hard woods, softer timber, such as larch, &c., may be employed, and previously squeezed or pressed into more perfect solidity; and it is further observed that the wood may be otherwise chemically prepared, in order to prevent the admission of moisture, or the pores may be filled by any oily substances being either pressed into the pores of the timber, or introduced by vacuum, or other means.

In Plate X., fig. 1, represents a transverse section, taken vertically, through the smoke box of a locomotive engine boiler; and fig. 2, a longitudinal section of the same, exposing the ends of the boiler tubes, the cylinders, and the eduction or exhaust pipes. The smoke box is represented at a, a, attached, as usual, to the end of the boiler b, b. The tubes are shewn at c, c, which open as usual into the smoke box. The steam cylinders d, d, communicating, as in common, with the lower end of the exhaust or exit pipe e, e. This pipe, instead of beng carried

upwards directly into the chimney f, is branched or spread into several small pipes or tubes g, g, g, perforated with small holes in the sides, opposed to the tubes c, c, and are then again connected, at their upper ends, to the exhaust or exit pipe h, leading to the chimney f.

There is also an auxiliary pipe i, i, the cock of which is to be opened by the engine-man, to supply steam from the boiler to the branch pipes g, g, g, when the engine is stationary, and the supply cut off from the cylinders. The steam thus blowing out of the perforated exhaust pipes g, g, opposite the back end of the boiler tubes, will thus prevent the passage of smoke to the flue or chimney,

Fig. 3, represents a front view of the improved wheel; fig. 4, a side or edge view of the same; and fig. 5, a section, taken vertically through the middle of the wheel. a, a, represents the ordinary parts of a cast or wrought metal wheel, having the rim or tire formed as a channel or groove, in which are fixed the several segments of wood b, b, having the grain placed radially, and extending around the tire, in order to form the running or outer periphery. These segments of wood may be fastened into the metallic channel by various means,-by bolts or rivets, as shewn at c, c, or by turning a groove half in the metal and half in the wood, and running metal therein, as shewn at d, d. Figs. 6 and 7, represent detached segments, and shew both modes of fastening them to the metallic body of the wheel.

The patentee claims, firstly,-The improved construction and arrangement of the exhaust or exit pipe, used in combination with tubular boilers, in the manner and for the purposes herein set forth; and, secondly,-The combination of a metallic wheel with a wooden-faced tire, as before explained, without being confined to its precise mode of construction or putting together.—[Inrolled in the Rolls Chapel Office, October, 1840.]