The material being a second time withdrawn from the retort, it is to be thoroughly washed in warm water, until every appearance of acid has become completely removed, after which, being dried, and then ground in water, in the way white lead is usually treated, the material becomes fit for use.

The patentee has proposed to employ sulphuric acid in the retort, but in the second operation he sometimes uses nitric acid, and under certain circumstances, other acids. He has described a particular formed vessel to be used as a retort, but has not exhibited any figure, as the vessel may be variously constructed, without deviating from the general principle. Steam, under great pressure, is proposed, and most approved as the heating material, but fire may be applied directly to the under part of the vessel, and effect the same object.

Thus a variety of changes may be made in the modes of conducting the operation, all of which come within the contemplation of the patentee, and are claimed by him under the present patent.

[Inrolled January 1827.]

To PETER GROVES, of Liverpool Street, in the City of London, Esq. for his Invention of certain Improvements in making Paint or Pigment, for preparing and combining a Substance or Material with Oil or Turpentine, or other Ingredients.

[Sealed 14th July, 1826.]

THE subject of this invention is the production of a pigment or opaque basis for paint, which is to be prepared from lead ore. This pigment may be produced in two

ways; first, from the lead ore in its natural state; and secondly, from the slag or scoria of the ore, after being smelted.

In the first instance, the ore is to be pulverized, and treated in the way described in the preceeding specification, in combination with salt-petre and sulphuric-acid and may be more or less acted upon by the acid, according as its colours shall be required in approaching to whiteness.

It does not appear that the patentee intends in the present instance, to bring this material to the condition of pure white lead, but to produce a substance approximating to the character of white lead as respects its opacity, which is to form a pigment or basis of paint.

With this preparation of lead, the materials constituting colours are to be mixed. If the material of the colour is of such chemical character as will not be injured by the action of the acid, and of heat, then it may be mixed in the retort with the lead ore, and be ground, and otherwise prepared with the ore in the way above described; if the paint is of a character that will be injured by heat, it may be mixed with the lead ore, and the acid after it has been removed from the retort; or if it is subject to be effected by heat and acid, then it may be mixed with the pigment, after it his been thoroughly washed and dried as above directed.

In the second case, when the slag or scoria run from the lead ore in smelting is to be converted into a pigment, it is to be ground or pounded to powder, and then to be acted upon by acid in a retort, in the same way as the ore, but as the slag is much lighter than the ore, a greater quantity of acid will be necessary, though it need not be so strong; and that slag which is the least vitrified, is to be preferred.

This material, when prepared, may be mixed with paints of a dark colour, and will be found a very good pigment, considerably cheaper than white lead, and for browns, or blacks, and other dark colours, may in some cases be preferable.

[Inrolled September, 1827.]

TO EDWARD THOMASON, of Birmingham, in the County of Warwick, Goldsmith and Silversmith, for his having found out or Invented Improvements in the Construction of Medals, Tokens, and Coins.

[Sealed 9th November, 1826.]

THE improvements proposed by the patentee, are the attachment of raised rims to medals, by means of solder, instead of producing the rims by the pressure of the dies as heretofore.

When the medals has been struck on both faces of a circular piece of plated metal or silver gilt, it is proposed to attach round the periphery, a rim of silver or gold. This rim may be prepared in a flat state by a roller pressing a strip of metal into a long straight matrix, for the purpose of giving it a milled, or otherwise ornamented edge; or of raising or sinking letters, so as to form an inscription or motto. beat into a ring form,

the medal by solder.

The strip so prepared is then to be and attached to the outer edge of

The faces of these medals or tokens are to be prepared in a coining or fly-press, precisely in the way commonly practised, the only feature of novelty being the attachment of the rim by solder, as above said.

VOL. XIV.

[Inrolled January, 1827.]

3 B

Novel Enventions.

Burstall and Hill's Steam Carriage.

THE patentees of the Edinburgh Steam Carriage, which has been mentioned several times in our preceeding volumes, have brought to London a working model of their invention, for the purpose of demonstrating the practicability of running a Steam Coach upon ordinary roads. This model, which contains several improvements upon the former patent, is made upon a scale of three inches to the foot of the intended stage coach, which is, they say, in considerable forwardness.

As we have not yet reported the Specification of the last improvements proposed in connection with this invention, we shall not at present enter into a particular description of the model, but merely say that in our opinion the arrangements of the machinery do the patentees great credit; the model is neat and performs extremely well.

It is, however, to be remembered, this is but a model, and though the practicability of constructing a Steam Coach, that should be capable of travelling upon ordinary roads, may be demonstrated, (which we have never doubted,) yet it is by no means proved how far a sufficient speed can be obtained, or what economy may be derived in working a full sized Stage Coach b steam, instead of horses.

We present our readers with the following rude sketch of the model, by way of giving a general idea of its construction; when we report the specification of the last improvements, we shall enter more fully into the details, and perhaps be enabled to say something practically of its operations.

A, Water Cistern.-B, the Boiler.-C, Steering Wheel, with the Conductor.D, Steel Frame which carries the Boiler.-E, the Curved Steam Pipe to supply the Engines.-F, Hand Pump and Pipe to fill the Boiler.-G, Safety Valve.-H, Notice Cocks.-I, Eduction Pipe, to take the Steam from the Engine to Chimney.-K, the Crank.-L L, Pan for the Cinders.

The model is constructed on a scale of 3 inches to the foot, is 5 feet 6 inches long, 16 inches over the wheels, and 1 foot 10 inches high, the middle or propelling wheels being 13 inches in diameter.

"THE full size Carriage is intended to be about one foot longer than a two horse stage coach and horses. Seven feet four inches high to the roof, the wheels being the common breadth apart. It will be retarded or stopped in running down hill by a powerful lever and friction-break, which acts on the two fore wheels, within reach of the conductor; at the same time, by a crank and rod, the throttle valve is closed, which shuts off the steam. The engineer behind can at pleasure stop the engine.

The machine, with all its wheels smooth, and without either propellers, or any other adhesion on the ground, except the natural friction of the iron against the road, carries with ease and rapidity, up an ascent of one in eighteen, a weight equal to Forty Passengers upon a common stage coach, demonstrating that, on this plan, Stage Coaches may be propelled with safety, economy, and speed, not to be attained with horse coaches, and capable of making the present common roads of the country fully as economical as rail-roads, except in situations of extraordinary traffic.

The boiler is so constructed as to be perfectly safe, and the most timid person may view the working of the model without either danger or annoyance."