suitable metal plate, in the ordinary manner, the plate is placed on a stove, having a flat top or slab, so as to form a table of sufficient size for the reception of the plate. The stove being fixed, the plate is retained on the flat top until it is sufficiently heated to render the colouring matter to be applied to it sufficiently liquid for working. The colouring matter is mixed with transferring oil, similar to that used by manufacturers of china and earthenware in preparing colours for ornamenting those substances, and when mixed, is rubbed over the plate until the engraved pattern or design is sufficiently filled. The plate is then scraped, and cleared of the superfluous colouring matter in the usual

manner.

A sheet of paper, adapted in dimensions to the engraving, and previously sized with a ley of soft soap or other suitable sizing matter, is then placed, whilst yet moist from the sizing, evenly over the plate, and the whole passed between the rollers of an ordinary engraver's press in the usual way. For this purpose the Patentees generally use tissue paper; but where the pattern is large, or contains a great body of colour, a stronger paper may be desirable.

The paper, bearing the impression in one colour only, when drawn off the plate, is ready to be transferred. The sheet must then be placed, with its printed face downwards, on the surface of the article intended to be ornamented, and must be brought into even and uniform contact by gently rubbing the back of the paper with the hand, or with a soft rubber, and is to be so left until the colour has been imbibed, or become sufficiently attached to the surface to which it is applied.

The paper being then soaked with a wet sponge, may be rubbed off without difficulty, leaving the coloured design completely transferred to the surface of the article, the previous operation of sizing which the paper has undergone,

disposing its fibres to part freely from the colouring matter, and to separate easily from the surface.

Where several colours are intended to be used in the same design or pattern, such parts only of the design or pattern as are intended to be in one of those colours is engraved on the plate; and it is most advisable that the finer parts of the design, such as the outlines, should be obtained from the engraved plate, leaving the body of the colouring to be filled in afterwards.

The sheet of paper, with the outlines of the design taken from the engraved plate, is to be laid upon a smooth block or slab of stone covered with a fine blanket, in order that the remainder of the pattern or filling may be supplied in the other colours. This is to be done by means of blocks, similar to those used by calico printers. The blocks are so formed and arranged, as exactly to correspond with the parts of the pattern previously obtained from the engraving, in order that they may form, when combined, a complete design.

It is evident that by this method, patterns in any required number of colours may be produced, each portion of the pattern being impressed from a separate block in a distinct colour, so that the impressions, when combined, may unite and form the complete design. When, however, the engraved parts of the pattern, consisting of outlines and shading, have been first given to the paper either in black, or in dark tints of any colour, the body colours may be applied by the blocks upon such shading or outline; for when the pattern is transferred from the paper to the surface intended to be ornamented, the outlines and shading being next the surface of the paper, will ultimately be found to lie on the exterior of the article so ornamented.

Besides blocks, metal types or similar implements for giving a coloured impression from a raised surface, may be

used for filling up the pattern; and many designs or patterns may be conveniently obtained from blocks or other raised surfaces alone, without having recourse to engraved plates; and as, in this case, the sized paper will not undergo the drying effect of the heated plate, it should, after sizing, be allowed to become nearly dry before being printed on by the blocks. It is, however, considered that the most ornamental and effective patterns may be obtained by the combination of impressions from an engraved plate and of blocks, in the manner described.

The first impression on the sized paper may be obtained by the process of lithography, instead of an engraved plate; and, in this case, the sized paper should also be used in a dryer state than when applied to a heated copper plate. For the purpose of applying the colouring matter to the surfaces of the blocks, composition rollers are to be used by the hand, the colouring matter being applied in a cold state.

With regard to the colours which may be used, the selection of these forms no part of the invention, but they must, in all cases, be such as are employed for the like purposes in ornamenting the respective substances to which the invention applies. The colour must, however, be mixed or prepared with a compound or transferring oil, hereinafter described.

When metalline powders are used as gold or silver, the metal having been first reduced to a pulverized form by the common process of solution and precipitation, is to be mixed with the transferring oil, and employed in the printing of the required pattern in the form of printing ink; and after being transferred to the surface of the article to be ornamented, must, when perfectly dry, be burnished until bright, and then varnished in the ordinary manner.

In the foregoing description, the methods of performing by a flat engraved plate, and by blocks applied by hand,

has been described; but the same may be more advantageously effected, that is, to a larger extent, and with less expenditure of labour, by the employment of machines, similar in construction to those used by calico printers. These are, first, a cylinder machine, whereby a pattern, or part of a pattern, is obtained from an engraved copper roller continually revolving, and which, as it revolves, is constantly supplied with colouring matter from a trough, and is cleared of its superfluous colour by a scraper. Secondly, a flat press, wherein a pattern, or part of a pattern, is obtained from a flat plate, the colouring matter being furnished by flexible inking rollers or dabbers, and the superfluous colouring cleared away by a scraper; and thirdly, a surface printing machine, in which a pattern, or a part or several successive parts of a pattern, are obtained from rollers, called surface rollers, in which the por tions intended to give the impression are raised as in the blocks worked by hand, and which are inked by flexible colouring rollers. It is, however, unnecessary to describe these machines, as they form no part of the invention; the cylinder machine and flat press, with their adaptations, having been fully described in the specification of a patent dated the 17th of September, 1831, granted to John Potts, Richard Oliver, and William Wainwright Potts, (see vol. i. of our Conjoined Series, page 126,) the surface printing machine with its adaptations, and the manner of using the same, being fully described in the specification of another patent granted 3d December, 1835, to William Wainwright Potts (see vol. ix. of our Conjoined Series, page 158). Patterns may also be obtained by the employment of any of the presses in common use among letter-press printers.

The surfaces intended to be ornamented may either require to be prepared or not: for instance, if wood be the

VOL. X.

C

substance to be ornamented, the surface may either be made clean, or it may be covered with a varnish; if iron, or other metal, the surface may be clean, or japanned, or varnished, and so in respect to other substances to which the improved process is intended to apply, the ordinary modes of preparation being employed where found expedient, according to the discretion of the operator.

The soap ley or material to be used for sizing the tissue paper, and also the transferring oil for mixing the colour, are of the kinds in common use among manufacturers of earthenware, and are to be obtained in the potteries ready for use; but it may be desirable to state the methods of preparing these articles, although they form no part of the invention.

The ley or size is prepared by boiling soft soap in water, with a little of the common soda of commerce, in the proportions of about one pound of soap and an ounce of soda to a gallon of water. These must be boiled until the soap and soda are well dissolved in the water. The size may be applied to the paper by a brush or sponge, or by the paper being passed between rollers covered with blankets, the lower one revolving in a trough filled with the size.

The transferring oil is prepared by boiling together linseed oil and rape oil, in the proportions of one quart of linseed oil to half a pint of rape oil, adding to them whilst boiling one ounce of white lead, the like quantity of common white or brown resin, and the like quantity of common tar. These ingredients are to be boiled over a clear red fire. When the boiling has continued about half an hour, the liquid must be fired with a lighted paper and allowed to burn, extinguishing the flame when the boiling becomes too violent, and repeating the firing until the liquid becomes ropy. Its being sufficiently reduced or inspissated, may be ascertained by dropping a little on a