wrought with different brushes.

34. To paint in imitation of mahogany and maple.—First give the work one or two coats of straw coloured paint, composed of white lead and yellow ochre, ground in linseed oil, to which may be added a little fine litharge, that the paint may the sooner dry; when this is dry, rub it smooth with sand-paper. Then if mahogany is to be imitated, stain the work over with boiled linseed oil, coloured a little with venetian red and burnt terra-de-sienna, equal quantities. This should be applied with a short stiff brush, and spread very thin that it may not run, or drip off. Then with terra-de-sienna, ground very thick in oil, form the dark shades of the graining according to your design, with a small flat brush. For this purpose a common sash-brush may be made flat, by having a small piece of wire, or wood, bound on each side near the handle. Some of the darker shades may be drawn with burnt umber and black, ground together, which may be applied with a camel hair pencil. If any part is to be made very light, the staining may be wiped off carefully with a ball of cotton. Light stripes, or lines may be produced by drawing a piece of cork or soft wood over the work, thus taking off or removing the dark colours, that the original ground may appear.—To imitate maple, the work must be stained with yellow ochre, and burnt umber, ground together in boiled oil. Instead of burnt umber, terra-de-sienna (unburnt) is sometimes used, but as different kinds, or parcels of it, vary in colour, from yellow to brown, it may not be depended on uniformly. The birds' eyes and curls are formed by removing the staining from the ground with a piece of stiff leather, the edges of which are cut in notches so that the several points will touch the work at the same time.

35. The art of painting on glass.—If the common cakes of water-colours are to be used in this work, they should be mixed with water in which a little muriate of soda has been dissolved. Other paints may be ground in shellac varnish; or in linseed oil, but this will not dry so quick. The most proper colours for this work, on account of their transparency, are india ink, or lamp black, burnt umber, burnt terra-de-sienna, lake and gamboge or chrome yellow. These must be laid on very thin, that they may be the more transparent. Set up the glass on its edge, against a window, or place a lamp on the opposite side that the light may shine through, and with a fine hair pencil, draw the out lines of your design on the glass with black; afterward shade and paint it with the above mentioned colours, observing to paint that part of the work first, which in other painting would be done last. The shading may be performed by laying on two or more coats of the colour, where you want it darker. If transparency is not required, a greater variety of colours may be used, and laid on in full heavy coats. Any writing or lettering in this work, must be written from right to left, contrary to the usual order. In some pieces, the body of some of the principal objects, may be left blank, so that by placing pieces of silk or paper of different colours, on the opposite side of the glass the picture will also appear in different colours, and may be changed from one colour to another at pleasure.

36. Best method of polishing steel.—For this purpose a wheel must be provided that is perfectly round, and the rim of it covered with deer-skin, or buff-leather. The diameter of the wheel, for common purposes may be about two feet; but for polishing razors, and some other similar instruments, the wheel should not be more than five or six inches in diameter, and two inches thick. The steel must first be ground smooth as possible on a common, or fine grained stone; it may then be applied to the polishing wheel, which must be turned with such velocity that the surface, or rim, may move at the rate of from forty to sixty feet in a second; and the leather must frequently have a powder applied, called crocus of iron, which is prepared by calcining sulphate of iron in a crucible till it becomes a fine red oxide resembling rust. For ordinary work, the leather may be moistened with olive oil, that it may the better retain the powder; but it will give a more perfect polish if kept dry. If any perfectly plain surfaces, such as mirrors are to be polished, they must be applied to the sides of a wheel, and not to the edge or rim, in the manner of other work.

37. To make letters or flowers of blue, on polished steel.—Hold the steel over a charcoal fire till it becomes blue;—let it cool. Then with equal parts of rosin and bees wax, melted together, coloured a little with lamp black, and diluted with spirits of turpentine, so as to work freely with a camel hair pencil, draw any letters or figures on the steel, while it is a little warm. When the steel has become cold, wash it over with muriatic acid, diluted with two parts water, to one of acid; thus take off the blue colour, and then wash it with clear water. Afterward the varnish, being warmed a little, may be readily washed off with spirits of turpentine, and the letters or flowers will remain blue. Note.—If letters are formed of polished steel with this varnish, and the body of the metal be also covered with it, except a small space round the letters, and then bathed with muriatic acid, the space round the letters, will become a dull iron colour, while the letters and the body of the steel will retain their polished surface and brilliancy.

38. To preserve the brightness of polished steel.—Grind an ounce of native plumbago, (such as is used for making lead pencils,) very fine in a gill of spirits of turpentine; then add an ounce of clean bees wax; apply a gentle heat, till the wax is melted, and continue stirring it till it is nearly cold. Brush over the steel with this composition, and when the spirits have evaporated, rub the work hard with a piece of glove leather, and wipe off nearly all the wax, that the metal may retain its brightness. This may be applied to iron or steel in machinery, or other work, and will be found to answer a much better purpose than oil, as it is less liable to collect dust from the atmosphere, and is, in general, much more durable.

39. To give steel a temper to cut marble.—No temper can be given to steel, in which hardness is combined with tenacity, more than in that given to files, at the file manufactories, which is accomplished by the following process.—To boiling water, add about twice as much finely ground muriate of soda, as the water will dissolve, and as much rye flour as will, with the other, make a thick paste; lay a coat of this paste over the steel, (which must be ground, or filed previous to tempering,) and subject it to a full red heat, in a fire of charcoal, mixed with about a third part of animal coal, (coal of bones, horns, leather, &c.) and then suddenly plunge it three or four feet deep, in exceeding cold water. By thus immersing the steel rather deep in the water there is a double advantage; for the water which becomes heated, by contact with the steel, will rise and its place be supplied continually by fresh cold water; and at the same time, the pressure of the water on the coating of paste, will make it adhere more closely to the steel while it is cooling. The paste may then be shelled off, and the steel will be found as bright as before, or at least, will not have been essentially oxydized by the operation.

40. To wash iron or steel with copper.—Dissolve sulphate of copper in water, in the proportion of one to three; wash the iron or steel with it, and it will instantly be covered with reduced