tinguished for their taste and skill in this branch of engraving. By this art books are usefully and cheaply embellished.

II. ENGRAVING ON COPPER is performed either with the graver, or with nitric acid. For the first called stroke or line engraving there needs but little apparatus and few instruments. 1. Stroke or line Engraving. The plate to be worked on being first well polished, is covered over with a thin coat of virgin wax, and on this the draft or design, done in black lead, red chalk, &c. is laid, and rubbed down for the wax to take off. The design thus transferred upon the wax is traced through on the copper with a point or needle; then heating the plate and taking off the wax the strokes remain on the plate, which must be retouched and heightened according to the skill of the artist. The graver is a steel point, very sharp and well tempered. In the conduct of the graver consists all the art. The other instruments are scrapers, a burnisher, and a cushion for bearing the plates, &c. This process may, with propriety, be classed as a species of dry pointing.

2. Etching is a method of engraving on copper, in which the lines, or strokes, instead of being cut with a tool, or graver, are corroded with nitric acid. Etching was invented much about the same time with engraving on copper, properly so called, by Albert Durer, and Lucas. It has several advantages over that art; it is done with more ease and expedition; it requires fewer instruments; and even represents different subjects better and more agreeable to nature, as landscapes, ruins, grounds, and all small, feint, loose, remote objects, buildings, &c. The method of etching is thus:-the plate being well polished, is heated over the fire: and when hot covered with a peculiar ground, or varnish. When cold again, the ground is blackened with the smoke of a candle; and on this ground, thus blackened, a tracing from the design is laid. The method of tracing a drawing is by placing a piece of transparent oil-paper, the size of the design, over it, and then with a black lead pencil the drawing is traced on the transparent paper:-this finished, the tracing is laid upon the etching ground, and fixed at each corner by means of small pieces of wax, a piece of white paper first rubbed well all over on one side with red chalk is now in

troduced between the transparent paper and the ground upon the copper: this done, the tracing or drawing must be very minutely and accurately traced with a blunt-pointed needle; which pressing the paper close down to the ground, occasions the wax therein to lay hold of the chalk, and so bring off the marks of the several lines; so as at length to show a copy of the whole design in all its correctness.

The draft thus traced, the artist proceeds to draw the several lines, with a point, through the ground, upon the copper. To finish his work, he makes use of points of different sizes; and presses on them sometimes more strongly, and sometimes more lightly, according as the several parts of the figures, &c. require more or less strength or boldness; some of the points being as fine as needles, for the tender hair strokes, and the remoter objects; and others as large as bodkins, made of an oval shape, for the deeper shadows, and the figures in the front of the work. A rim, or border of wax, is then raised round the circumference of the plate, and the nitric acid reduced by two-thirds of water, poured on; which is thus kept from running off at the edges. The ground being impenetrable to that corrosive liquid, the plate is defended from it every where but in the lines, cut through it with the points; which, lying open, the acid passes through them to the copper, and eats into it, to the depth required; which done, it is poured off again.

3. Aquatinta is a method of etching on copper, lately invented, by which a soft and beautiful effect is produced, resembling a fine drawing in water colours or Indian ink. Previous to that operation upon the plate, a powder must be prepared of asphaltum and resin or gum-sandarach. Then the copper being polished, lay the etching ground upon it, and etch the outlines in the usual way, then soften the ground with a little grease and wiping it off, leave only as much grease as will dim the copper, then sift the powder upon the surface of the plate, and as much as is necessary will adhere to the grease, the other may be shaken off; and by holding the plate over a charcoal fire, the powder which adhered to the grease will be fixed to the plate. When the plate is cool, all the light places where there is no work or shades must be covered with ivory black mixed with turpentine varnish. The acid

is now to be poured on, being first reduced to a proper strength by vinegar or water. Let it stand five minutes for the first shade, then pour it off and wash and dry the plate. Then stopping up the light with the varnish, pour on the acid for the second tint, and let it stand five minutes more, and proceed in this manner for every tint till you have produced the darkest shades. In etching landscapes, the sky and distant objects are performed by a second operation, and the application of a fine powder. Sandby, Parkyns, and Jukes, have been eminent in this branch of engraving.

4. Mezzotinto. Prince Rupert, of Germany, first invented this particular manner of representing figures on copper, so as to form prints in imitation of painting in Indian ink. The method is very different from common engraving. To perform it, the surface of the plate is traversed all over, with an instrument termed a grounding tool made on purpose, first one way, and then the other, across, &c. till the surface of the plate be entirely furrowed with lines close to each other, so that if an impression was then taken from it, it would be one uniform mass of black. This done the design is drawn, or marked, on the same face; after which they proceed with burnishers, scrapers, &c. to expunge or take off the rough ground made by the tool, until they come to the surface of the copper, in all the parts, where the lights of the piece are to be, and that more or less, as the lights are to be stronger or fainter; leaving those parts black which are to represent the shadows or deepenings of the draught. The instruments used in this kind of engraving are cradles, scrapers, and burnishers. The art of scraping mezzotintos has been applied to the printing with a variety of colours, in order to produce the resemblance of paintings.

5. Stippling is performed by making dots on the copper, and working the plate in such a manner as to have somewhat the appearance of a mezzotinto; but infinitely preferable, as it affords a softer, and yet more spirited effect. It is also a species of engraving in imitation of chalk drawings. Ryland and Bartolozzi were the most distinguished in this art. 6. Calcography. This mode of engraving is a modern invention by Hassell, to imitate pencil, chalk, and pen and ink drawings, for which he has been rewarded and honoured

by the Society of Arts, with their medal and a purse of thirty guineas. For particulars of this art, see Hassell's Calcographia.

7. Coloured Engravings. (1.) About the time of the revival of learning, some artists produced prints of differents colours, by means of wood-cuts, employing a different plate for each colour. But so much inconvenience and imperfection attended this method, that it was seldom resorted to. No further improvement was attempted, till near the middle of the eighteenth century, when somexperiments were made by French artists, with copperplates, with a view to obtain coloured prints. They also found it necessary to use different plates for different parts of the work; and on this, as well as other accounts, the expense of their plan prevented its general adoption. Towards the close of the last century, a method was invented in England of producing an elegant coloured engraving from a single copper-plate.

(2.) Mr. J. R. Smith, an engraver, of London, invented a method of taking impressions from his own plates, which so nearly resembled oil-puintings, as to be, with difficulty, distinguished from them by connoisseurs. These impressions are said to possess that sort of brightness, which is so much admired in Venetian paintings-to resemble them also in permanency--and, to be of such a nature as to render a covering of glass, so expensive and frangible a material, altogether unnecessary. A method of engraving closely resembling drawings, was invented by that celebrated artist Mr. Westall. In 1799, he exhibited a drawing, and the year following a print taken from it, which was so close an imitation, as completely to deceive the eye.

III. ENGRAVING ON STEEL, or DYE SINKING. This is chiefly used in cutting seals, punches, matrices, and dies for striking coins or medals. The method of engraving with the instruments, &c. is the same for coins as for medals and counters; the only difference is in the relievo, that of coins being less than that of medals, and that of counters less than that of coins. Engravers in steel commonly begin with punches, which are in relievo, and serve for making the creux, or cavity, of the matrices and dies: though sometimes they begin with the creux, but only when the work is to be cut very shallow.

IV. ENGRAVING ON PRECIOUS STONES. In engraving diamonds, the first thing is to cement two rough diamonds to the ends of two sticks, held steadily in the hand, and rub or grind them against each other, till they are brought into form. The powder serves to polish them, which is performed with a mill turning an iron wheel. The diamond is fixed in a brass dish, and applied to the wheel, and covered with diamond dust, mixed with oliveoil, and first one face, then another is applied to the wheel. Rubies, sapphires, and topazes, are cut and formed on a copper wheel, and polished with tripoli diluted in water. Agates, amethysts, emeralds, rubies, and the softer stones, are cut on a leaden wheel, moistened with emery and water, and polished with tripoli, on a pewter wheel. Lapis-lazuli, opal, &c. are polished on a wooden wheel. To fashion and engrave vases of agate, crystal, &c. a lathe is used, on which are the tools, turned by a wheel; and the vessel is held to them to be engraven, either in relievo or otherwise; the tools being moistened, from time to time, with diamond-dust and oil, or emery and water.

V. ENGRAVING ON GLASS. To effect this kind of engraving, a glass-plate is covered with melted wax, or mastic. When this coating becomes hard, it is engraven upon by a very sharp-pointed needle, or other instrument of that kind. A mixture of oil of vitriol and fluoric acid, is then put upon the plate, and the whole covered with an inverted china vessel, to prevent the evaporation of the acid. In two days the plate being cleared of its coating, exhibits all the traces of the instrument. It succeeds very well in the outline representation of philosophical instruments and chemical apparatus. The fluoric acid was discovered by Margraaf and Scheele.

Select Books on Engraving.

Landseer's Lectures on Engraving, delivered at the Royal Institution, 8vo. Meadows' Lectures on Engraving, delivered at the Surry Institution, 8vo. Gilpin's Essay on Prints, 12mo. Hassell's Calcographia,

CHAP. VII.-MUSIC.

1. MUSIC is both an art and a science, and in either case, its object is the combining of sounds in a manner that shall be agreeable to the ear. This combination be

may