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ETCHING.

ETCHING is a manner of engraving on copper, in which the lines of strokes, intead of being cut with a tool or graver, are corroded in with aqua fortis.

It is a much later invention than the art of engraving by cutting the lines on the copper, and has many advantages over it for some purposes, though it cannot supersede the use of the graver entirely, as there are many things that cannot be etched so well as they can be graved.

In almost all the engravings on copper that are executed in the stroke manner, etching and graving are combined, the plate being generally begun by etching, and finished with the graver. Landscapes, architecture, and machinery, are the subjects that receive most assistance from the art of etching ; for it is not so applicable to portraits and historical designs.

We shall first describe the various instruments and materials used in the art.

Copper-plates may be had ready prepared at the coppersmiths, by those who reside in large towns; but when this cannot be had, procure a piece of pretty thick sheet-copper from a brazier, rather larger than your drawing, and let him planish it well; then take a piece of pumice-stone, and with water rub it all one way, till the surface is as smooth and level as it can be made by that means: a piece of charcoal is next used with water, for polishing it still farther, and removing the deep

scratches made by the pumice-stone; and it is then finished with a piece of charcoal of a finer grain, with a little oil.

Etching-points or needles are pointed instruments of steel, about an inch long, fixed in handles of hard wood, about six inches in length, and of the size of a goose-quill. They should be well tempered, and very accurately fixed in the centre of the handle. They must be brought to an accurately conical point, by rubbing upon an oil-stone, with which it is also very necessary to be provided. Several of these points will be necessary.

A parallel-ruler is necessary for drawing parallel straight lines with. This is best when faced with brass, as it is not then so liable to be bruised by accident.

Compasses are useful for striking circles and measuring distances.

Aqua fortis, or what is better, spirits of nitre, (nitrous acid,) is used for corroding the copper, or biting-in, as it is called. This must be kept in a bottle with a glass stopple, for its fumes destroy corks. A stopple made of wax will serve as a substitute, or a cork well covered with wax.

Bordering-wax, for surrounding the margin of the copper-plate when the aqua fortis is pouring This

may be bought ready prepared, but it may be made as follows.

Take one-third of bees-wax to two-thirds of pitch ; melt them in an iron ladle, and pour them, when melted, into water lukewarm; then mould it with your hand till it is thoroughly incorporated, and all the water squeezed out. Form it into rolls of convenient size.

Turpentine varnish is used for covering the copper-plate with, in any part where you do not wish

on.

the aqua fortis to bite.

fortis to bite. This may be diluted to a proper consistence with turpentine, and mixed with lamp-black, that it may be seen better when laid upon the plate.

Ectching-ground is used for covering the plate all over with, previous to drawing the lines on it with the needles. It is prepared in the following

manner.

Take of virgin-wax and asphaltum, each two ounces, of black pitch and Burgundy pitch, each half an ounce; melt the wax and pitch in a new earthenware glazed pipkin, and add to them, by degrees, the asphaltum, finely powdered. Let the whole boil till such time as that, by taking a drop upon a plate, it will break when it is cold, on bending it double two or three times between the fingers. The varnish, being then enough boiled, must be taken off from the fire, and letting it cool a little, must be poured into warm water, that it may work the more easily with the hands, so as to form into balls for use.

It must be observed, first, that the fire be not too violent, for fear of burning the ingredients; a slight simmering will be sufficient; secondly, that while the asphaltum is putting in, and even after it is mixed with them, the ingredients should be stirred continually with a spatula ; and thirdly, that the water into which this composition is thrown, should be nearly of the same degree of warmth with it, to prevent a kind of cracking, which happens when the water is too cold.

The varnish ought always to be harder in summer than winter, and it will become so if it be suffered to boil longer, or if a greater proportion of the asphaltum be used. The experiment above mentioned, of the drop suffered to cool, will de

Roll up

termine the degree of hardness or softness that may be suitable to the season when it is used.

To lay the ground for etching, proceed in the following manner: Having cleaned the copperplate with some fine whiting and a linen rag, to free it from all grease, fix a hand-vice to some part of it where no work is intended to be, to serve as a handle for managing it by when warm. šome coarse brown paper, and light one end; then hold the back of the plate over the burning paper, moving it about until every part of it is equally heated, so as to melt the etching-ground, which should be wrapped up in a bit of taffety, to prevent ảny dirt that may happen to be among it, from mixing with what is melted upon the plate. If the plate be largè, it will be best to heat it over a cħafing-dish with some clear coals. It must be heated just sufficient to melt the ground, but not so much as to burn it. When a sufficient quantity of the etching-ground has been rubbed upon the plate, it must be dabbed, or beat gently, while the plate is hot, with a small dabber, made of cotton, wrapped up in a piece of taffety, by which operation the ground is distributed more equally over the plate than it could be by any other means.

When the plate iš thus uniformly and thinly covered with the vàrnish, it must be blackened by smoking it with a wax taper. For this purpose twist together three or four pieces of wax taper, to make a larger fame, and while the plate is still warm, hold it with the varnished side downwards, and move the smoky part of the lighted taper over its surface, till it is made almost quite black; taking care not to let the wick touch the varnish, and that the latter get no smear or stain. In laying the etching-ground, great care must be taken that no pår

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ticles of dust or dirt of any kind settle upon it, as that would be found very troublesome in etching; the room, therefore, in which it is laid should be as still as possible, and free from dusti

The ground beitig how laid; and suffered to cool, the next operation is to transfer the design to the plate.

For this purpose a tracing on biled paper inust now be made, from the design to be etched, with pen änd ink; having a very small quantity of ox's gall mixed with it, to make the oiled paper take it; also a piece of thin paper, of the same size, must Be rubbed over with red chalk, powdered, by means of some cotton. Then laying the red chalked paper, with its chalked side next the ground, on the plate, put the tracing over it, and fästen them both together, and to the plate; by a little bit of the bordering wax.

When all this is prepared; take a blunt etching needle, and go gently all over the lines in the tracing; by which means the chalked paper will be pressed against the ground, and the lines of the tracing will be transferred to it: oni taking off the papers, they will be seen distinctly.

The plate is now prepared for drawing through the lines which have been marked upon the ground. For this, thé etching-points or needles are employed, leaning hard or lightly; according to the degree of strength required in the lines: Points of different sizės änd forms are also used; for making lines of different thickness, though commonly this is effected by the biting-in with the

aqua fortis.

A margin or border of wax must now be formed all round the plate, to hold the aqua fortis when it iš poured on. To do this, the bordering wax

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