The arts of engraving and lithography bear the same relation to drawing, that the art of printing does to that of writing; the first being intended for the expression of original designs, the latter for the multiplication of copies of the design, when made.

ENGRAVING.

Origin.--The origin of copperplate engraving appears to have been in the fifteenth century, previously to which time it was probably unknown. The first inventors of engraving, were the goldsmiths, who, from the habit of marking ciphers and little devices on their wares, acquired a dexterity and despatch in the use of the graving tool, and at the same time, a power of producing subjects of such neatness and delicacy, that a desire was naturally excited in them, to preserve and increase the products of the art, by transferring them to paper. This object was effected by the use of a suitable pigment, and the aid of the rolling press.

Materials.--Common engraving differs from printing, in having its subjects or devices cut into, or below, the surface of a metallic plate, instead of being elevated or raised above it, as in types, and wood cuts. For the purpose of engraving, a variety of metals have been employed, and various combinations or alloys. Copper has, however, been selected by common consent, as uniting the greatest number of desirable qualities; having sufficient softness to permit it to be cut when cold, and sufficient hardness and tenacity, to resist the action of the press, and the wearing of continued friction. A plate of the best copper is selected, about one fourth of an inch thick, having one side finely polished, and its edges rounded, to prevent it from cutting the paper. The engraver works opposite to a window, having a screen interposed to soften the light, and the plate placed on an oblique table in the most convenient position for seeing.

Instruments.--The instruments employed in the practice of the art, are the following. 1. The graver. This is a small steel bar, of a prismatic form, having one end attached to an oblique handle, and the other ground off obliquely, so as to produce a sharp point at one angle. In working, this instrument is held in the palm of the hand, and pushed forward, so as to cut out a portion of the copper. 2. The dry point. This is a strong, bluntish needle, fixed in a handle, and intended for drawing the finer lines. It is held in the fingers, in the same way as a pen or pencil. 3. The scraper, a triangular instrument, with concave sides, and sharp edges, intended for removing or scraping off portions, which are accidentally raised above the surface. 4. The burnisher. This is merely a blunt, smooth tool, for rubbing out blemishes, and smoothing the surface of the copper. Various kinds of varnish, rosin, wax, charcoal, and mineral acids, are also employed in different parts of the operation, according to the subject and the style of engraving which is adopted.

Styles.--The principal varieties or styles of engraving on copper, are the following. 1. Line engraving. 2. Stippling. 3. Etching. 4. Mezzo tinto. 5. Aqua tinta. Lithography, and some other modes of multiplying designs, are imitations and substitutes, rather than species of engraving.[A]

Line Engraving.--Line engraving, called by the French, Gravure en taille douce, is one of the most common species of engraving; and though less elaborate than the second mode, has produced most of the finest and boldest specimens of the art. In this species, the surface and figures, the lights and shades, are produced by the multiplication of minute lines, cut in by the graver and dry point, approaching each other so nearly, that the inequality produced by the admixture of black and white does not offend the eye, nor interrupt the harmony of the piece. The effect and beauty of line engravings, depends much upon the smoothness of the lines, their gradual swell and decrease, and their evenness or parallel situation.

For engraving in this manner, the artist transfers the outlines of his original drawing, by tracing them with black lead, on an oiled paper,[B] and afterwards passing this paper through the press in contact with the copperplate, which is previously covered with a thin coating of wax. A sufficient quantity of the lead adheres to the copper, to enable him to engrave the outlines with great accuracy. The graver is then held in the palm of the hand, and pushed forward, with a strong but steady and regular motion, until a line is completed. The graver, by its operation, removes a thread of copper from the line, and at the same time raises the surface on each side of it, forming what is called a burr. This burr is subsequently removed by the process of scraping and burnishing. After the outlines are finished, the dark surfaces are introduced by means of close parallel lines cut in, in the same manner as before. Gradations of light and shade are produced by the gradual and simultaneous tapering of all the lines which constitute the dark portions; and the softness and regularity with which this is accomplished, greatly affects the beauty of the piece. Very dark shades are produced by lines crossing each other, either in squares or lozenges, which are varied according to the nature of the subject. Very light shades, on the contrary, are left untouched, or covered with broken lines. Lines which swell or taper, are first cut of a uniform size, and afterwards deepened by a second or third stroke of the graver. Mistakes or blemishes, are erased from the plate, either by burnishing with the proper instrument, or by rubbing with charcoal.

[A] Musical characters are sometimes executed in a mode different from all these, by making impressions with a punch upon pewter, or some other soft metal.

[B] Paper rendered transparent with spermaceti, is useful in tracing figures with a lead pencil. If paper be varnished with a mixture of Canada balsam and oil of turpentine, very distinct lines maybe traced on it with the dry point only, and these may be again transferred, by varnishing the copper, and tracing them upon it, through the paper. This method is now much employed by engravers.

Stippling.--The second mode of engraving, is that called stippling, or engraving in dots. This resembles the last mentioned method in its processes, except that instead of lines, it is finished by minute points or excavations in the copper. These punctures, when made with the dry point, are circular; when made with the graver, they are rhomboidal or triangular. The variations and progressive magnitude of these dots, give the whole effect to stippled engraving. This style of work, is always more slow, laborious, and of course more expensive, than engraving in lines. It has, however, some advantages in the softness and delicacy of its lights and shades, and approaches nearer to the effect of painting, than the preceding method. A more expeditious way of multiplying the dots, has been contrived in the instrument called a roulette, a toothed wheel, fixed to a handle, which, by being rolled forcibly along the copper, produces a row of indentations. This method, however, is less manageable than the other, and generally produces a stiff effect.

Etching.--Etching is the third mode of engraving, and is performed by chemical corrosion. It is apparently the easiest mode of engraving, requiring least practice in the operator. In fact, any person who can draw, may etch coarse designs tolerably well, after having acquainted himself with the theory only. Hence we find that engineers, naturalists, surgeons, &c, sometimes etch their own plates, especially of light subjects.

A plate for etching, is prepared in the same manner as for common engraving. It is then covered throughout its whole surface, with a very thin coating of varnish made of wax, mastic, and asphaltum; sometimes of rosin and animal oil, or of linseed oil inspissated by boiling. This varnish is blackened by the smoke of a lamp, in order that the operator may see the progress and state of his work. The instrument used in etching, is a needle, resembling the dry point, but of different sizes, according to the nature of the work. The plate being prepared, the operator, supporting his hand on a ruler, begins to make his drawing with the needle in the coat of varnish, taking care to penetrate always to the copper. In the use of the needle, those lines which require to be deepest, must have the greatest force bestowed on them, but it is not possible to produce so perfect an effect in this way, as by incisions of the graver. After the design is completed, the operator proceeds to the second part of the process, the corrosion, or, as it is technically called, biting in. For this purpose, the plate is surrounded with a wall of soft wax, to prevent the escape of fluid from its surface. A quantity of diluted nitric acid is then poured upon it, and suffered to remain for some time. A chemical action immediately takes place in all the lines or points where the copper is denuded by the strokes of the needle, while the rest of the surface is defended by the varnish. In the mean time, the operator brushes the surface frequently, with a feather, to clear away the bubbles and saturated portions of the metal. After the first biting is continued for a sufficient length of time in the judgement of the operator, the acid is poured off, and the plate examined. The light shades, if found sufficiently deep, are then covered with varnish, or, as it is technically called, stopped out, to protect them from further action of the acid. The biting is then continued for the second shades, which are next stopped out, and these processes are alternately repeated till the piece is finished. The plate is then freed from varnish, by melting and wiping it off, and cleansed by washing with oil of turpentine. It must, in this state, be carefully examined or proved, and any deficiencies in the lines, owing to the accidental presence of varnish, must be finished with the graver. The plate is then ready for the press.

The productions of the etching needle, can never have the smoothness and beauty of mechanical engravings. Notwithstanding all the care which may be taken, the lines will have an irregularity and roughness, owing to the unequal action of the acid. There are, nevertheless, subjects, to which this very irregularity renders etched work peculiarly suited. Those objects which in nature are rough and coarse, are well represented by this species of engraving. The trunks of trees, broken ground, rocks, walls, cottages, &c, especially when executed on a large scale, receive a more natural aspect from the rough effect of etching than they could do without great labor from the softer touches of the graver. In landscape engraving, we commonly find a mixture of methods, the coarser parts being etched, while objects of more delicacy are cut with the graver. Letters and written characters, are mostly cut, and but seldom etched.

Mezzo Tinto.--Engraving in mezzo tinto, or mezzotint, is the fourth species. This method is the reverse of all those hitherto mentioned, and consists in bringing up lights from a dark ground. The mezzo tinto was invented by Prince Rupert, in 1649. Since his time, it has been greatly improved, and though not calculated for general use, it has been applied to various subjects with great success. For engraving in mezzo tinto, the whole surface of the copperplate is first roughened, or covered with minute prominences and excavations, too small to be obvious to the naked eye; so that if a impression be taken from it in this state, it has a uniform velvety black appearance. This roughness is produced mechanically, by the operations of a small toothed instrument, denominated a cradle. This instrument, by continual turns and impressions, which occupy a great length of time, gradually breaks up and produces a uniform roughness on the whole surface of the plate. That the ground, as it is called, may be of the requisite fineness, the operation must be repeated a considerable number of times, the position of the plate in regard to the instrument, being varied each time. This is the most tedious part of the labor. When the plate is prepared, the rest of the process, to a skilful engraver, is easy, when compared with cutting or stippling. It consists in pressing down or rubbing out the roughness of the plate, by means of the burnisher and scraper, to the extent of the intended figure, obliterating the ground for lights, and leaving it for shades. Where a strong light is required, the whole ground is erased. For a medium light, it is moderately burnished, or partially erased. For the deepest shades, the ground is left entire. Care is taken to preserve the insensible gradations of light and shade upon which the effect and harmony of the piece essentially depend.

Engraving in mezzo tinto, approaches more nearly to the effect of oil paintings than any other species. It is well calculated for the representation of obscure pieces, such as night scenes, &c. Some individuals have applied it, with good success, to the engraving of portraits. The principal objection to the method is, that the plates wear out speedily under the press, and of course yield a comparatively small number of impressions.

Aqua Tinta.--Engraving in aqua tinta, is the only remaining mode. This is done by a process partly chemical, and partly mechanical. It consists in producing chemically, a rough ground, covering the surface of the figure to be engraved, and afterwards introducing the lights and shades by mechanical means. It may, however, be executed by a process wholly chemical. For engraving in aqua tint, the surface of the copper, after having the outline engraved or etched in the usual way, is covered throughout with minute particles of resin, invisible to the naked eye, detached from each other, and adhering to the surface of the metal. This process, called laying the ground, is effected in different ways. One method is, to enclose a quantity of finely-powdered rosin or mastic, in a flannel or linen bag. This is held at a certain height above the plate, and beat with a stick. A cloud of fine dust issues from the bag, and settles upon the surface of the plate, with the same uniformity as the dust of the atmosphere settles upon furniture in dry weather. This dust is fixed to the surface, by heating the plate till the resin melts. The ground is thus laid. A second mode is, to cover the plate with a coat of very thin spirit varnish, prepared for the purpose. This varnish is so fluid, or contains so little resin, that when it dries by the evaporation of the spirit, the whole surface breaks up, or cracks into an infinite number of particles, all adhering to the plate. After the ground is completed, the vacant parts of the plate, or those not intended to be occupied by the figure, are stopped out; i.e., covered by a thick varnish, impenetrable to acid. The plate is now surrounded by a wall of wax, as for etching, and diluted nitric acid is poured on. A chemical action immediately commences in all the interstices between the resinous particles; and the face of the plate, for the desired extent, is converted into a porous surface, made up of little prominences and excavations. The lighter shades are stopped out at an early stage of the process, and the corrosion continued for the dark ones. After the plate is judged to be sufficiently bitten in, it is cleaned, and proved by an impression. If the ground is good, i.e., not too faint, too coarse, or too uneven, the work is then finished by burnishing the shadings to give them greater softness, and, if necessary, by cutting deep lines or dots in the darkest parts.

Engraving in aqua tinta has the greatest resemblance to paintings in water colors, or in Indian ink. When well executed, the white points, which diversify the surface, are nearly invisible to the naked eye, so that a uniform surface is presented. The art was first invented by a Frenchman, by the name of Leprince, who for some time kept his art a secret, and sold his impressions for original drawings. It is a mode of engraving well adapted to light subjects, sketches, landscapes, &c., and for subjects of which only a few copies or impressions are wanted. Owing to the fineness of the ground, the plates wear out rapidly, and seldom yield, when of the ordinary strength, more than six hundred impressions.

Aqua tinta is the most precarious kind of engraving, and requires much experience and attention on the part of the artist, to succeed well. If the ground is laid too thick, or too thin, the result is imperfect. If the corrosion by the acid is not continued long enough, the ground is too faint; if continued too long, the acid acts laterally, and destroys the whole surface. It is often necessary to repeat the whole process, and to go through the operations of laying the ground, stopping out, and biting, a number of successive times, before a ground is obtained of sufficient strength and regularity to answer for the press.

Medallic Engraving. This beautiful art is supposed to have been invented in Philadelphia, by Mr. A. Spencer, prior to 1817. The object of this kind of engraving is, to give accurate representations of medals, coins, and bas-reliefs of a small size; and is effected by applying a machine to the surface of the medal, which will trace a line on the copper, corresponding exactly to the outline of the figure on the medal. Those who are familiar with a pantograph will be able to form an idea of this machine. It is so contrived, that, as it slides over the surface of the coin, every elevation or depression, which produces a perpendicular motion in the machine, causes at the same time a horizontal movement at the other extremity, which traces the line on the copper. Every time the machine passes over the coin, a single line is traced on the copper; and there is a delicately-contrived screw, by which the machine may be pushed forward after each line is drawn, so as to make the next line as near to it as the operator chooses. The effect is, to give an exact copy of the medal; and the drawing appears so salient, that we can hardly convince ourselves, at first, that we are looking upon a flat surface.

Copperplate Printing.--Copperplate printing is performed by means of a rolling press, in which the plate and paper are strongly compressed together between a cylinder of wood and a sliding platform. The ink employed for copperplates, is made of a carbonaceous substance, called Frankfort black, and linseed oil, inspissated by boiling. Oil must be used, instead of water, that the ink may not dry during the process; it is boiled till it becomes thick and viscid, that it may not spread upon the paper. Previously to the operation, the paper is wet, as for printing with types. The printer, having warmed his plate over a bed of coals, proceeds to cover its surface with ink by an instrument resembling a printer's roller. When the cavities of the engraving are thoroughly charged with ink, the smooth surface of the plate is wiped as clean from ink as possible. The latter part of the wiping is always performed by the palm of the hand, aided by a little dry powder, commonly whiting. The ink remains only in the crevices of the engraving, into which the hand does not penetrate in wiping the surface. The plate is next laid on the sliding plank, with its face upward, and the paper laid upon it. An elastic substance, commonly folds of woollen cloth, is placed above and below. A turn of the cylinder carries the plate under a very strong pressure, by which portions of the paper are forced down into all the cavities of the engraving. The ink, or a part of it, leaves the copper and adheres to the paper, giving an exact representation of the whole engraving.

Colored Engravings.--Colored engravings are variously executed. The most common are printed in black outline, and afterward painted separately in water colors. Sometimes a surface is produced by aqua tinta, or stippling, and different colors applied in printing to different parts, care being taken to wipe off the colors in opposite directions, that they may not interfere with each other. But the most perfect as well as elaborate productions, are those which are first printed in colors and afterwards painted by hand.

Steel Engraving.--The-process of steel engraving, introduced by Mr. Perkins, depends on the property, which steel has, of being softened, by losing a part of its carbon; and afterwards of being hardened, by regaining it. If a steel plate, prepared for engraving, be enclosed in a box with iron filings, and exposed to a white heat for some hours, the surface loses a portion of carbon, and becomes sufficiently softened to be cut with the graver. If then the plate, after being engraved, is reexposed to heat in a box with animal charcoal, the surface becomes again carbonated, and an engraved steel plate is thus obtained.

The great advantage of steel plates consists in their hardness, by which they last for an indefinite time, and yield an almost unlimited number of impressions; whereas a copperplate wears out after two or three thousand impressions, and even much sooner, if the engraving be fine. An engraving on a steel plate, may be transferred in relief to a softened steel cylinder, by pressure; and this cylinder, after being hardened, may again transfer the design, by rolling it upon a fresh steel plate; and thus the design may be multiplied at pleasure.

Steel engraving is of use, where a great number of impressions are called for; as it saves the expense of engraving the plate anew, and furnishes copies more exactly resembling each other, than can be obtained by any other mode. Of course, it affords the greatest security against counterfeiting.

Etching on steel plates, is practised with various chemical agents, one ot which consists of a mixture of six parts of acetic acid, with one of nitric acid. Another menstruum is made by dissolving an ounce of corrosive sublimate, and a quarter of an ounce of alum, in half a pint of water.

Wood Engraving.--Engravings in wood are differently executed from those already described, the subjects being cut in relief; so that they require to be printed in the same manner as common types, and not with the rolling press. The material used is boxwood, which unites the properties of hardness, fineness, and density. It is cut across the grain into pieces of the height of common types, in order that the engraving may be made upon the end of the grain, for the strength and durability. The surface being planed very smooth, the design is drawn upon it with a black-lead pencil. The lines of this design are left untouched, but the whole of the intermediate spaces between the lines are cut away with a common graver, or chisel. Wood engravings have the advantage that the blocks may be inserted in a page with common types, and printed without separate expense. They are exceedingly durable, and may, if desired, be multiplied by the process of stereotyping.

LITHOGRAPHY.

Lithography is the art of taking impressions from drawings or writings made on stone, without engraving.

Principles.--This art is founded on the property which stone possesses, of imbibing fluids by capillary attraction, and on the chemical repulsion which oil and water have for each other. A drawing is first made on stone, with an ink, or crayon, of an oily composition, and the surface is washed over with water, which sinks into all the parts of the stone, not defended by the drawing. A cylindrical roller, charged with printing ink, is then passed over the surface of the stone. The drawing receives the ink, which is oily, while the other parts of the stone repel it, being defended by the water. The process, therefore, depends entirely on chemical principles, and is thus distinct from letter-press or copperplate printing, which are mechanical. On this account, it has, in Germany, been called chemical printing.

Origin.--The invention of lithography is generally ascribed to Alois Senefelder, the son of a performer at the Theatre of Munich, who received his education at the University of Ingoldstadt. Having become an author, and being too poor to publish his works, he tried many plans with copperplates, and compositions, and accidentally with stone, as substitutes for letter-press, in order to be his own printer. His first essays to print for publication, were some pieces of music, executed in 1796, after which he attempted various drawings and writings. The first productions of the art were rude and of little promise. Its progress, however, has been so rapid, that it now gives employment to a vast number of artists, and works are produced which rival the finest engravings, and even surpass them in the expression of certain subjects.

Lithographic Stones.--As calcareous stones will all imbibe oil and water, and receive the action of acids, they are all capable of being used for lithography. Those, however, are best adapted to the purpose, which are compact, of a fine and equal grain, and free from veins, or imbedded fossils or crystals. A conchoidal fracture is considered a good characteristic.

The quarries of Solenhofen near Pappenheim, in Bavaria, furnished the first plates, and none have as yet been found to equal them in quality. They are of a uniform, pale yellowish or bluish white color, and the fracture is perfectly conchoidal. Generally, the hardest are considered best, provided they are uniform in texture. Such are necessary for fine chalk drawings, while softer ones answer for ink, or for coarser drawings in chalk.

In France, stones have been found near Chateauroux, of a similar color to those of Solenhofen, and even harder, and of a finer grain, but they are full of spots of a softer nature, so that it is difficult to procure pieces of the necessary size. In England, a stone has been used for lithography, which is found at Corston, near Bath. It is one of the white lias beds, but not so fine in grain, nor so close in texture as the German stone, and therefore inferior. In the extensive limestone tracts of the United States, there is little doubt that future observation will bring to light stones of a suitable character for lithography.

To bear the pressure used in taking impressions, a stone twelve inches square, should be an inch or two thick; and the thickness must increase with the size of the stone.

Preparation.--The stones are first ground to a level surface, by rubbing two of them face to face with sand and water. To prepare them for ink drawings, they are next polished with pumice-stone. But when they are intended for chalk drawings, they are merely ground with fine sand, which has been passed through a sieve, and which produces a smooth and uniform surface, which is grained and not polished, this surface being best adapted for holding the chalk.

Lithographic Ink and Chalk.--For these materials, the union of several qualities is required, to obtain which, it is necessary to combine several substances together.

For lithographic ink, a great many different receipts have been given, one of the most approved of which is, a composition made of equal parts of tallow, wax, shell lac, and common soap, with about one twentieth part of the whole, of lampblack. These materials are mixed in an iron vessel. The wax and tallow are first put in, and heated till they take fire, after which, the other ingredients are successively added. The burning is allowed to continue until the composition is reduced about one third.

Lithographic chalk should have the qualities of a good drawing crayon; it should be even in texture, and carry a good point. The following proportions are among the best. Soap, 1-1/2 oz.; tallow, 2 oz.; wax, 1-1/2 oz.; shell lac, 1 oz.; lampblack, 1/4 oz. The manipulation is similar to that for the ink.

Mode of Drawing.--With these materials, the artist proceeds to work on the prepared stone, after wiping it with a dry cloth. The ink being rubbed with warm water, like Indian ink, is used on the polished stone, and a gradation of tints can be obtained, only by varying the thickness of the lines, and the distance at which they are placed apart. It is necessary to mix the ink to such a consistency, that, while it works freely, it shall yet be strong enough to stand perfect, through the process of printing. A consistency, a little greater than that of writing ink, is sufficient for this purpose. The instruments used for drawing with ink, are steel pens, and fine camel's hair pencils.

The chalk will not hold upon the polished stone. But the grained stone, prepared for chalk, may be drawn upon with the chalk crayon, as easily as paper. The subject may be traced on the stone, with lead pencil or red chalk, but it should be done so lightly, as not to fill up any of the grain of the stone. In drawing, the degree of pressure of the hand will vary the strength of the tint, and it is desirable to give the requisite strength at once, as the surface of the stone is a little altered, by receiving the chalk, and hence it does not take any additional lines with the same equality. Practice is necessary to give a command of the material, as it does not work quite like the common crayon, there being great difficulty in keeping a good point. There is also difficulty in obtaining the finer tints perfect in the impression; and for the light tints, the chalk must be used in a reed, as the metal port-crayon is too heavy to draw them, even without any pressure from the hand. A scraper is used to correct errors, and also to produce lights.

It is necessary to observe that the grain with which the stone is prepared, should vary with the fineness of the drawing. Several pieces of chalk should be prepared to use in succession, as the warmth of the hand softens it. It is useful to cut the chalk to the form of a wedge, rather than a point, as it is less likely to bend, in that form. Small portions of the point will break oft during the drawing; these must be carefully removed with a small brush.

Etching the Stone.--After the drawing is finished on the stone, as before described, it is sent to the lithographic printer, who proceeds to etch the drawing, as it is called. The stone is placed obliquely on one edge over a trough, and very dilute nitric or sulphuric acid is poured over it. The degree of strength, which is little more than one per cent, of acid, should be such as to produce a very slight effervescence. The object of this slight etching appears to be to produce a chemical, rather than a mechanical change of surface, and it is by some considered superfluous, except to discharge the alkali of the soap.

The stone is now carefully washed, by pouring clean rain-water over it, and afterwards gum-water; and when not too wet, the roller, charged with printing ink, is rolled over it in both directions, till the drawing takes the ink. It is then well covered with a solution of gum-arabic in water, of about the consistency of oil. This is allowed to dry, and preserves the drawing from any alteration, as the lines cannot spread, in consequence of the pores of the stone being filled with gum.

Printing.--When the stone is ready for the press, the printing ink is applied to it, by means of an elastic roller, covered with leather. In the lithographic press, the paper is first brought in contact with the stone, and protected by a tight cover of strong leather. The whole is then passed under the edge of a blunt wooden scraper, which is powerfully pressed down by a double lever, and thus every part of the paper is successively brought into forcible contact with the stone, and an accurate impression received of the drawing. The ink is then reapplied to the stone, and the process repeated for each impression.

Printing Ink.--This is composed, as other printing inks are, of oil-varnish, and fine lampblack. To prepare the varnish, a vessel is about half filled with pure linseed oil, and heated till it takes fire from the flame of a piece of burning paper. It should then be allowed to burn, till it is reduced to the degree of density required.

Remarks.--The great distinction of lithography from engraving is, that it gives a facsimile of the original drawing, which retains the freedom and touch of the artist's own hand, while, on the contrary, an engraving must be a copy. This character in a lithographic print, arises from the facility with which the drawing is produced, as the process is exactly that which the artist would follow, in making a common drawing. A further advantage, derived from the same cause, is, that the drawing being made at once on the stone, the whole expense of engraving is saved.

The more finished drawings in ink, however, have not the same advantages; for the gradations can only be obtained by the variations in the breadth and the distance of the lines, which is the same principle as that on which the engraver works; and hence the labor is more nearly equal in the two methods. The number of impressions, which can be taken from a lithographic chalk drawing, will vary according to the fineness of the tints. A fine drawing, will give four hundred, or five hundred; a strong one, one thousand, or one thousand five hundred. Ink drawings, and writings, give considerably more than copperplates. The finest will yield six thousand, or eight thousand; and strong lines, and writings, many more. Upwards of eighty thousand impressions have been taken at Munich, from one writing, of a form for regimental returns.

A method has been introduced, by which copies of valuable engravings may be multiplied indefinitely. An impression on paper is taken, in the usual manner, from the copperplate, and immediately laid with its surface upon water. When sufficiently wet, it is carefully applied to the surface of a stone, prepared in the usual manner, and pressed down upon it by the application of a roller, till the ink leaves the paper, and adheres to the stone. It is then printed in the common way. Autographic writings may be transferred from paper to stone, and printed in a manner nearly similar.

A common printed page, being originally made with an oily ink, is capable of being transferred to stone, by softening it with a chemical solvent and passing it through the press in contact with the stone. Copies can thus be indefinitely multiplied.

WORKS OF REFERENCE.--LANDSEER'S Lectures on Engraving, 8vo. London, 1807;--MEADOWS'S Lectures on Engraving, London, 1811;--PARTINGTON'S Mechanic's Gallery, 8vo. 1825;--REES'S Cyclopaedia, under the various heads;---HULMANDEL'S Treatise on Lithography, 8vo. 1817;--SENEFEILDER'S Complete Course of Lithography, 4to.;--London Journal of Arts, passim;--DE LASTEYRIE, Journal de Connaisances usuelles, translated, Franklin Journal, vol. iv.;--North American Review, 1834.