MEZZOTINT  . During the 19th

century two revolutions occurred in the British art of mezzotinto engraving—" la maniere anglaise." The original defect of the method was the incapacity of the mezzotint " burr " on copper to yield as many fine impressions as other forms of engraving . To this defect was attributable the introduction, in 1823, of steel instead of the soft copper previously used— a change which, with the endeavour to avoid technical difficulties, led to the " mixed style," or combination of mezzotint with etching, and a general departure from the traditional form of the art, " pure mezzotint " on copper . The affinity of the method to painting in black and white which differentiates it from other kinds of engraving, and was the distinguishing charm of the mezzotints of the 17th and 18th centuries, was for a time lost, but a revival of pure mezzotint on 352 copper, beginning in 188o—a return, in fact, to the mode in which the classics of the art were engraved in the time of Sir Joshua Rey nolds—was made possible by the invention of steel-facing . By this process engraved copper plates are electroplated with a film of steel, renewable when worn in course of printing; and a mezzotint on copper, so protected, yields more fine impressions than if it had been engraved on steel, whilst the painter-like quality remains unimpaired . In " pure mezzotint " the design is evolved from dark to light entirely by scraping away more or less of the previously laid " ground," the original " burr " of which is left untouched in the extreme darks, and no acid, etching or line-work is used in it at all . The usual short descriptions of the method are misleading, because they fail to explain that it is the " ground," and not the burr " of it only, which is scraped away in greater or smaller degree to produce the varying tones of the design . The necessity of realizing that there are two constituents of the " ground," the " burr " and the indentations out of which the " burr " is raised, will be appreciated later . The " rocking-tool," with which the " ground " is laid, somewhat resembles a carpenter's chisel, but the blade is 3 in. wide and only about 24 in. long, whilst the cutting edge, instead of being straight, is curved in the segment of a circle . One side of the blade is deeply engraved with lines from edge to handle, and the ridges which remain between these lines form teeth at the cutting edge when the unengraved side of the tool is bevelled as an ordinary chisel is sharpened . The tools contain from 35 to 120 teeth to each inch of their width, those with the most teeth producing grounds of the finest texture . The operator rocks the curved edge of the tool from side to side on the bare copper plate, causing the tool to travel forward, whilst each tooth makes an indentation in the copper and throws up a corresponding particle of metal, which is called the " burr." When the whole plate has been so rocked across in 45 to 6o different directions, so that no visible speck of the original bright copper surface remains unfretted by the teeth of the " rocking-tool," the " ground " is termed " full " and is ready for scraping the design .

The innumerable particles of copper forming the raised " burr " give to a " full ground " much the

appearance of copper-coloured plush, and a print from it, taken before any scraping has been done on it, looks not unlike a piece of black velvet . The lights and semi-tones of the design are produced by subsequent scraping and burnishing . Assuming that a mezzotint is to be scraped from a lady's portrait by Sir Joshua Reynolds in which a piece of black drapery crosses a white dress--the engraver begins to work on a previously laid " ground " which would print uniformly black before scraping commences . In the extreme darks of the black drapery the raised " burr " is left untouched by the " scraper "—a two-edged steel instrument resembling an ancient Roman sword-blade in miniature, but having a longer point . Working from dark to light, the engraver produces the varying tones of the folds of the black drapery by scraping the raised " burr " down more or less, lowering it in fact so that it will not hold so much ink as where it is left untouched in the extreme darks . In the highest lights of the black drapery all the raised " burr " will have been removed and the original surface of the plate reached, but as yet the engraver has not produced any tone lighter than middle tint (although he has completely modelled up the black drapery), because the indentations out of which the " burr " was raised still remain in the plate and hold ink in printing . In order to produce the infinite gradation of delicate tones in the white dress, or in a sky, the scraping is continued, the indentations being thus made shallower in the passages scraped, and therefore less capable of holding ink, whilst they are obliterated almost entirely in the highest lights . When the mezzotint is finished the black drapery will stand higher than the surface of the plate modelled in a relief composed of the raised " burr," whilst all the tones of the white dress, from middle tint to pure white, will be so many actual depressions in the plate, the highest lights being the deepest . The speck of light in the eye, for instance, is a pit in the plate, surrounded by a tract of more or less raised " burr," which provides the intense black of the pupil and the half-tints of the iris . The difference of surface levels is very appreciable where high-lights impinge on strong darks, but it exists in varying degree all over the plate, and the greatest technical difficulty in pure mezzotint is to obtain adequate " edge " and definition, because the tendency is to remove too much " ground " from the edges of adjacent darks in the course of the constant scrapings necessary to smooth and polish the depressed lights . In printing a mezzotint a non-fluid. ink is thoroughly worked into every part of the plate, and the superfluities wiped off again, leaving as much ink as possible in the darks, the raised " burr." If the bottom of the small lights is not quite smooth, the ink sticks in the roughness and they print dark instead of light, or the printer has to wipe so hard to get the ink out of the depressed lights that he removes too much from the raised darks . In either case loss of definition and contrast of effect results .

This inherent difficulty of scraping to a

sharp edge caused the use of the " mixed " methods.in which the details were sharpened by outlining them with stipple or line etching . Mezzotint is the best form of engraving for completeness of representation, but etching is better adapted for sketching from nature or for the expression of any fleeting idea . The two arts have distinct uses and limitations . The art function pf true etching as practised by Rembrandt lies in economy of expressive line to suggest the artist's meaning, and that of mezzotint in completion of tonality to explain it . Artistic suggestion, which is not inherent in the solid tones of mezzotint, has to be imparted to the work entirely by the free play of the " scraper " on the " ground," much as the painter attains it on canvas with the brush . The first reputed mezzotint was produced at Amsterdam in 1643 by Ludwig von Siegen, an officer in the service of the Land-grave of Hesse, and an amateur artist; but the work History. was a direct drawing on copper with an instrument of comparative precision resembling the roulette rather than a mezzo-tint, ground laid with the rocking-tool and scraped from dark to light in the present manner of the art . Siegen's innovation was led up to by the previous stipple work of Giulio Campagnola and Janus Lutma; the roulette appears to have been used before his time; and though he shared in the evolution of the rocking-tool, he was not the sole inventor of it . The earliest works referable to the method at the print room of the British Museum afford evidence; though inconclusive, that Prince Rupert, to whom Siegen showed his mode of work in 1654, and possibly also their common friend, Th . Caspar von Fiirstenberger, and Rupert's assistant, Vallerant Vaillant, were more or less concerned in the gradual development of mezzotint engraving . The rocking-tool was apparently improved by Abraham Blooteling, a Dutch painter and engraver of •fine portrait mezzotints, who worked in Holland and in England about the year 1680 . Rupert brought the new art over to England at the Restoration, and the portrait of Charles II., dated 1669, by William Sherwin, the first English mezzotinter, bears the engraver's acknowledgment of his indebtedness to Rupert for the secrets of the method . Mezzo-tint continued to be practised for a while on the Continent, but the successors of Sherwin in England so excelled in it that it early acquired abroad the title of " la maniere Anglaise," and has since become an exclusively British art .

Though used for transcribing the subject-pictures of the

great Italian masters, and of Rembrandt, Vandyck and Rubens, almost every kind of subject being later engraved in it, the staple production in mezzotint has always been the portrait . Until the middle of the 18th century the tools continued somewhat archaic, causing in the prints an appearance of warp and woof, like that of ill-woven material, which detracted from reality of representation . The coarseness and unequal depth of the " grounds " offered so much resistance to freedom of execution with the " scraper " that, though the early engravers were quite as good artists as their successors, painter-like touch was not conspicuous in the work until M'Ardell and the interpreters of Sir Joshua Reynolds had improved the tools and technique . Except for the collector, therefore, the chief attraction in the prints of F . Place and Luttrell, Beckett and Williams, and later those of John Simon, John Smith and John Faber, jun., who were the principal exponents of mezzotint in the last years of the seventeenth and first half of the eighteenth centuries, lies in their long series of portraits after Vandyck, Lely, Kneller and the Dutch painters then practising in England, representing such interesting personages as Charles II. and Nell Gwynn, Addison and Pope, Congreve and Wycherley, Locke and the great duke of Marlborough . The classics of mezzotint engraving are to be found amongst the best plates after Sir Joshua Reynolds by James M'Ardell, J . R . Smith and Valentine Green, the Watsons, Dickinson, Fisher, Dixon and some others, who worked during the last half of the 18th century . The brushwork of Reynolds was more in harmony with the mezzotint method than the slighter painting technique of Gainsborough and Romney, who were much less frequently en-graved, perhaps because it is the highest technical difficulty in mezzotint to render the sharp edges of a sketch . For this reason a typical Gainsborough was never successfully engraved in the method . Though professional publishers and printers existed at this time and earlier, the word " excudit " on an old print, implying " published," not " engraved," the authors of the " Sir Joshua " mezzotints in most cases printed, published and sold their own works, and pure mezzotint, unmixed with etching, was almost exclusively the method they employed . Mezzotints were occasion-ally printed in colours, notably those engraved later after George Morland, the primary object being to conceal the worn-out condition of the plates .

The departure from pure mezzotint and temporary decay of the art began when, towards the end of the 18th century,

Richard Earlom, otherwise a fine artist in the traditional method, notably in translations of Vandyck and Wright of Derby, began to outline the details of his plates with stipple etching in order to avoid the labour and difficulty of scraping them to a sharp edge, using the " ground " alone . Earlom, however, did not destroy the mystery of the rich velvety darks by etching into them . A demand then arose for larger editions than the soft copper plates would yield, and the engravers attempted to meet it by combining mezzotint with positive line-etching throughout the work, thus shortening the labour of scraping the details, and fortifying the darks with lines sunk below the surface of the plate . The harmony of line and tone in some of the prints in this style by S . W . Reynolds and Charles Turner, after Sir Joshua, Hoppner and their contemporaries, was more convincing than the later " mixed style " of Samuel Cousins, because there was a certain artistic significance in the etched line itself apart from the mezzotint tone, but every touch of line in a mezzotint does something to destroy the painter-like quality, and a decadence was in progress . The same mixed method on copper was used by J . W . M . Turner in his Liber Studiorum series of landscape plates, his object being to rival the pen-and-wash drawings of Claude's Liber Veritatis . Turner, however, was not so practised in etching or mezzotint as the engravers before mentioned, and the etched foundation of the Liber plates was too strong for the mezzotint tone, destroying the breadth of the light, the richness of the darks, and the artistic " keeping of the whole effect . It is the grand design of Turner reflected in the plates, rather than any quality of mezzotint or etching in them, which appeals to the artist and the connoisseur .

Perhaps the greatest success in harmonizing line and tone in one plate was achieved by

David Lucas in his " English Landscape " series of mezzotint after John Constable, in which he sharpened his details with the roulette, or with a slight line put in with the point of the scraper as scraping proceeded, retaining the pure " burr " in his darks . Lucas, like Samuel Cousins and his contemporaries, was handicapped by being compelled to work on the steel plates introduced in 1823, and this was the cause of the chief defect of his plates, the excessive opposition of black and white . The warm general tone which assisted the picturesqueness of the 18th century mezzotints was lost by the use of steel, because the ink did not cling to it as it does to the more porous copper . Steel being harder than copper, the rocking-tool penetrated less deeply, raising less " burr," and the consequent loss of force in the darks necessitated the scraping up of the lights to a higher key to force contrast of effect, which was also enhanced by the use of very white paper and a coarse black ink . It was soon found that the unfortified " burr," even on steel, would not yield the constantly increasing numbers of impressions demanded . The labour of scraping sharp lights was greatly enhanced, and though some pure mezzotints were engraved on steel, painter-like touch was practically unattainable on it, and the general effect was cold and uninteresting . The early work of Samuel Cousins after Lawrence in the comparatively pure method, and the final development of the " mixed style " on steel in his later plates after Reynolds, Millais and Land-seer, are referred to in the article on Samuel Cousins . For nearly forty years pure mezzotint ceased to be practised altogether, and the revival of it, which began in 188o, was led up to by the invention of steel-facing . The competition of photo-gravure, which steel-facing made a commercial possibility, for a time checked the new movement, but a photogravure, despite a mere surface resemblance to a mezzotint, is a photograph manipulated to imitate an engraving, entirely devoid of artistic individuality . In 1898 for the first time a Society of Mezzotint Engravers was formed to foster the art .