When mezzotint engraving was first introduced into England, the famous artists, Reynolds and Gainsborough, had reached the summit of their fame. The time was indeed auspicious. Line engraving failed to give a faithful reproduction of the peculiar style of painting then so much admired, while mezzotint engraving, with its soft gradations and attractive qualities of expression, translated with a vivacity and facility that could not fail to please and satisfy. Then, again, a somewhat abrupt change manifested itself in the pictorial art of this period. Representations of incidents and portraits of famous personages, which were in themselves interesting, took the place of the severely artistic productions of the past. The natural result was an intense interest, which embraced the art and the process by which it was popularised. =Description.=--The mezzotint process of engraving may be described in a very few sentences. The plate of metal is first covered with a ground or _tone_. To accomplish this, a tool with a serrated edge is passed over the surface in various directions. The myriads of microscopic indentations thus produced constitute a _tooth_ or roughness similar to the grain of a coarse sandstone. This grain holds a certain proportion of printing ink, and gives a rich, velvety black impression. On such a ground the engraver works up his design, and, by the skilful use of scraper and burnisher, obtains a series of tones or almost imperceptible gradations. He removes just so much of the grain as may be required for the lighter tones, and by burnishing or polishing, after the scraper has been used, secures the high lights. In one respect, at least, this form of reproductive art is peculiar, and unlike any other types of engraving. The artist works from black to white, and produces, on the plate, the lights instead of the shadows. =Artistic Qualities.=--Although capable of most charming effects, the mezzotint process never became a really serious menace to line engraving, with its firm and expressive outlines and peculiarly lustrous textures. Yet it is not at all surprising that a process, offering the artistic qualities of reproduction which mezzotint possesses, should prove successful in the interpretation of such light and shade as, for example, Turner painted into his pictures. Turner was engaged upon the series of pictures for his _Liber Studiorum_ when he suddenly realised the value of mezzotint engraving. He consulted with Charles Turner, an eminent engraver, who afterwards executed twenty-three of the _Liber Studiorum_ plates, and eventually decided to adopt a combination of etching with mezzotint for the reproduction of that famous series of pictures. The leading or essential lines of each picture were etched, probably by Turner himself, and the mezzotint added by other engravers.