First edition. McLean (Victorian Book Design, pp. 26-28) reproduces as a full-page plate the portrait of Byron and also shows four other "distorted" portraits to show the possible uses of the Collas process. He states "In 1838 Tilt published Authors of England containing fourteen portraits, after medallions by H. Weekes and E.W. Wyon, engraved on steel by Achille Collas's patent process, a curiosity perhaps, but the skill of the technique is breath-taking. The process, known as `anaglyptography' was one of several in which a tracing arm, moving over a rounded object, such as a plaster cast of a medal, could produce by mechanical means an engraving which had an uncanny appearance of being embossed." Wakeman (Victorian Illustration, p. 31) states "The French machine was built by Achille Collas and used in England for the plates of The Great Seals of England (Hering, 1837) and H.F. Chorley's The Authors of England (1838). Some copies of the latter have an account of the process and its invention bound up at the back." With the pictorial title and all 15 plates present. With the bookplate and pencil signature of Gavin Bridson. Covers faded. Foxing. New endpapers.