GLASS PAINTING GLASS SNAKE beeswax, or other suitable substance. The sheet of colorless glass, with the pieces thus ar- ranged adhering to it, is placed upon an easel, and the shadows of the picture are put on with the same material as that used in tracing the outlines. The shading, however, is not traced from the cartoon, as were the outlines, but is done by the skill and experience of the painter. When the shading is completed, and the tints of yellow, if any are required, are put on, the pieces of glass are detached from the colorless sheet and again subjected to heat, for the pur- pose of " burning in " the shadows. If more work by the painter is required, the process is repeated, the glass being thus subjected to heat in some instances six or seven times. The work of the painter being completed, the fin- ished pieces are taken by the "leader," who, having arranged them by the aid of the " cut- ting drawing" so as to form the entire design, fastens them together by means of strips of grooved lead skilfully fitted around the edges of the several pieces. If the window is a largo one, as is generally the case, it is divided into parts of convenient size, which are fitted to- gether when the window is put in its place. Bars of iron are also sometimes placed across the window at the line of junction and at other convenient intervals. This general process of producing mosaic stained glass windows has been in use from the earliest times, though it may have been modified in some of its details; and until some other method of imparting colors to glass without detracting from its transparency and brilliancy is discovered, the opaque lead lines in the design must be accept- ed as a necessity. In his "Art of Glass Paint- ing," Mr. 0. Winston says: "The necessity of leading :i glass painting together is one of those conditions which cannot be evaded by any ingenuity. The lead work and saddle bars must be accepted as necessary parts of the composition. The design must be made with reference to them, and that glass painting must be acknowledged to be the best which admits of the leads being thrown into the outlines, and made to serve as outlines ; and which by the simplicity, I might almost say roughness, of its design and execution, prevents the harsh- ness of the saddle bars from being obtrusive. In this respect the glass paintings prior to 1560, and until the 18th century, must be considered superior to those later works in which the at- tempt has been made to ignore the leads and saddle bars, by leading the work together in squares independently of the outlines of the composition, or by twisting the saddle bars so as to avoid their cutting the design at regular intervals; because both methods immediately suggest the idea of a blemished picture, and make us immediately perceive how much bet- ter the work would be without loads or saddle bars.. But a window cannot be constructed without them; hence it is better to adopt them us essential parts of the design; and the beautiful windows of the choir of this [Lich- field] cathedral, which bear date between 1632 and 1589, show that a design so constituted is compatible with high pictorial effect." An- other condition which must be particularly ob- served is the preservation of transparency in the highest degree consistent with the pro- duction of a picture. For this purpose the high lights of the window must be as free from shading as possible. Indeed, light shading throughout the entire design is one of the con- ditions imposed by the nature of the material. These conditions were fully recognized by the artists of the middle of the IGth century, and this fact accounts largely for the superiority of their productions to those of their prede- cessors. In the best glass paintings of that pe- riod there is always an abundance of light in the upper portion of the window, while in the choice of subjects and their general treatment the artist selected those that could be made the most effective with the least shading. Among numerous works on this subject are : Lasteyrie, Histoire de la peinture sur verre d^apres des monument en France (2 vols., Paris, 1838-'5G); Gessert, OescMcJite der Glasmalerei (Stuttgart, 1889); Ballantino, "Treatise on Painted Glass " (London and Edinburgh, 1845) ; Bontemps, Peinture sur verre au dix-neu- vieme si&cle (Paris, 1845) ; Weale, " Ancient Painted and Stained Glass" (London, 1846); Winston, "Inquiry into the Difference of Style observable in Ancient Glass Paintings, especially in England, with Hints on Glass Painting" (London, 1847), and "An Introduc- tion to the Study of Painted Glass" (Oxford, 1849); Warrington, " History of Stained Glass " (London, 1848); Fromberg, "An Essay on the Art of Painting on Glass" (London, 1851); Bielfeld, " A Guide to Painting on Glass " (Lon- don, 1856); and Winston, "Memoirs illustra- tive of the Art of Glass Painting" (1865). GLASS SNAKE (ophisaurus ventralis, Daud.), a North American reptile, improperly called a snake, belonging to the order sauropJiidia of Gray, and to the chalcidian or cyclosaurian Glass Snake (Ophisaurus vcn trails). family of saurians of Dum6ril and Bibron. The head is lizard-like, sub-oval, with rounded snout, covered above with numerous polygonal plates, largo anteriorly, the frontal the largest;
