GLASS-MAKING. 19 



and of effective changeableness. These considerations are attract- 

 ing the attention of artistic people, and probably in no other field 

 is there better work being done to-day. It is true that the mate- 

 rial is fragile — very fragile — but then few works of art are fash- 

 ioned with the idea of rough usage. If protected from mere 

 mechanical injury, glass will outlast many forms of matter appar- 

 ently much more robust. Particularly is it proof against that 

 ever-present enemy, the atmosphere. Stone crumbles and decays, 

 metals corrode, and pigments fade, but glass defies nearly every- 

 thing but fracture. The few glass ornaments that have come 

 down to us from the ancient world are in a state of superior pres- 

 ervation. Glass and terra-cotta, fragile as they are, seem better 

 adapted than even tablets of stone for preserving the records of 

 the past. Clay cylinders from Assyria, depicting the story of the 

 garden of Eden, are a part of historical record still extant : the 

 graven decalogue is no more. 



The subject of picture - windows is a very large one, since 

 their fabrication demands the exercise of such diverse faculties. 

 Viewed from either the artist's or the technologist's standpoint, 

 it presents many features of interest. In our nomenclature we 

 have permitted ourselves to fall into rather careless habits. The 

 terms "painted," "stained," and "mosaic" glass are used indis- 

 criminately to designate any form of window-glass work which 

 involves color, but a moment's consideration will show them to 

 be far from synonymous. Some of our best effects are produced 

 without the use of either paint or stain, and such windows have 

 the advantage of a much greater durability. In painted glass the 

 colors are produced by enamels fused to the surface of the glass 

 by means of heat. In stained glass, a permanent transparent color 

 effect is secured by the action of heat on certain metallic oxides 

 applied to the surface as pigments ; while in mosaic glass, pure 

 and simple, the design is brought out by the use of shaped frag- 

 ments of colored glass bound together by strips of doubly grooved 

 lead. 



The three products, it will be seen, are quite distinct. It fre- 

 quently happens, and in the older examples of ecclesiastical design 

 it is nearly always the case, that all are combined in one window. 

 But at the present time there is a strong reaction against the em- 

 ployment of either paint or stain, since they are not only less 

 durable but also less brilliant than homogeneous colored glass. 

 There is a decided tendency to rely entirely upon the mosaic 

 treatment, and to limit the use of paint to the representation of 

 the human figure. 



The manufacture of mosaic glass has attracted the attention of 

 men of such ingenuity and taste that it deserves its rank among 

 the fine arts. It has attained a degree of artistic perfection of 



