44 PROCEEDINGS OF THE NATIONAL, MUSEUM. vol. 60. 



the product gave it value for ornamental purposes. Scenes illus- 

 trating glass blowing are sculptured on the walls of ancient Egyptian 

 tombs. Other eastern peoples practiced the art with surprising 

 skill at an early date. It is difficult to secure specimens to illustrate 

 either the steps of progress in glassmaking or the articles produced 

 by the various nations. Strangely enough it can not be said that 

 the moderns have advanced beyond the ancients in the art of working 

 in glass, save perhaps in the invention of mechanical devices for 

 shaping and in expansion of use. It is a question whether we are 

 able to imitate some forms of their work. There really are no primi- 

 tive steps in this art, since culture must have been well advanced 

 before the properties of the materials were discovered or the neces- 

 sary processes developed. 



No. 1. Volcanic glass — obsidian. Natural product. 



No. 2. Furnace slag — glass. Accidental product of such as may have suggested 

 use of glass. 



No. 3. Glass ornament ; head of hairpin ; Bronze Age. Europe 101,341 



No. 4. Ancient Roman glass; toilet bottle 101,906 



No. 5. Ancient Roman glass; toilet bottle 95,840 



No. 6. Modern glass ; American ; Tiffany 96, 446 



No. 7. Modern glass; American; Tiffany 96,438 



No. S. Modern glass ; American ; Tiffany. 



SEKIES 5. — ENAMEL. 



Plate 49. 



The discovery of processes by means of which glassy compounds 

 could be produced on or applied to the surface of earthenware by 

 the aid of fusion opened new fields to the worker in clay and the 

 decorator of metal. When the glassy substance is distributed in a 

 more or less transparent film over the surface of objects treated, it is 

 usually classed as glaze, but when rendered opaque by the addition 

 of color, and especially when applied in thick bodies as decoration, 

 it is known as enamel. As applied to metal surfaces there are three 

 well-marked varieties — surface enamel, champleve enamel, and cloi- 

 sonne enamel. In the first vase (No. 1) the colored glass is applied 

 to the plain metal surface; in the second vase (No. 2) it fills in de- 

 signs excavated in the surface of the metal; and in third vase (No. 

 3) the design is outlined by metal wire fixed to the surface and then 

 filled with colored glass. Five successive stages in the progress 

 of the latter work are shown. 



No. 1. Vase; porcelain with lacquer — cloisonne decoration. 



No. 2. Vase ; enamel on metal. China. 



No. 3. Five successive stages in the cloisonne process. Japan. 



HISTORY OF SCULPTURE. 



The term sculpture is here applied to the whole range of processes 

 and products pertaining to the shaping of stone, but is not extended 



