GLASS-MAKING, i 75 



lieved that the vase was made of onyx, and described it as a most 

 interesting cameo. It is now known to be made of glass composed 

 of two layers. 



The Portland vase was a hint to the glass-makers, and one 

 that they made good use of. In the most elaborate examples of 

 the modern product three colors are employed, and the effect, if 

 the material has been judiciously managed, is exceedingly beau- 

 tiful. 



A vase is the best type of the cameo glass, since the function 

 of the ware is almost wholly decorative. From beginning to end 

 the process is one of great ingenuity. The basis of the vase is 

 commonly of opalescent glass — that is, glass made opaque by the 

 presence of some finely ground but insoluble oxide, or some such 

 mineral as cryolite or fluor-spar. A lump of this glass is gathered 

 on the end of the blowpipe and formed into a symmetrical shape 

 by rolling on the marvering-table. It is then dipped at short in- 

 tervals into two baths of molten glass of the colors desired. The 

 composite lump is fashioned into shape by means of those various 

 manipulations which the glass-blowers perform so adroitly. This 

 gives a vase made up of three distinct layers of different colors. 

 Its subsequent treatment is both chemical and mechanical. The 

 design is painted on the glass by hand, or else transferred with 

 special care from freshly printed paper, as in the case of the 

 etched globes. The vase is then dipped into the bath of hydro- 

 fluoric acid and allowed to remain until both of the outer colors 

 on the exposed portions are eaten off. It is now taken out, the 

 ink washed off, and its subsequent treatment intrusted to the en- 

 graver. At this stage of the process only two out of the three 

 colors are plainly visible, the intermediate one being seen simply 

 as a colored line between the other two surfaces. By means of 

 the engraving-wheel the outline of the design is made more clear 

 cut, and enough of the outer layer removed to show the interme- 

 diate color as a delicate shading. An immense amount of work 

 can thus be put upon a comparatively small article, and the cost 

 meanwhile grows in proportion. Single pieces have been manu- 

 factured in England valued as high as two thousand dollars. 



In spite of its great beauty and ingenuity, however, it is an 

 undeniable fact that the cameo glass is losing rather than gain- 

 ing in favor with the buying public. Some of the establishments 

 which formerly produced it have ceased to do so. Several causes 

 have been assigned for this lessened appreciation. Manufactur- 

 ers say that the cost has been so far reduced that the rich will 

 not buy it, and, in consequence, the middle classes no longer care 

 for it. But such is not the general course of events in industrial 

 matters, and the statement is to be taken with a grain of salt. 

 The probable trouble is, that some of the cameo-ware has been 



