Page:Popular Science Monthly Volume 29.djvu/364

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THE POPULAR SCIENCE MONTHLY.

previously covered with etcher's varnish, which is removed from the lines of the engraving, where the bare glass is afterward exposed to hydrofluoric acid. In this way are produced the wave designs resembling those which are seen on the more finely engraved banknotes.

In another very recent style of ornamentation, fine Venetian glasspearls of various colors are glued by a very fusible enamel upon the surface of the finished vessel. As the arrangement is made in the cold, the work admits of a complete artistic freedom. The enamel is then dried and the setting is fixed by heating.

Another important function of the melting-furnaces is to furnish raw material for the now considerable small-glass industries in the shape of sticks and fragments of colored glass. The favorite color for these is a dark violet or black; but colorless glass is used for the pendants of chandeliers, and they are sometimes given a reddish tint by overlaying them thinly with gold-ruby. Sticks partly overlaid with opaque glass are used in a similar manner. There are always accumulating, in the glass-houses and other shops, piles of droppings, overflows, and pieces of many colors, which can be sold for very cheap prices. All this stuff is pounded up and mixed together with the addition of manganese or other coloring oxides, and is remelted in a special furnace. The workmen take out suitable quantities of this mass, and, by a series of deft manipulations, form it into sticks about as thick as one's thumb.

Very thin globes of about the size and shape of a vitriol-flask are made from the same dark glass, to be again broken up into sherds, which can be packed away in boxes. The manufacturer cuts from these sherds slightly curved plates, such as are used, for example, as foundations for brocades.

The shops of the small-workers are of the simplest character. Wherever one of the numerous little streams makes it possible to get water-power enough to drive a grinding and polishing wheel, and in the modest houses scattered along the mountain-slopes, may be found the establishments of these industrials, in which the working force of the whole family finds active employment. The artisan buys his sticks and sherds from the glass-house. A little wood-furnace, somewhat like a tinker's furnace, gives facilities for heating four or five of the glass sticks at once, which are taken out and used alternately as the ends are softened in the fire. The softened end is fastened upon by a pair of pincers, drawn out a little, and introduced into a mold in which is carved the figure of the object into which it is designed to be formed, and which is firmly stamped upon it by closing the mold and the application of pressure. If the mold is too cold, the form will be imperfectly made and the glass will be brittle; if it is too hot, the glass is liable to stick in it. Fortunately, it can be easily worked to a suitable temperature. The molded pieces are thrown into an earthen