Page:Popular Science Monthly Volume 37.djvu/178

166. Frequently the engraver originates his pattern as he goes along—a species of improvising which is quite full of interest to an on-looker. In time the men become very skillful in this sort of work, and are quite ready in thinking out new designs. It is entirely a matter of experience, the work depending largely on a nice sense of touch, since the glass is for the most part obscured by the spattered emery and oil. In this way geometric designs of considerable complication, wreaths and flowers, birds, fishes, and dragons, are traced on goblets and other table-ware, as well as on globes and similar articles. It is also the process by which initials and monograms are cut on glass, and its frequent application for this purpose is familiar to every one who is not nearsighted.

The tracery is accomplished sooner than one would fancy. As a rule, it is used in connection with some other form of ornamentation. Frequently in the case of globes there is a light tracery around the central portion, and plain bands at the top and bottom. These are put on very expeditiously, and, consequently, at little cost. The process is known technically as "obscuring." The globes are mounted on a lathe over a sand-box, being fastened between plates of cork in order that they shall not be fractured by the jar. The workman presses a bundle of soft, annealed iron wire against the surface of the quickly rotating globe, and, almost in less time than it takes one to tell about it, the band is completed. The band at the other end of the globe is put on in the same way. If two parallel bands are to be put on near together, the bundle of wire is in two parts, and both bands are made at the same time. The wires simply determine where the obscuring shall be. The real grinding is done by the sand and water with which the surface of the globe is kept constantly supplied. By using a larger bundle of wire, and passing it over the entire surface of the globe, the obscuring is made complete, and we have the so-called ground-glass globe.

The obscuring process is used in connection with both cutting and engraving, a design frequently being brought out much more beautifully by reason of the obscured or translucent background. In this case, however, the cut pattern must not be subjected to the final brushing process, for the glass brush would smooth the obscured surface and give it the almost transparent character displayed by ground glass when moistened with oil or water. The effect would be to make the portion of the glass around the cutting look constantly wet—an undesirable form of decoration. Some of the most pleasing designs are thus produced by a combination of two or more processes. However fully and artistically a plain glass globe may be decorated, there is apt to be an unpleasant effect of thinness of design from the unrestricted