Venice.— Glass-making has been a Vene tian industry since the end of the llth century. In mid-12th century Venice employed mosaic craftsmen. Half a century later other pro cesses, those practised by Greek and Byzan tine glass workers had been adopted there. Up to the last decade of the 13th century the art was practised within the city itself, but in 1291 it was decreed that the larger furnaces be de molished and the seat of the industry removed to nearby Murano. This law remained in force for nearly five centuries. About the beginning of the 14th century glass "lanterns° for galleys and lighthouses were made at Murano, also optical glass, in mass, for use by the makers of spectacles. Mosaic glass, beads, glass for windows and mirrors, vessels for ornament and domestic uses, were all separate branches, each conducted under its own code of laws, binding upon master and workman.
Manufacturing secrets were closely guarded, and the export of raw materials absolutely pro hibited. "Crackled" glass, variegated or "marbled° glass, imitations of tortoiseshell and various chalcedonic effects were among the varieties then made. The glass known as mille fiori came into use in the 15th century, and was long continued. The ancient Roman processes of manufacture had presumably been followed as there was a noticeable similarity in effect and appearance. The famous vitro di trims — also called glass of Venice also cor responded in some of its features with the more ancient products known as "lace,° "filigree° and "reticulated°; but the Venetian workman car ried this class of glass-making to its highest point of perfection. This-was undoubtedly the finest development of the art of manipulating threads of glass. Up to the middle of the 15th century the forms adopted by Venetian glass workers were of the massive order and bore a resemblance to the silver work of western Europe. Colored glass — largely blues and greens — with decorations in enamel colors and gold tracery, with occasionally figure subjects, was produced at this time. Decorations in gold leaf, both worked into the substance and spread over the surface, were also well-prac tised forms of ornamentation. Later more classical outlines in form were adopted, and by the middle of the 16th century had reached a very high standard of elegance and beauty.
At this time special privileges were granted by the Venetian Republic • to those who prac tised the art of glass-making and preserved it as a Venetian industry; but punishment, even to the death penalty, awaited those who carried its secrets to other countries.
The glass known as "avanturine° was a Venetian invention of the early part of the 17th century, and its manufacture remained a secret for at least two centuries. It has the appear ance of myriads of atoms of burnished copper diffused through a mass of transparent amber. It was largely used by the Venetians in con junction with other means of decorating glass. It has still many uses of an ornamental nature.
The full period of fame for Venetian glass can be reckoned in centuries, and with the possible exception of cameo glass, every variety of manufacture known to the industry seems to have been produced in some form, from beads and "burning glasses° to table wares and chandeliers. In the 17th century it reached its zenith, Venice supplied the world with its finest glass. The task, however, was a heavy one, and extensive distribution of the product, combined with other circumstances, forced western Europe — hitherto its best market into the competition, which by the middle of the 18th century had wrested from Venice much of its best trade. It is to this period we may assign the foundation of what is now, and has been for at least a century and a half, the principal factor in the flint glass industry, viz., cut glass. As Venice declined, the new aspi rants to precedence in glass manufacturing be gan their effort to advance "wheel-cutting° upon glass, as a substitute for the more fanciful materials which had served Venice so well in the centuries just passed. With atablewares° as its staple, cut glass then began its revolu tionizing influence. In the thirties of the 18th century one of the Murano manufacturers ob tained permission to re-establish the glass making industry in Venice itself, and with the additional protection of certain patent rights he succeeded in introducing a variety of produc tion somewhat different to that hitherto prac tised. Among his successes were mirrors, with frames of glass ornamented by methods which have been practised in several glass-making countries since that time, and are even now quite familiar in some. Chandeliers orna mented with flowers and foliage — all made in glass—and a continuation of earlier Venetian motives all contributed to the success of his endeavor.