Glass Furnaces

Glass Furnaces were becoming so numerous in Venice that the Great Council decreed, in 1291, they should be demolished, but permitted them to be set up outside the city, in the suburban districts. In the following year, however, the decrees were altered to the effect that the small glass workers might remain in the Rialto (the city proper), provided fifteen paces were left between each atelier. These decrees were made to guard against a possible spread of fire.

It is supposed that this had the effect of moving many of the principal glass works to Murano, a district of Venice which had become renowned for the production of Venetian glass, and where to-day the eminent firm of Salviati & Co. have their extensive works.

The Glass House At Murano

The Glass House At Murano, which was known as the "Sign of the Angel" in the early half of the fifteenth century, was the most renowned of the ateliers of that century. Angelo Beroviero was one of its earliest directors, who was succeeded by his son Marino in that position. The latter was a head or master of the Company of "Phioleri" (Glass Makers' Corporation) in 1468, which was a very strong society at that time and enjoyed exceptional privileges from the city council.

The intercourse of Venice with the East furnished the Venetian glass makers with patterns of Damascus and Egyptian glass, and the enamelled and gilded Oriental varieties were imitated and improved on by the Murano artists. Some of the products of this period are preserved in the museums. The illustration (Fig. 300) is from a Venetian enamelled cup of green glass in the Kensington Museum.

In the sixteenth century the glass-making furnaces of Murano had increased to a great extent, and were placed under the special protection of the Council of Ten. Owing to the jealousy at this time of other European States, Venetian glass-blowers were bribed by offers of money and large salaries to set up furnaces abroad, and laws were then made forbidding workmen to leave the country to carry on glass making in other places under the penalty of death. This, however, did not prevent Venetian glass-blowers from taking service under the protection of foreign rulers in such countries as Flanders, Spain, and England.

The natural consequences followed, that the exports in glass from Venice to foreign countries became lessened, so much so that the workmen of Murano complained of being thrown idle for several months in the year.

Venetian Glass

Venetian Glass has been made in many colours, such as blue, green, purple, amber, and ruby, and in variegated mixtures of clear or transparent and opaque glass. The clear variety is remarkable for elegance of shape and fantastic designs of handles or wings, consisting of twisted and knotted interlacings, which were generally executed in blue or red colours and attached to the sides of wineglasses and other vessels (Fig. 301). One beautiful variety of glass is clouded with a milky-like opalescent tint, which is supposed to be produced from arsenic. The opaque white glass is made by the addition of oxide of tin to the usual ingredients.

Glass was made by the Venetians to imitate precious stones, were streaked, splashed, or spotted with various colours, gold, and copper; the aventurine spotted glass was obtained from a silicate of copper.

Fig. 299. Enamelled Oriental Glass Bottle and Mosque Lamp.

Fig. 300. Venetian Enamelled Glass; Fifteenth Century. (S. K. M).

Fig, 301. Venetian Glass of the Sixteenth Century. (J).

The Latticinio Variety

The Latticinio Variety was formed of rods of transparent glass enclosing lines of opaque white glass forming patterns. The vitro di trina is the so-called lace-glass (Fig. 302); the latter and the mosaic - like or mille -fiori glass were made by the Venetians in imitation of the Roman varieties. Another variety was that known as a reticellty in which ornament of opaque network sometimes enclosed air bubbles. That known under the German name of Schmelz is the variegated or marble opaque glass made in the Murano furnaces, which imitated chalcedony, lapis lazuli, tortoiseshell, and jasper. Crackled glass was made by the sudden cooling of the half-blown material; this was again heated and drawn out in order to increase the spaces between the crackled lines.

In the sixteenth century the forms of the Venetian glass vessels were of the Renaissance type; the long shanks and the wide bowls gave them an appearance of elegance and grace. The light and thin character of the material had also a great deal to do with the fragile look of elegance in Venetian glass of this period; the glass of the former (fifteenth) century was of a much thicker kind.

The lightness and superior strength of Venetian glass was due to the absence of lead in its composition, which i$ so much used in the modern flint glass.

The materials of the composition of the clear Murano glass are supposed to be - one part of alkali, obtained from ferns, moss, lichen, or seaweed, and two parts of pebbles of white quartz or fine clean white sand, and a small quantity of manganese, all well mixed together and melted in the furnace.

The colouring matter is produced from the oxides of various metals, as in the vitreous coloured glazes used in the enamels for glazed pottery.

Vessels and objects in endless variety have been made by the Venetians, such as ewers, basins, drinking-glasses, bottles, standing cups, bowls, goblets, large and small candlesticks, beads, and mirrors, and were exported in great quantities to all parts by the Venetian galleys.

Bead Making At Venice

Bead Making At Venice was a separate trade, and was one of great importance in the sixteenth and two following centuries. The makers of the small beads were called the "Margariteri," and those who made the large beads were known as the "Perlai." The beads were made from small sections broken or cut off from rods or tubes of glass and placed in an iron pot that was made to rotate, so that the motion prevented the beads from adhering to each other, and at the same time formulated their spherical shape.