Who was the first to start glass smelting? When did the first glass appear? Industrial glass production
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35This article describes the history of the emergence of glass and the development of glass making in the world from the times of Ancient Egypt to the present day. Particular attention is paid to window glass production methods used at different times.
Origin of glass
The production of sheet glass began about 2000 years ago. But before its appearance, there already existed basic techniques for working with molten glass and a variety of techniques for making simple glass products in the form of beads, vessels and bracelets.
The emergence of ancient glassmaking dates back to approximately the 3rd millennium BC. e. By this period, ancient masters created a new material - glass. The creation of glass is a colossal scientific and technological achievement in terms of the scale of its discovery; its appearance in the history of technology and culture can be compared with the discovery of metals, ceramics and metal alloys.
How, where, when and who started making artificial glass? There are different versions of this question. Glass is an artificial material created by man, but natural glasses are also known - obsidians, which are formed in magmatic melts at high temperatures during volcanic eruptions and meteorite falls. Obsidians are translucent black glasses that are highly hard and resistant to corrosion and were used in ancient times as a cutting tool. Some believe that it was obsidians that prompted man to create their artificial analogues, but the areas of distribution of natural and artificial glasses do not coincide. It is most likely that ideas about glass developed in close connection with the production of pottery and metalworking. Perhaps, in the early stages of glassmaking, ancient craftsmen saw analogies in the properties of glass and metals, which were determined by the technological methods of glass processing. Having recognized glass as similar to metal (ductility when hot, hardness when cold), the ancients created the opportunity to transfer metal processing techniques to glassmaking. In this way, crucibles for melting glass mass, molds for casting products, and technological methods of hot processing (casting, welding) were borrowed. This process occurred gradually, especially in the first stages, glass and metal are so different in nature.
The earliest “theory” of the origin of glass was proposed by the Roman scientist Pliny the Elder in Natural History:
“Once upon a time, in very distant times, Phoenician merchants transported a cargo of natural soda mined in Africa across the Mediterranean Sea. For the night they landed on a sandy beach and began to prepare food for themselves. Due to the lack of stones at hand, they surrounded the fire with large pieces of soda. In the morning, while raking out the ashes, the merchants discovered a wonderful ingot that was hard as stone, burned with fire in the sun and was clean and transparent like water. It was glass."
This story is not very reliable, even Pliny himself begins it with the words “fama est.....” or “according to rumors...”, because the formation of glass at the temperature of a fire flame in an open space cannot occur. The most likely assumption is that of the German scientist Wagner, who connects the appearance of glass with the production of metals. In the process of melting copper and iron, slags were formed, which could turn into glass under the influence of heat. It is now difficult to establish exactly how glass was invented, but without a doubt this discovery was accidental.
The most ancient products had only a glassy layer on the surface of the faience, and were found in the tomb of Pharaoh Djoser (III dynasty of the Old Kingdom in Egypt, 2980-2900 BC). Glass samples in the form of ingots dating from the 22nd-21st centuries. BC e., discovered during excavations in the region of Ancient Mesopotamia.
Glassmaking in Ancient Egypt and Mesopotamia
The earliest archaeologically known glass workshops date back to the mid-2nd millennium BC. e. It should be noted that first the material itself (glass) was obtained, and then its novelty was realized and its properties were revealed. Processing techniques for a new material are selected in relation to its properties: stretching, bending, twisting. Only over time were other techniques selected and adapted: casting, pressing, rolling.
The history of glassmaking begins with the making of beads. The new material found its application in the non-industrial sphere, and products made from it were equated with the values of noble stones and gems. The glass beads of Queen Hatshepsut, who ruled Egypt in 1525-1503, are considered to be the oldest glass items. BC e. and a glass goblet bearing a hieroglyphic inscription with the name of Pharaoh Thutmose III, dating back to the New Kingdom.
By the middle of the 2nd millennium BC. e. glassmaking developed in its main features almost simultaneously in different centers of the ancient civilizations of Egypt and Mesopotamia. The only source on the basis of which one can judge the formation and initial stages of the history of glass and its origin are finished products: beads, inserts, vessels. According to scientists, beads served as amulets for the Egyptians.
Since the middle of the 8th century. BC e. The set of finds is expanding and rings, bracelets, ritual and toilet utensils are being added to the beads and vessels, which began to be found not only in the Mediterranean region, but also in the Caucasus and Western Europe. The decorativeness and complexity of the found products increase significantly. The technique of making products is becoming more complicated; craftsmen, along with molding, winding and casting, have mastered other techniques for working with molten glass: cutting, engraving, grinding, polishing and pressing in forms of different designs and materials. Techniques for processing glass mass were accompanied by an increase in the complexity of tools and workshop equipment.
Invention of the glass blowing process
By the beginning of the Roman period, glassmaking had accumulated a very large production experience and knowledge in order to make a genuine revolution in the field of technology for manufacturing glass products.
The first “revolution” in glassmaking is considered to be the invention of glass blowing. The process of blowing products from molten glass began with the most important invention - the glass blowing tube by Syrian craftsmen between 27 BC. e and 14 AD e. With the discovery of the glass blowing process, Syria became the largest glass-making center for hundreds of years. The invention of blowing led to the birth of a new quality and formed the basis of not only ancient, but also modern methods of making glassware, and subsequently window glass
Blowing, previously an auxiliary operation, began to be used as an independent technique in Roman times. After collecting glass melt onto a glass blowing tube, the master blew the initial blank into a wooden mold and received various hollow glass products in the form of jugs, jars, and bottle cups. Along with simple tableware, craftsmen also made decorative unique objects decorated with threads and colored glass overlays.
First window glass
The first window glass, truly flat glass, first appeared much later, in Ancient Rome. It was discovered during excavations at Pompeii and dates from the year of the eruption of Mount Vesuvius, 79 AD. e. Window glass was produced by casting onto a flat stone surface. Of course, the quality of the glass was very different from modern glass. This glass was colored in greenish tones and matte (at that time they did not yet know how to make colorless glass), contained a large number of bubbles, which indicated a low cooking temperature, and was quite thick (about 8-10 mm). But, nevertheless, this was the first case of glass being used in architecture, which gave a significant impetus to the further development of glass making and the spread of glass throughout Europe.
Crown process
The 2nd revolution in glassmaking occurred around the beginning of the 2nd century, when Syrian craftsmen invented a technology for producing flat glass that was completely new for those times - crown, or as it was called in Russia, the lunar method. This idea may have originated from the blowing of large flat plates. Glass was made by blowing large bubbles, which in the next stage were separated from the glass blowing tube and attached to another tube - a pontium. After intense rotation on the pontoon, the original workpiece became thinner under the influence of centrifugal forces and turned into a flat round disk (see figure). The diameter of this disk could reach 1.5 m. After cooling, square and rectangular pieces of glass were cut out of it. The central part of the disk had a thickening - a mark from the pontic, which was called the “bull's eye”. As a rule, this part of the disk was not used and was melted down, however, in some medieval buildings these round pieces are still preserved (see figure).
This technology made it possible to obtain glass of fairly good quality for those times, with virtually no distortion. It is not surprising that this technology lasted until the mid-19th century. Thus, the well-known and one of the oldest glass manufacturers in the world, the English company Pilkington, completely stopped using the crown process only in 1872.
However, there was also a problem - size limitations. Using the crown process it was impossible to produce glass of large size. Therefore, over the years, attempts have been made in various European countries to improve this technology, which led to the creation of a new method of glass production - the cylinder blowing method.
Production of window glass using the cylindrical method
In general, this method was very similar to the crown process, but in this case, the glass blower collected glass from a pot in several stages and inflated the workpiece (pellet) into the shape of a cylinder while constantly rotating. To form a cylindrical shape, the master rocked the workpiece in a special rectangular pit. After the workpiece hardens, the tapered ends are separated with a special heated hook. Then a longitudinal cut is made inside the cooled cylinder and straightened into flat sheets in special “straightening ovens”, where the cylinders are gradually heated until their clay softens on the flat bases and smoothed into a sheet with a wooden block attached to an iron rod. By the end of the 19th century, air pumps began to be used to blow out cylinders, and soon a method of mechanically drawing out cylinders appeared (see figure).
The use of a more efficient method of producing window glass has increased the size of sheet glass and reduced the amount of scrap glass waste. Thus, installed in 1910 at one of the English Pilkington factories, the air machines of the American engineer John H. Lubbers made it possible to produce glass cylinders up to 13 m long and up to 1 m in diameter.
Production of window glass by melt drawing method
William Clark from Pittsburgh was the first to propose a method for producing sheet glass by drawing a melt from a free surface. In 1857, he presented an English patent, according to which the formation of a flat sheet is carried out by slow vertical pulling of a seed from the surface of the melt. Over the next 50 years, they tried to solve the main problem - the narrowing of the glass strip when stretched, but all attempts were unsuccessful.
In 1871, the Belgian inventor F. Vallin received a French patent (No. 91787) for the production of window glass by mechanically drawing glass. For a continuous supply of melt, he proposed a system of pots that were connected to each other by a tube, so that the glass melt from one pot flowed into another. A metal plate (seed) was lowered into the last large oval pot, which was enclosed in a pipe. The formation of a flat sheet occurred when this plate moved upward. The pipe also contained air tubes on the sides of the glass with holes for cooling the glass. The glass sheet was supported by rollers covered with asbestos fabric. Glass stretching can occur in two directions: vertical and horizontal. In the latter case, a special metal roller was provided. Wallin was a brilliant inventor and proposed almost all the basic elements of mechanical drawing, which in the 20th century would be used in all methods of glass drawing. At a time when bath furnaces were unknown, he introduced a system of glass melting pots, in which the clarified glass melt was fed from below through tubes from one pot to another, to the main one, from which the glass was drawn. This system of continuous supply of melt became the basis for the emergence of bathtub glass melting furnaces. In 1890, Wallin founded a company in Gifors to produce window glass by mechanical drawing.
In 1905, the Belgian engineer Emile Fourcault proposed his own method of vertically stretching glass. This oldest method (VVS) uses a fireclay boat, from the crack of which a constant stream of glass flows out under the influence of hydrostatic pressure. The pulling speed can be adjusted by the depth of the boat's immersion. The glass ribbon from the boat entered the shaft chamber, where there were water-cooled tubes on both sides, and then passed along rollers into the annealing furnace. To prevent the tape from narrowing, bead-forming rollers and cooling tubes were installed at the edges of the belt. The thickness of the glass strip was determined by the drawing speed and the temperature in the drawing zone (“bulb”). The first Fourcauld machines for drawing sheet glass were installed in Belgium and the Czech Republic in 1913. The productivity of 11 machines installed on one bath furnace was 250 tons of glass per day.
The glass drawing process made it possible to produce cheap window glass with fire-polished surfaces. The main defect of drawn glass appears during molding (drawing) and is associated with a violation of the flatness of the glass. Such disturbances lead to optical lens effects and image distortion. Drawn (machine-made) window glass was widely used in construction for glazing windows and greenhouses.
Production of window glass by casting and grinding
As mentioned above, both the crown process and the cylinder blowing method, and the Air Force method, had a number of disadvantages associated either with the presence of optical defects and distortions, or with the inability to obtain large sheets of glass. Therefore, as an alternative, from the beginning of the 19th century in Europe, another method of production was also used by casting and subsequent annealing of cast rolled glass. In it, a pot of molten glass was poured directly onto a pouring table and rolled by rollers. For annealing, a special furnace with several rows of shelves was used, which made it possible to increase the loading capacity. Rolled glass could be made of any required size and thickness of 3-6.5 mm. This method was used to make colored and clear patterned glass, as well as large sheets of unpolished window glass. Patterned colored glass was especially popular for glazing windows in churches and cathedrals.
Subsequently, with the emergence of the need for higher quality glass, abrasive processing of glass surfaces began to be used at the final stage. At the time, it was a labor-intensive, time-consuming and multi-step process that involved moving a pot of molten glass, casting and rolling into sheets, annealing, grinding and polishing. Glass processing time was about 17 hours.
In the early 20th century, the growth of the automobile industry stimulated the development of more efficient, high-throughput methods for producing polished glass. One of the pioneers of this method was also the Pilkington company, which in 1923, together with Ford Motors, developed and launched a continuous process for the production of rolled glass. The glass melt was melted in a furnace bath and passed through a drain device in a continuous flow through water-cooled shafts and pressed to a given thickness. The main problem was obtaining a high-quality melt in a bath furnace. In 1925, this method was supplemented with a single-sided grinding and polishing machine. The next step towards automation of production was the development of machines for double-sided grinding and polishing of glass. After much experimentation and difficult assembly work, the first polished glass production line was launched at the Pilkington factory in Doncaster (UK) in 1935. A continuous ribbon of glass, 300 m long, moved at a speed of 66 m/hour and was processed simultaneously on both sides by huge flat grinding discs. The introduction of this technology was the most significant development in the long history of polished glass production.
More expensive polished glass had good optical quality and was successfully used for glazing buildings, shop windows, transport, and making mirrors. But the process of producing polished glass has always been characterized by high energy intensity, high operating and capital costs. Glass waste during grinding and polishing reached 20%. For example, the production line of double-sided continuous grinding and polishing of the Pilkington company in Cowley Hill (UK) in 1944, including a glass furnace, lehr, grinding and polishing machines, stretched for more than 430 m. Contemporaries noticed with pride or regret that the production line was 21 m longer than the largest ocean liner at the time, Queen Mary.
By the middle of the 20th century, there was a need to use new, simpler and cheaper methods for producing high-quality glass.
Transition to new methods of window glass production - float process
The credit for creating a revolutionary method of producing polished glass (the float process) belongs to Sir Alastair Pilkington.
Lionel Alexander Bethin (Alastair) Pilkington was born in 1920, and after leaving school in Sherborne he entered Trinity College, Cambridge, where he received his first degree in mechanical engineering. During the war he left university and joined the Royal Artillery. Participated in hostilities in Greece and Crete. After being released from captivity at the end of the war, he returned to Cambridge to continue his studies and decided to pursue a career as a civil engineer. In March 1947 he was appointed technical assistant at the Pilkington plate glass factory, and two years later he became production manager at the Doncaster factory. In 1952, Alastair returned to St. Helens, and under his leadership, experimental work began on the development of the float process. As a result of his first experiments, he proposed using a melt of metal to form and transport glass strips. In 1953, a sample of float glass 300 mm wide was produced at the first pilot plant. In 1955, a new pilot plant produced 760mm wide float glass, and the Pilkington board made the bold and risky decision to build a 2540mm wide float-line. The company hoped for success, but at the same time understood that if it failed, financial losses would amount to millions of pounds. On the other hand, the successful launch of the line guaranteed a significant and revolutionary leap in flat glass technology throughout the long history of glass production.
The float production line was introduced at Cowley Hill (UK) on May 6, 1957. Many at that time did not believe in the new process, and said that this line would not produce even 1 m² of glass. Only 14 months later, the first high-quality float glass (float-glass) with a thickness of 6.5 mm was obtained, and on January 20, 1959, the Pilkington company officially published a press release in which it introduced the float process in the following words:
"The float process is the most fundamental, revolutionary and important advance in glass production in the 20th century"
In accordance with the float method developed by the Pilkington company, glass melt from the glass pool at a temperature of 1100 ° C is conveyed in a continuous ribbon from the glass furnace to the surface of the molten tin. The tape is kept at a high enough temperature to remove all defects and irregularities on the glass surface. Since the surface of the molten metal is a perfectly smooth surface, the glass acquires a “fire-polished” shiny surface that does not require further grinding and polishing. During experiments, it was established that the molten glass mass does not spread indefinitely on the surface of molten tin. When the forces of gravity and surface tension are balanced, the tape reaches an equilibrium thickness of about just under 7 mm. To obtain glass strips of various thicknesses, methods were created based on regulating the viscosity of glass in the forming zone and the magnitude of the tensile force. If it is necessary to obtain a glass strip thickness greater than 7 mm, then it is compressed by non-wetting side limiters.
At the beginning of the work, the problem arose of choosing a molten metal, which should be in a liquid state within the temperature range from 600 to 1050 ° C, have low vapor pressure values, and the density value should be higher than glass. Research has shown that tin, which almost does not interact with glass, meets all these requirements and is a completely accessible and cheap product. But tin at high temperatures is oxidized by oxygen to form oxide compounds. Therefore, in order to prevent oxidation of the surface of the tin melt, it is necessary to create an inert atmosphere of nitrogen with a small addition of hydrogen in the float bath. After molding, the glass strip is cooled to 620°C and transported to an annealing furnace.
They think wrongly about things, Shuvalov,
Who honor Glass below Minerals,
An alluring ray shining into the eyes:
No less useful in it, no less beauty in it.
It’s not uncommon for me to go down from the Parnassus Mountains for that one.
And now I return from her to the top of them,
I sing praises before You in delight
Not expensive stones, nor gold, but Glass.
M. Lomonosov.
Ancient glass
Glass accompanies man at all stages of the history of his development. The beginning of glassmaking is lost in the mists of time and, constantly evolving, continues to this day. However, oddly enough, in modern science there is neither a single theory of the structure of glass nor a single theory of its origin. Only the most common assumptions are presented.
The earliest theory of the origin of glass was proposed by Pliny the Elder (79 AD). “There is a legend,” writes Pliny, “as if a ship of soda traders landed at the mouth of the river. Scattered along the shore, they prepared dinner, and since there were no stones to put under the pots, they put in pieces of soda; when these latter warmed up and mixed with the coastal sand, then streams of new liquid flowed, which was the beginning of glass.”
In later times, attempts were made more than once to reproduce this experience, but they were unsuccessful. Thus, Pliny’s “theory” turned out to be just a legend.
There is a theory that man-made glass was invented by accident, as a by-product of other crafts. In those days, clay products were fired in ordinary pits dug in the sand, and straw or reed served as fuel. The ash formed during combustion, that is, alkali, at high temperatures in contact with sand gave a glassy mass. Some consider glass to be a by-product of copper smelting.
The oldest man-made glass item found to date is considered to be a light green bead measuring 9x5.5 mm, discovered in the vicinity of the city of Thebes - dating back to the 35th century. BC.
But long before this, people knew the so-called natural glass - a material resulting from the melting of rock during a volcanic eruption (obsidian), lightning strike or meteorite (tektite). Its most common variety is obsidian, a natural volcanic glass from which ancient man made a variety of tools. But even in the later period of human development, obsidian was not forgotten, as evidenced by the fact that numerous obsidian products were found on the territory of Egypt.
It is sometimes believed that natural glasses - obsidians and tektites - prompted man to create their artificial analogues.
One way or another, the beginning of ancient glassmaking dates back to the middle of the 3rd millennium BC. and is associated with civilizations in the Nile, Tigris and Ephrata valleys, the island of Crete and individual peoples, for example, the Phoenicians. In Egypt, glass production reached its peak during the 18th Dynasty (1560-1350 BC), when the capital, Thebes, became the center of glassmaking. A glass jug and a bead with the name of Pharaoh Thutmose III have come down to us from this era. Beads are the oldest objects made entirely of glass. Such beads were worn by representatives of the royal house, and they were not so much jewelry as amulets. These were luxury items available only to very influential and wealthy people.
The Egyptians produced colored glass, while Mesopotamians preferred clear glass. The first glass products were decorations - beads, sticks, strips. However, already in the 16th century. BC. In Mesopotamia, they learned to make glass vases; their fragments have been found by modern archaeologists.
Around the same time, the secret of producing hollow glass was mastered in Egypt. Egyptian craftsmen placed a mold made of compressed sand into molten glass and rotated the mold so that the glass settled on the sides of the mold. Then the mold with glass was taken out, the sand was removed, the workpiece was cooled and final processing was carried out. Three vases from those times have reached us, bearing the name of Pharaoh Thutmosis (Thutmose) III (1594 - 1450 BC), who brought glassmakers to Egypt as prisoners of war after a successful campaign in Asia.
Archaeologists were also able to discover the remains of ancient glass workshops on the eastern bank of the Nile, which worked approximately 3,400 years ago. Crucibles for melting glass have been preserved there, shaped like small barrels with a height of 40 cm and a diameter of 27 cm in wide places and 23 cm in narrow ones.
Later, glass began to be produced in Mycenae (Greece), China and India. From the 10th century BC. we can talk about glass production in the Far East. And from the 9th century BC. Alexandria became the center of glassmaking, from where it spread to Rome.
Ancient glassware was usually colored greenish or brownish due to impurities in the glass. Products made of colorless glass were especially prized. It is known that the Roman Emperor Nero (37-68 AD) paid for two flint glass bowls in gold exceeding their weight.
They learned how to make counterfeits of precious stones from colored glass. These fakes were valued on par with jewelry made from natural stones. It is known that since ancient times, gemstones have been credited with miraculous properties that help their owners. Thus, it was believed that sapphire gives clarity to thoughts and cures leprosy; emerald (emerald) drives away bad dreams, removes black thoughts and calms the heart; turquoise brings happiness in love; amethyst softens anger, curbs the wind and protects against intoxication; beryllium is a good companion of wanderers and heals thorns; garnet or anthrax gives the wearer power over people and awakens love passions: jasper heals all diseases, and so on. The same properties were attributed to colored glass. Already in ancient Egypt they knew how to make colored beads in imitation of many precious stones.
Fine examples of glass scarabs (Egyptian sacred beetles) are kept in the Pushkin Museum of Fine Arts in Moscow.
The first "instructions" for making glass date back to around 650 BC. These are tablets with instructions on how to make glass, which were in the library of the Assyrian king Ashurbanipal (669 - 626 BC).
A great revolution in glassmaking was made by the discovery of glass blowing. This happened between 27 BC. and 14 AD The innovation is attributed to Syrian craftsmen who lived in the Babylon region. Glass was blown using a thin metal tube, which has changed little since then. This method made it possible to significantly diversify the shapes of glass vessels.
In the 1st century AD glassmaking penetrated from Egypt to Italy and then spread throughout the Roman Empire. Rome became the largest center of glassmaking, numerous workshops appeared in Spain, Gaul (modern France), Southern Britain, Germany and along the northern coast of the Black Sea in the territory of modern Ukraine.
In the last century BC. Glassmaking developed intensively in the Roman Empire. It was the Romans who began to use glass for architectural purposes, especially after the discovery of transparent glass by introducing manganese oxide into the glass mass (around the 1st century BC in Alexandria).
At the turn of the old and new eras, the first glass windows appeared in Rome. And although at that time they had poor optical properties, they were considered a sign of luxury. Cicero said: “Poor is he whose home is not decorated with glass.”
With the fall of the Western Roman Empire (476) and the emergence of the barbarian Germanic states on its ruins, glassmaking in Western Europe fell into decline, and its center moved to the new capital of the world, Constantinople.
Having founded a new capital in Byzantium, the Roman Emperor Constantine took great care of its decoration and resettled artisans and artists from Rome there, attracting them with various benefits. Many categories of artisans, including glassmakers (mirror makers, mosaic makers), were exempt from taxes. Constantinople maintained its leading position in glassmaking for many centuries. Particularly well known is the Byzantine colored mosaic, which decorates numerous churches in Italy and Greece. This mosaic was simply called "Greek glass".
Venetian glass.
Venice arose in 607, and glass workshops immediately appeared there. From the 1st century, Venice began to compete with Constantinople. Venetian craftsmen developed their own secrets of glass compositions and methods. Venetian mosaics and stained glass windows decorating churches in Venice itself and Northern Italy are well known. After the capture of Constantinople by the Crusaders (1204), Venice remained the only world center of glassmaking.
Venetian merchants, sailing throughout the Mediterranean, provided Italian craftsmen with the secrets of Syrian glass production and introduced the Italians to the traditions of Islamic art. Venetian glassmakers had no equal in Europe. At this time, the Venetians brought priceless samples of Oriental glass from Constantinople, taking possession of some important secrets of the craft. The authorities were well aware of the importance of glass production for the city and established protectionist conditions for local glass and at the same time protected the secrets of its production (the import of glass into Venice was prohibited, foreign glassmakers were not allowed to work in Venice, and the raw materials for glass production were forbidden to be exported abroad).
Venetian craftsmen achieved high perfection in the manufacture of various jewelry and vessels. Venetian inventions include “vessels in a net”, diatret vases, “Venetian glass” is usually decorated with gold, colored glass threads, and small bubbles (“midges”). The main specialty of glassmakers was the production of jewelry from colored glass - beads, seed beads, artificial pearls, fake jewelry and semi-precious stones. Counterfeits of copper aventurine, jasper and agate deserve special attention as they are the most difficult to make. Venetian mirrors were very famous. It is known that the Venetian envoy presented the mirror to Marie de Medici as a wedding gift (1600). It measured only 14 x 16 cm, but had no price.
In the 15th century, Murano glass was extremely highly valued throughout Europe. Venetian doges presented Murano products as precious gifts to important people visiting the city. Contemporaries were sincerely amazed that from glass - an essentially low-value material - Murano masters managed to create real works of art.
In the 16th century, the fame of Murano glass became truly global. It is purchased everywhere as a luxury item. The creations of Murano masters achieve incredible subtlety. Literally. The vessels confuse with their weightlessness, the glass mass amazes with its phenomenal purity and transparency. Images of traditional transparent Venetian tableware can be found in abundance on the canvases of Italian painters.
The unique skill and artistic ingenuity of Murano glassmakers was reflected in an exceptional variety of forms. Jugs, decanters, flasks, vases, salt shakers, bowls, glasses were made in Murano in huge quantities. Particularly popular were drinking vessels in the form of birds, whales, newts and lions, bell towers and barrels, and especially galleys and gondolas (these small glass ships, fortunately, have been preserved in museums in Western Europe). Objects made of transparent and tempered glass were usually decorated with welded-on colorless or painted parts: rosettes, masks, convexities in the form of drops and bubbles; the edges of the vessels were made wavy and curved. Bird and animal tails, paws, wings, combs often played the role of fancy and at the same time functional decorations...
The most popular goods at this time were chandeliers, richly decorated with clusters, flowers and leaves - an irreplaceable and necessary accessory for the decoration of the times of Louis XV.
Until the 18th century, the Senate fundamentally rebelled against any foreign innovations in the field of glassmaking, trying to preserve the purity of the national character of Venetian glass products.
Prices for Venetian products reached the equivalent of gold by weight. A master accepted into a glassmaking workshop received the title of nobility. A marriage between such a master and the daughter of a noble nobleman was not considered a misalliance. But glassmakers were forbidden to leave the Venetian Republic, and revealing professional secrets was punishable by death.
With the development of glassmaking, fires became more frequent in the city. Under this pretext, in the 13th century, all glass workshops were transferred to the island of Murano, two kilometers from the capital. (From that time on, Venetian glass became known as “Murano” glass, and this island remains a symbol of high-quality glass to this day.)
But there was another reason. According to Byzantine law, “barbarians” (foreigners) were forbidden to pay in gold for the goods they brought and sell them luxury goods, “so that those tempted by the taste of such would not decide to invade the state with great ease.” The embargo also extended to glass. There was a special police that monitored compliance not only with this law, but also with the strictest preservation of the secrets of craftsmanship. In fact, the glassmakers lived on their island as prisoners under house arrest. There were known cases when a master, having deceived the vigilance of the guards, moved to one of the European capitals to open a workshop there. The duty of the police was to follow the criminal, find him and kill him. Therefore, many of the secrets of the Venetian masters were lost forever.
The tragic page in the history of Murano is the occupation of the island in 1797 by French revolutionary troops and the destruction in 1806 of all workshops and corporations in the name of freedom, equality and fraternity.
The Venetian glass industry owes its revival in the mid-19th century to the lawyer from Vincenza, Antonio Salviati, an ardent patriot and a great businessman. With the financial support of two Englishmen, great admirers of Venetian antiquity, Salviati founded a factory in Murano and resumed the production of magnificent glass products that “imitated” the great examples of the past. It was a return to its former glory.
Since then, interest in Venetian glass has not waned. There are enough collectors in the world who regularly add to their collections, including at representative European auctions. Things with the Murano signature not only do not go out of fashion, but only increase in price over the years. A number of circumstances make them desirable for connoisseurs of fine art, because these objects are one of those that invariably create a festive atmosphere.
Today, like many years ago, new factories and workshops are opening on the island of Murano. And like many years ago, the production of glass objects - from dishes to mirrors - is carried out in only three ways: blowing, casting and pressing. It should be noted that the last two were invented only in the 19th century, so the old masters used the only technique - blowing. This technology is applicable only to glass. The master arms himself with an iron tube, one-third covered with wood (so as not to burn his hands) and equipped with a mouthpiece at one end and a pear-shaped thickening at the other for collecting glass. The end of the blowing tube, heated over a fire, is dipped into the molten glass mass, which easily adheres to the tube, forming a hot lump. Quickly removing the pipe from the oven, the master instantly begins to blow into it from the opposite end. A hollow space is formed in the glass coma, increasing as air is blown into it... For two thousand years, the iron tube of the master glassmaker has not undergone major changes.
European glass
During this era, in all countries of Western Europe, intensive development of glassmaking took place with the active participation of fugitive Venetian craftsmen, attracted by the prospect of huge earnings. Thus, in the 17th century, Colbez, attracting Venetian mirror makers to France, not only paid them huge salaries, but if he married a French woman, he gave them a dowry of 25,000 ecus. Therefore, despite the strictness of supervision and cases of murder of escaped glassmakers by agents of the Venetian government, it can be said without exaggeration that modern Europe went through the school of glassmaking under the leadership of the Venetians.
With the collapse of the Roman Empire, glassmaking in various regions began to acquire its own characteristics. Alexandria continued to be the center of glassmaking in the east, producing luxurious items for export. In the west, Cologne (Germany) became a major glass producer. German glass was less elegant and ornate than Alexandrian glass.
In the early Middle Ages in Europe, glassmaking underwent some changes. Due to difficulties in importing raw materials, glass made using soda gave way to glass made using potash, obtained by burning wood. In the wooded areas of France, Germany, and Bohemia, glass was prepared using wood ash and the ash of ferns, reeds, and other plants. Potash (potassium carbonate) predominated in this ash. The ash of different plants gave glass different properties: aspen, maple, ash - the best color, birch - greater refractoriness, etc.
It is interesting to note that French glass is XN!! Centuries (glasses, glasses) were called “fern glass” (“fougère” in French - “fern”).
The medieval glassmaking technique was reflected in a special treatise on artistic crafts, compiled by the learned monk-presbyter Theophilus from the Pantaleone monastery in Cologne (10th - 11th centuries). The author describes craft techniques based on his own observations. He names different countries that were famous for artistic production, among them Byzantium, Arabia, Rus', Italy, France, Germany. Unselfish in character and motives, Theophilus, without the secrecy usual in those days, shares the secrets of mastery that he had to obtain through dangerous travels and trials. He also writes about the ability to produce colored glass enamels in France, Germany and Rus'.
In medieval Western Europe of the Gothic era, the most important area of art that stimulated the development of taste for artistic glass was the production of stained glass. At that time, a red-hot iron rod was used to cut glass. Diamond for cutting glass began to be used only in the 16th century.
In the 11th century, German craftsmen, and in the 13th century, Venetian craftsmen, learned to produce flat window glass using the so-called “holy method”.
“Holyava” is a glass bubble that a master glassmaker blew using a glass blowing tube and swung it over a ditch, standing on a special platform. Under the influence of gravity, the bubble was pulled into a cylinder up to 3 meters long and up to 45 cm wide. Then the top and bottom of the cylinder were cut off while hot, the cylinder itself was cut to length and laid on a flat slab, which was placed in an oven and leveled there. The sheets thus obtained were fastened together with lead strips and installed in the window. Such windows were considered a luxury item; they were used mainly in royal palaces and churches.
Medieval alchemists made a significant contribution to the science of glass. In addition to being excellent glassblowers who made vessels of complex shapes for their experiments, they experimented with glass compositions. In the second half of the 17th century, the famous German alchemist Johann Kunkel, author of the work “Experimental Art of Glassmaking,” invented a method for producing red glass, the so-called “golden ruby” (the Kremlin stars were made from such glass). This method, kept by the author in the strictest confidence, was lost with his death, and was rediscovered only in the 19th century by M. Lomonosov.
The further development of glassmaking in Europe went in two directions - improving methods for making products and enriching glass compositions.
New types of products have appeared - optical, technical, building glasses.
A whole revolution in the glass industry of the 17th century was caused by the discovery of Mikhail Müller, who for the first time welded glass, which was distinguished by its extraordinary transparency in thick-walled products. This glass is known as “Bohemian crystal”, and the tradition of its production has survived to this day. Massive cut products made from Bohemian crystal displaced light, fragile and delicate products from the island of Murano from European markets.
In 1674, the Englishman George Ravencroft patented a new method of producing crystal, designed to replace Murano crystal. Ravencroft replaced potash with lead oxide in high proportions, which allowed him to obtain shiny glass with high refractive properties. This glass lends itself well to cutting and engraving. The main advantage of English lead crystal, which has earned it European fame, is the play and sparkle of polished edges, refracting rays of light, and the melodic ringing.
In 1688, a new method of making glass and mirrors was used in France. Molten glass was poured onto a special table and rolled out to a flat state. The workpiece was then cooled and polished using iron discs and very fine abrasive sand. Final polishing was done with felt discs. The result of this process was glass with unprecedented high optical properties. Coated on one side with a reflective layer of silver, the glass turned into a high-quality mirror.
Glassmaking in Russia
The development of glassmaking in Russia has passed through a thorny path.
Foreigners called ancient Rus' a country of cities, were amazed at the development of crafts and arts, and spoke of Kyiv as a rival to Constantinople.
Glassmaking in Russia developed in the 9th - 10th centuries, i.e. much earlier than in America (17th century) and earlier than in many other countries of Western Europe (England, Sweden, Venice, Bohemia, Lorraine, Normandy, etc. .).
In the 10th-11th centuries, workshops already existed in Kyiv for the production of glass bracelets, beads, rings and thin glasses.
They also made “window circles” - round glass for windows, made by casting molten glass onto a metal plate. In Rus' in the 11th-13th centuries, thick-walled window glass was used only in a round shape. In the sources of that time it is not for nothing that the word “window” is used; its diameter did not exceed 20 - 30 centimeters. In many respects, this is where the tradition of using round and semicircular windows in Russian architecture began - from the capabilities of the technology of that time.
There were similar workshops in Novgorod, Ryazan, Chernigov and many other cities. Glass jewelry was relatively cheap, they were worn by women and children, wearing several multi-colored - smooth and twisted - bracelets on one hand.
A workshop for the production of colored mosaics was found on the territory of the Kiev-Pechora Lavra. St. Sophia Cathedral in Kyiv is decorated with mosaic ornaments and images of Christ the Pantocrator and John Chrysostom. St. Michael's Cathedral, the Assumption Church in Kyiv, and cathedrals in Chernigov are also decorated.
In Kerch and Chersonese, fragments of greenish window glass were found, similar to the glass used in the thermal baths of Pompeii, Italy, and the Rhineland provinces.
The revival of glassmaking in Rus' after the Tatar-Mongol invasion dates back to the mid-11th century. In 1635, Tsar Mikhail Fedorovich gave “a charter to the Swede, the cannon master Elisha Koet, for the purchase of 16 wastelands in the Moscow district for the establishment of a glass business with the right to duty-free sale of products for 15 years and with a prohibition for others to establish similar establishments.” The Coeta plant was located in the town of Dukhanino near the city of Voskresensk (New Jerusalem). He produced “only rough glass, namely window glass and various flasks,” which were annually sent for sale to Moscow.
In 1668, construction began on a “state” (state) plant in the village of Izmailovo near Moscow (now the Moscow district of Izmailovo). This plant was already operating for export. “Izmailovo craft utensils” were exported to Persia - jugs, suleys (decanters), glasses. At the Izmailovsky plant the craftsmen were “Venitsitsy”.
The general industrial boom, which began during the reign of Peter I, also captured glassmaking. The development of glass production was caused by the great demand for glass products - window glass, mirrors, dishes, which the old glass factories that existed in Muscovite Rus' in the 17th century (Dukhannsky, Izmailovsky, Chernogolovsky) could not satisfy and the desire to abandon the expensive import of foreign glass.
Peter the Great patronized the development of glassmaking: he abolished duties on products, invited German craftsmen, and sent Russians to study abroad.
The most important role in the further development of glassmaking in Russia was played by the state glass factory, founded by Peter I in the first years of the 18th century on the Sparrow Hills near Moscow and by the mid-18th century. together with the Yamburg factories, transferred to St. Petersburg. This plant became a model for all other glass enterprises in the country, a true school for Russian glass masters and a laboratory for the development of new technology. Prominent Russian specialists in the field of art, science and technology, including M.V., took part in its work at different times. Lomonosov, T. de Thomon, K. I. Rossi, A. N. Voronikhin, V. P. Stasov, I. P. Kulibin. Russian workers, outstanding glassmakers, created wonderful works of art at this factory that amazed all of Europe and are now stored in palaces and museums.
In 1723, a unique structure was manufactured at a factory in Yamburg - a musical belfry for the Peterhof fountains, which consisted of a set of glass bells of various sizes and sounds.
In 1720, a decree “On the establishment of mirror factories in Kyiv” was issued.
During the reign of Elizabeth (1741-61), there were already six glass factories near Moscow alone. By this time, their negative sides had already become apparent - the destruction of forests in the surrounding area and water pollution. Therefore, a “Decree was issued on the non-construction of wine and glass factories near Moscow, to which there is no water communication, and on the purchase and procurement of timber and firewood for such factories from distant, rather than close, places.”
A few years later, new decrees appeared on the closure of glass factories in the vicinity of Moscow and St. Petersburg and the prohibition of building them closer than 200 miles from large cities.
Remarkable discoveries in the field of creating colored glasses and smalts are associated with the activities of the great Russian scientist M.V. Lomonosov (1711-1765).
In 1748, he organized a laboratory at the St. Petersburg Academy of Sciences, in which he conducted experiments with glass coloring, personally brewed smalt, and developed a palette of colored glass mosaics.
M.V. Lomonosov conducted fundamental scientific research in glass chemistry. Lomonosov's scientific work on colored glass had a significant influence on Russian artistic glassmaking. Factories that previously produced, in addition to white, only green and blue glass, after Lomonosov began to produce multi-colored, colorful products.
M.V. Lomonosov began working as a glass technologist and mosaic artist in the 1740s. The scientist dreamed of the revival of mosaics, intended, in his words, “for the decoration of huge public buildings,” examples of which he saw in the churches of Kyiv and Novgorod of the 11th-12th centuries.
Having done a tremendous amount of work, Lomonosov received a monopoly on the production of colored glass in Russia, for which in 1753, not far from St. Petersburg, the Ust-Ruditsk factory was founded, the designer and engineer of which was Lomonosov himself.
From the smalt welded here, Lomonosov himself and on his instructions, his students made a number of mosaic works, including the grandiose color mosaic painting “The Battle of Poltava” (1762-1764). Of his three famous works, the portrait of Peter I, kept in the Hermitage, is especially interesting.
His discoveries reach foreign countries. The factory's products, recipes, raw materials, dyes, furnaces, machines, machines and tools were constantly modified and improved. At first, only beads, glass beads and mosaic compositions (smalt) were produced. Then various haberdashery items appear: cut stones, pendants, brooches, cufflinks. Since 1757, the factory has been producing tableware, toiletries and writing utensils.
The factory paid special attention to hot glass processing. By designing special furnaces and machines, Lomonosov brought production to a high technical level. Mosaics made from Ust-Ruditsk smalts were distinguished by great technical and artistic merits. In the Chinese Palace, two tables have been preserved, as well as frames for bas-reliefs of Peter I and Elizabeth Petrovna, decoratively decorated with a mosaic of these smalts. To decorate the Oranienbaum palaces, a large amount of glass beads was produced at the Ust-Ruditskaya factory, as well as smalt for the floor in the Glass Beads Cabinet of the Chinese Palace.
Lomonosov “not only composed recipes... and hung the materials with his own hands and put them in the oven...”, but also dedicated one of his most romantic odes to glass. It’s called “Ode to Glass,” and there’s a line in it
“...I sing the praises not of gold, but of glass...”
Soon after the death of the scientist, the Ust-Ruditsk factory closed. The buildings gradually fell into disrepair and collapsed, and the two-story house in which M.V. Lomonosov lived burned down in 1919. Today, on the site of the glass factory, there is a memorial obelisk with a modest inscription: “M. V. Lomonosov lived and worked here.”
It should be noted that almost all famous Russian chemists of that time paid tribute to the study of glass. Academician K. G. Laxman (1764) proposed using natural sodium sulfate for the mixture instead of soda and wood ash.
S.P. Petukhov (1898) published the book “Glassmaking”.
I.P. Kulibin invented mechanisms for casting giant mirrors, which for a long time ensured Russia's first place in this industry in the 18th-19th centuries.
In the 16th-18th centuries, glassmaking in Russia developed both under the patronage of the royal court and on the initiative of merchants and industrialists who opened private factories.
The state (state) glass factory in St. Petersburg went through a number of stylistic stages - from the Baroque of Peter the Great to the early classics. The factory's products acquired an increasingly complex and rich character - mirrors and crystal tableware for palace chambers, Venetian and Bohemian-type chandeliers, lanterns for street lighting. With the advent of M.V. at the plant. Lomonosov, the plant began producing colored glass.
It is interesting to note that already at that time the most capable workers were promoted to positions of responsibility. Their children were assigned as students to the Mining Corps to study “chemical science” and received a salary from the plant during their studies. A school for “young workshop children” was established at the plant, where they learned to read and write and draw. Personnel for the plant were seriously trained.
The Russian tsars tried to use all sorts of diplomatic maneuvers to prevent the possibility of sharp clashes with neighboring countries. Gifts to the rulers of Asian countries played a special role, which was in the spirit of the customs of the eastern peoples. Often such gifts featured products from the St. Petersburg plant. Thus, in 1819, among other gifts, a crystal pool was sent to the Shah of Persia. The Shah liked the pool, and he wished to have a crystal bed with it to complete the set. The bed was a spacious bed located on a wide pedestal. The glass parts were attached to an iron frame lined with silver-plated copper. The flooring and steps to the lodge were made of polished turquoise glass slabs, and the side walls and armrests were made of highly intricately cut clear crystal. There were four carved crystal columns in the corners. The bed was surrounded by seven fountains in the form of crystal vases.
This precious structure was sent to Tehran disassembled. He was accompanied by the head of the expedition, Lieutenant Noskov, and two glass factory masters to assemble the crystal bed on site. It is difficult to imagine the misfortunes that these unfortunate travelers experienced: for months they rode on a sleigh and on a military transport ship, sailed on boats along a swampy river, and suffered from tropical fever. Religious fanatics almost killed the “infidels” during their holiday. While the Shah traveled around the country, they waited for him in Tehran for weeks until they died of tropical fever. Only Noskov survived. He had to assemble the box himself, guided by the drawings. The Shah graciously accepted the gift and awarded Noskov the Order of the Lion and the Sun and two cashmere shawls. Lieutenant Noskov returned safely to St. Petersburg and left interesting memories of his journey.
Due to the similarity of glass and porcelain production technologies, the factory later became the Imperial Glass and Porcelain Factory. Currently known as the Leningrad Porcelain Factory.
Another major center of Russian glassmaking was the Maltsevsky factories. In 1760, the Moscow merchant Maltsev received permission to set up a glass factory to produce “dishes, mirror, carriage and window glass.” This plant became the founder of the famous Maltsevsky factories located in the Vladimir region. The most famous plant is in the city of Gus-Khrustalny. There are many legends associated with it. The very name of the city, according to one version, comes from the name of a crystal clear river on which geese nested, and subsequently a factory was built. According to another legend, when the factory opened, craftsmen cast a figure of a goose from crystal and hung it above the gate. Since then, the goose has been the trademark of the plant.
The city has a glass museum located in the former church of St. George. The building was built according to the design and sketches of Academician L. Benois and decorated with paintings by V.M. Vasnetsov and mosaic images by V.A. Frolov.
The museum contains unique works by Gusev masters, many of which are associated with centuries-old legends.
One of them is about a glass bouquet standing at the entrance to the museum.
A century and a half ago, master glassblower Razumey Vasiliev from a family of hereditary glassmakers worked at the plant. In winter, his little daughter became seriously ill and, delirious, asked him to bring her flowers from the forest. At night, the master returned to the factory and made a glass bouquet of fabulous beauty from the remains of colored glass. Returning home, he put the bouquet on the window. In the morning the girl woke up, saw the sun playing on the glass flowers and was happy. She couldn't get enough of the flowers and eventually gained weight.
Master Vasiliev made many wonderful things - decanters with a cockerel inside, double glass goblets with landscapes of moss and blades of grass between the layers of glass, a “musical” bell vase consisting of seven plates arranged vertically, each of which reproduces the sound of one note of the octave. But his fate was sad - he was exiled to Siberia for appealing to the manager to alleviate the fate of the crystal makers.
Another dynasty - the Zubanovs - specialized in crystal polishing - “diamond drawing”. Many palaces in Russia are decorated with crystal chandeliers made by them. Even in the dark, the chandelier pendants glow with multi-colored lights - the weakest ray of light is refracted and reflected in the crystal.
In Soviet times, the Gusevsky plant, in addition to crystal and tableware, made gifts for government members, foreign celebrities and astronauts. Moreover, each such unique product was made in several copies, one of which remained in the plant museum.
Modern technologies in glass production.
The innovators of glassmaking at the end of the 19th century were artists from the northeastern region of France - Lorraine. The center was located in the city of Nancy, where three of the most interesting enterprises in Europe operate - the factories of Emile Galle, the Daum brothers and Baccarat. The style and technique of etching laminated glass developed by E. Galle created a real sensation and caused a wave of imitations, including in Russia. Emile Gall introduces opaque glass with one or two additional layers, which he decorates with engraving and a design: images of flowers, dragonflies, butterflies.
But, along with the new “modern” style, masters from all over the world also preserved the traditions of previous eras. Current or deliberately simple forms of modernity coexist with models from different times - antiquity, baroque, classicism. Artists still remain faithful to colored enamels, elegant engraving, and spectacular cutting.
The decorative arts of the early 20th century replaced the realistic and natural designs of Art Nouveau with geometric and stylized forms. In the 20th century, many new art glass factories emerged.
Since the 19th century, glass production has reached a new, industrial level. This was facilitated by numerous scientific discoveries and studies. One of the “fathers” of the glass industry can be called the German scientist Otto Schott (1851 - 1935), who studied the influence of various chemical elements on the optical and thermal properties of glass. Another significant figure is Friedrich Simmens, who invented a new type of furnace that significantly improved the quality of glass produced.
In 1910, French scientist Edouard Benedictus invented a method for producing especially strong bulletproof glass by placing a special polymer film between two sheets of glass. Such glass, known as laminated, was patented by Benedictus under the name “Triplex”.
A true revolution in the glass industry was made by the Belgian Fourcaud, who in 1905 began vertically pulling a continuous glass “sheet” of constant width from a furnace. His technology was developed in 1914. At the end of the First World War, another Belgian, Emile Bicherois, developed a process in which glass is drawn from a furnace between two rollers. Like Fourcaud's method, this method made subsequent glass polishing easier and more economical.
And finally, in 1959, the English company Pilkington Brothers Ltd. proposed a modern method for producing high-quality glass, combining the high optical qualities of polished glass and the economy of the Fourcaud method - the float method or floating tape method. Molten glass is poured into a bath onto the surface of molten tin, where it is leveled due to surface tension forces and polished from below with molten tin, and from above with hot air. This method of glass production is most widely used throughout the world today.
With the development of modern technology, fully automated factories have appeared that produce bottles and glasses, vases and vials, window and safety glass, glass hollow bricks and glass tiles, glass fiber and insulation and many other useful products. Based on glass, completely new materials with unique properties have been developed that are used in medicine, electronics and even space fields.
It is still unknown exactly who and when invented glass. It has been used since ancient times. The main components for its manufacture are soda and sand. They are found all over the planet, so it is impossible to determine the place of invention of glass from them.
Pliny the Elder (23–79 AD) wrote in Natural History that glass was invented by Phoenician merchants. They sailed on a ship from Sidon with various goods. A storm has begun. They decided to wait it out on the shore, lit a fire and wanted to cook food. Stones were needed for the cauldron. They did not find stones of the required size and decided to take huge blocks of soda that were on the ship. After preparing the food, they did not find any soda. But instead, in the fire, the merchants found an unknown substance that appeared when mixing soda with sand and exposing this mass to high temperatures. It is believed that this is how glass manufacturing technology and the necessary materials for its smelting appeared.
In the mid-twentieth century, a group of activists decided to check the accuracy of this information. Doing everything as described in the history of the invention of glass, they did not succeed. The reason, in their opinion, was the low temperature, due to which the soda did not fuse with the sand, since the necessary heat can only be obtained in the oven. Therefore, it is now generally accepted that the inventor of glass was a potter's assistant from Egypt. He dropped the hot pot into a mixture of sand and soda, and then, without cleaning it, put it in the kiln. As a result, the entire ceramic pot was covered with thin glass. This was the beginning of the appearance of glass.
According to ancient legend, the discoverers of glass were Phoenician or Greek traders. Having made a stop on an island during one of their many voyages, they lit a fire on the shore. The sand melted from the high heat and turned into a glassy mass.
The invention of glass dates back to very ancient times. Various legends about which people, where and when first made glass are unreliable, so who and when invented glass is unknown.
The appearance of glass is associated with the development of pottery. During firing, a mixture of soda and sand could get onto the clay product, as a result of which a glassy film - glaze - formed on the surface of the product.
In Thebes (Egypt) an image of glassblowers was found, a production reminiscent of our artisanal glass production. Scientists date the inscription on these images to approximately 1600 BC. e. Items found during excavations of ancient Egyptian cities indicate that Egypt was a center of glassmaking, where urns, vases, statues, columns and jugs were made.
The glass that was produced in ancient times was significantly different from modern glass. It was a poorly fused mixture of sand, table salt and lead oxide - frit. Neither the material nor the technique of antiquity made it possible to make large objects from glass.
Glass production in Egypt produced decorative and ornamental materials, so manufacturers sought to produce colored glass rather than transparent glass. Natural soda and local sand containing some calcium carbonate were used as starting materials. Low silica and calcium content, as well as high sodium content, made glass easier to melt because it lowered the melting point, but reduced strength, increased solubility, and reduced the weather resistance of the material.
In glass production, various components were mixed in clay crucibles and heated strongly in a special furnace made of refractory bricks until a homogeneous light mass was obtained. An experienced craftsman determined the readiness of the glass by eye. At the end of the melting process, the glass was poured into molds or cast in small portions. Often the glass mass was allowed to cool in a crucible, which was then broken off. The glass thus obtained was melted down and put into production as needed.
The first glass was used to make beaded jewelry. The beads were made by hand, piece by piece. A thin glass thread was wound around copper wire, breaking off the thread after each finished bead. Later, to make beads, a glass tube of the required diameter was drawn out and then cut into beads.
Vases were molded on a clay cone, wrapped in cloth and mounted on a copper rod as a handle. To distribute the glass mass more evenly, it was quickly turned several times. For the same purpose, the vase was rolled on a stone slab. After this, the rod and cone were pulled out of the product, allowing it to cool.
The color of the glass depended on the additives introduced. The amethyst color of the glass was given by the addition of manganese compounds. The black color was obtained by adding copper, manganese or a large amount of iron compounds. Much of the blue glass is colored copper, although a sample of blue glass from Tutankhamun's tomb contained cobalt. Green Egyptian glass is colored with copper, yellow glass with lead and antimony. The red glass samples are due to the copper oxide content. Milk glass containing tin and clear glass items were found in Tutankhamun's tomb.
From Egypt and Phenicia, glassmaking moved to other countries, where it reached such a development that crystal glassware even began to replace the goldware that had been used until that time.
A revolution in glass production was achieved by the invention of the glass blowing process. Later, using the blowing method, they learned to make long glass cylinders from finished glass, which were “opened” and straightened, producing flat glass. This method was used to make window glass until the 1900s, and to make glass used for artistic purposes even later.
Ancient glass products were usually painted and were luxury items that were not accessible to everyone; products made of colorless glass were especially highly valued.
In antiquity, glass did not find significant use; even mirrors were then made primarily of metal. But in subsequent eras it was used more and more often. In the Middle Ages, the use of colored glass mosaics to decorate windows in churches became widespread.
The late Middle Ages and the beginning of the modern era were marked by the widespread use of glassblowing. Glassmaking had a great development in Venice. Being the strongest maritime power in the Mediterranean, Venice conducted extensive trade with the countries of the East and West. A prominent item in this trade was glass, which was distinguished by its extraordinary variety and great artistic value. The Venetians invented mosaic glass and mirrors. Receiving great benefits from trade, Venice took every possible care to develop its glass industry. The export of glass raw materials was prohibited, and agreements were concluded with other countries to purchase broken glass from them.
Glassmakers were provided with numerous benefits. At the same time, the Venetians jealously guarded the secrets of glass production; disclosure of professional secrets was punishable by death.
Let us dwell on the main types of glass produced by Venetian glassblowers who organized production on the island of Murano near Venice.
Colored glass. Oxides of non-ferrous metals were used for its manufacture. Iron oxide colors the glass mass green, copper oxide gives a green or red tone, cobalt produces blue glass, an admixture of gold produces ruby glass, etc. The first vessels made of colored glass appeared in the second half of the 15th century. And almost all of them were painted with enamel paints. Favorite color in the 16th century. was blue - azurro. Violet glass – pavonazzo – also enjoyed great success.
The enamelled and gilded glass from Murano is of the greatest interest. The beginning of glass painting with enamel is associated with the name of the famous master and outstanding chemist Angelo Beroviero. Initially, vessels made of colored transparent glass were painted with enamel; later they began to cover milky glass with painting. Venetian vessels of the early period are distinguished by their unusually rich painting: triumphal processions, wedding processions, scenes of mythological content, and erotic subjects were depicted. Glass was often decorated with gold scale-like patterns and relief dots made of multi-colored enamel.
Transparent colorless glass was invented in the second half of the 15th century. This is the famous Venetian crystallo. The name emphasizes the colorlessness and transparency of the glass in comparison with previously produced glass of a greenish tint or colored glass.
Filigree glass. This is colorless transparent glass, decorated with glass threads introduced into the mass. These threads, usually spirally twisted, represent an infinite variety of plexuses. Most often, threads are white (milky) in color. Judging by the surviving samples, the time of the invention of filigree glass coincides with the establishment of Renaissance forms in Venetian glassmaking.
A unique type of filigree technique is mesh glass. It is made from two layers of clear glass with a filigree pattern, superimposed on each other in the opposite direction. A pattern is formed in the form of a grid, and, as a rule, an air drop is placed in each cell.
Milk glass is an opaque white glass with a milky tint ( latticinio or lattimo). It is obtained by adding tin oxide to the glass mass. The vessels of the 16th century, made of colored milk glass and painted with enamel paints and gold, were, apparently, the first attempts in Europe to imitate porcelain. Today, this fake porcelain is extremely rare and extremely valuable.
Agate glass is the name given to glass consisting of differently arranged and differently colored layers that make up patterns similar to agate. Agate glass comes in a wide variety of colors and patterns. As is known, in mineralogy, agate forms one group with chalcedony and jasper. Therefore, in old Italian treatises one can also find the names of jasper and chalcedony glass.
Aventurine glass is a special type of glass invented by Murano craftsmen at the beginning of the 17th century. On the polished surface there are countless shiny dots that produce a special lighting effect. These flickering dots on yellowish-brown glass are obtained by adding copper to the glass mass, which crystallizes when the glass cools. The invention of aventurine glass is attributed to the Miotti dynasty, which for many years kept the secret of its production.
Mosaic glass. The way this glass is made is remarkable. Multi-colored glass threads are taken and soldered into a narrow cylindrical rod, the cross section of which has the shape of an asterisk, rosette, or some symmetrical figure. This glass rod is then cut into many discs, which are inserted into the glass mass. Products made from mosaic glass are a motley field woven from stars, rosettes, etc.
Some Murano pieces are decorated with a pattern called craquelage. The pattern was obtained like this: a blown object, inside of which a high temperature was maintained, was lowered into cold water. As a result, the outer layer of glass becomes covered with countless cracks, which, however, do not penetrate into the thickness of the glass. Cracks remain on the surface of the glass, decorating it with a unique pattern.
The process of making vases using the pulegoso technique is based on the effect of air bubbles forming inside the glass, which are formed when hot glass is immersed in water and immediately returned to the furnace to give density to the substance. The vases are blown and processed by hand.
Engraved glass was already known at the beginning of the 16th century. At first, the Venetians engraved glass with diamonds mechanically. Later, a chemical engraving method was invented.
Beads. Bead production was a well-known and perhaps the most profitable branch of the Venetian glass industry. The beads were known as conterie. In a broad sense, the term conterie refers not only to beads, but also beads, glass buttons, artificial pearls, fake rhinestones and other small glass objects. The name itself is explained by the fact that this piece of goods is very easy and convenient to count (contare - in Italian - to count).
The first scientific work on glassmaking is considered to be the book of the monk Antonio Neri, published in 1612 in Florence, in which instructions were given on the use of oxides of lead, boron and arsenic to brighten glass, and the compositions of colored glasses were given. In the second half of the 17th century. German alchemist Kunkel published his essay “The Experimental Art of Glassmaking”. He also found a way to obtain a golden ruby.
In 1615, coal began to be used in England to heat glass melting furnaces. This increased the temperature in the oven.
At the beginning of the 17th century. In France, a method was proposed for casting mirror glass on copper plates with subsequent rolling. Around the same time, the method of etching glass with a mixture of fluorspar and sulfuric acid was discovered, and the production of window and optical glass was mastered.
In Rus', glass was found in the form of beads back in the 13th century, but there were no factories at that time. The first Russian plant was built only in 1634 by the Swede Elisha Koeta. The plant produced tableware and apothecary ware; the first craftsmen there were Germans, who had a great influence on the development of the Russian glass industry.
In 1668, construction began on a state-owned plant in the village of Izmailovo near Moscow, which was partially working for export. Thus, dishes of the “Izmailovo craft” were exported to Persia - up to 2000 jugs, decanters and flycatchers annually.
The construction of glass factories progressed much faster in the 18th century. Peter I did especially a lot in this regard, who patronized the development of glass making, abolished duties on glass products, ordered German masters, and sent Russians to study abroad. Upon returning from a trip abroad, he built a state-owned factory near Moscow, on Vorobyovy Gory, which was supposed to be made into an exemplary glass factory and at the same time a school for training glassmakers.
In 1720, the Decree “On the establishment of mirror factories in Kyiv” was issued. During the reign of Elizabeth Petrovna (1741–1761), there were already six glass factories near Moscow.
In 1752, “permission was given to Professor M.V. Lomonosov to start a factory for finishing multi-colored glass, beads, bugles and other haberdashery items with a privilege for 30 years.” Among the products produced at the plant was glass for mosaic work (“musiya”), from which M. V. Lomonosov created a number of paintings, including the famous “Battle of Poltava”. After Lomonosov's death, the plant passed to his widow and closed in 1798.
In 1760, the Moscow merchant Maltsov received permission to set up a glass factory for the production of crystal and glassware, as well as mirror, carriage and window glass. This plant became the founder of the later known Maltsov plants.
Until the middle of the 19th century. glass was boiled in crucibles. In the 30s of the XIX century. The first bath furnaces for industrial glass production appeared in Russia.
In 1856, Friedrich Siemens invented the regenerative glass furnace. In it, exhaust gases are heated by preheating chambers lined with refractory materials. As soon as these chambers are sufficiently hot, they are supplied with flammable gases and the air necessary for their combustion. The gases generated during combustion evenly mix the molten glass, otherwise mixing a thousand tons of viscous melt would be far from easy. The temperature in the regenerative furnace reaches 1600 °C. Later the same principle was applied to steel melting.
A modern glass melting furnace is a continuous furnace. On one side, initial substances are fed into it, which, thanks to a slight tilt of the hearth, move, gradually turning into molten glass, to the opposite side (the distance between the walls of the furnace is about 50 m). There, a precisely measured portion of the finished glass is fed onto cooled rollers. A glass ribbon several meters wide stretches the entire length of the hundred-meter cooling section. At the end of this section, machines cut it into sheets of the desired format and size for mirrors or window glass.
The next significant stage in the development of sheet glass production was the method of machine glass drawing, which was developed by Emile Fourcauld in 1902. With this method, glass is drawn out of the glass furnace through rolling rollers in the form of a continuous strip and enters a cooling shaft, in the upper part of which it is cut into individual sheets. The machine method of glass production was further improved in the first half of the 20th century. Among the most modern methods, the so-called Libbey-Owens method and the Pittsburgh method should be highlighted.
The most recent stage in glass production was the float method, patented in 1959, developed by the English inventor Pilkington. In this process, which can be equated to discovery, the glass comes from the melting furnace in a horizontal plane in the form of a flat ribbon through a bath of molten tin for further cooling and annealing. The huge advantage of the float method, compared to all previous methods, is, among other things, higher productivity, stable thickness and defect-free glass, as well as surface quality.
Among solid substances of inorganic origin (stone, metal), glass occupies a special place. Certain properties of glass make it similar to liquid. There are no crystals to be found in it. There is no sharp transition in it at any specific temperature from the liquid state to the solid state (or vice versa). Molten glass (glass mass) remains solid over a wide temperature range. If we take the viscosity of water as 1, then the viscosity of molten glass at 1400 °C is 13,500. If glass is cooled to 1000 °C, it becomes viscous and 2 million times more viscous than water. (For example, a loaded glass tube or sheet sag over time.) At even lower temperatures, the glass turns into a liquid with an infinitely high viscosity.
The main component of glass is silicon dioxide SiO 2, or silica. In its purest form, it is represented in nature by white quartz sand. Silicon dioxide crystallizes relatively gradually during the transition from the melt to the solid state. Melted quartz can be cooled below its solidification temperature without it becoming solid. There are other liquids and solutions that can also be supercooled. But only quartz can be overcooled so much that it loses its ability to form crystals. The silicon dioxide then remains “crystal-free”, that is, “liquid-like”.
It would be too expensive to process pure quartz, primarily due to its relatively high melting point. Therefore, technical glasses contain only 50 to 80% silicon dioxide. To lower the melting point, additives of sodium oxide, alumina and lime are introduced into the composition of such glasses. Certain properties are achieved by adding some other chemicals.
The famous lead glass, which is carefully polished to make bowls or vases, owes its brilliance to the presence of about 18% lead in it.
Mirror glass contains mainly cheap components that reduce the melting point. In large baths (as glassmakers call them), holding more than 1000 tons of glass, fusible substances are first melted. Melted soda and other chemicals dissolve quartz (like water dissolves table salt). This simple method can transform silicon dioxide into a liquid state already at a temperature of about 1000 °C (although in its pure form it begins to melt at much higher temperatures). Much to the chagrin of glassmakers, gases are released from the glass melt. At 1000 °C the melt is still too viscous for gas bubbles to escape freely. To degas it should be brought to a temperature of 1400–1600 °C.
The discovery of the special nature of glass came only in the 20th century, when scientists around the world began to conduct large-scale studies of the atomic and molecular structure of various substances using X-rays.
Nowadays a large number of types of glass are produced. According to their intended purpose, they are divided into: building glass (window glass, patterned glass, glass blocks), container glass, technical glass (quartz, lighting, fiberglass), grade glass, etc.
Glass products can luminesce under the influence of various types of radiation, transmit or absorb ultraviolet radiation.
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Glass has been known to mankind for many centuries. Archaeological finds prove that glass production technology was known in the Middle East as early as the 3rd century BC. Amulets and beads dating back to 7000 BC have been found in Egypt. But who and when, and most importantly for what purpose, invented this wonderful material is not known for certain.
Versions about the appearance of glass
There are several versions of the origin of glass. Some scientists believe that this material was obtained during the smelting of copper. Others prove that they obtained it by firing clay products. And according to the statements of the ancient Roman historian Pliny the Elder, humanity owes the appearance of glass to Phoenician merchants, who made fires right on the sand at camp sites and covered them with pieces of lime.
Be that as it may, for many years glass was an exquisite luxury available only to the richest and most influential. It was only with the advent of the new era, when the glass blowing tube was invented in Syria, that mass production began and glass products became more affordable, and the technology began to spread across countries. Alexandria became the most famous center for the production of glass products in the East. The ancient Romans were also considered skilled glassmakers.
Development of glass making in Europe
From the east, glass melting technology came to European countries. Here it was modified and developed to new levels. First of all, the changes affected raw materials. Soda was replaced by the more common potash.
A significant event was the invention of sheet glass in the 13th century by German masters, which was subsequently improved by the Venetians. The quality of such glass was low, it was the property of only a select few. It could only be seen in churches and castles, and now even custom-made glass doors are not a novelty for anyone.
For a long time, the largest European centers for the production of glass products were Venice and Bohemia. A technology for producing colored glass was developed. Glass blowers kept the secrets of their craft very strictly, because each area had its own technologies and manufacturing features.
In the 17th century, the primacy of glass production passed to the masters of Foggy Albion. This was largely facilitated by the discovery in the 1670s. English glassblower George Ravenscroft. He introduced lead compounds into glass and obtained an analogue of rock crystal, which was of high quality and easy to cut.
Industrial glass production
Despite the high popularity of glass products, it was only towards the end of the 19th century that their production took on an industrial scale. A great contribution to the development of the glass industry was made by:
- German scientist Otto Schott, who studied the dependence of the optical and thermal properties of glass on the composition of the feedstock;
- Friedrich Simmens invented a structurally new furnace, which ensured the production of large volumes of glass melt;
- American engineer Michael Owens. His automatic bottle-making machine quickly spread throughout the United States;
- Belgian inventor Fourcaud. The device he proposed made it possible to continuously obtain a glass sheet of constant thickness. This invention was improved by Emile Bicherois. The changes made significantly simplified the glass processing process.
Many scientists contributed their knowledge and skills to the development of glass making. Equipment has been improved, new quantitative and qualitative compositions of raw materials have been proposed, and now it is difficult to imagine the world around us without glass and various products made from it.
