Even nowadays not known for sure how glass was invented. There are many legends related to the invention of glass, but only of them seem to be relatively plausible. The most important is the glass jars and glass bottles won't be used nowadays without inventing the glass.
In this version, glass was accidentally invented, being a by-product of pottery manufacturing. It is well known for firing clay to give it strength which was carried out in sand pits. For firing in those times they were using reed or dry straw. As of high temperatures, the sand was interacting with the main combustion products. As a result of this action was forming a transparent fast-setting mass. Another common version of the origin of glass is the formation of a by-product during the smelting of copper. Some scientists believe there is a third version of the glass origin. In their opinion, glass formed as a result of the interaction of high temperature on the sand and African mineral soda. By this version, Phoenician merchants during stops on the seaside cooked food on the hearth from African mineral soda.
Another dispute between scientists is the geographical origin of glass. They all agreed that it was accidentally invented about 6000 years ago, but where? According to various sources, glass originated in the Eastern Mediterranean, Mesopotamia or Phoenicia. The first glass makers no doubt were Egyptians. They were creating glass products in special clay containers. The fritting method was also invented at that time: hot pieces of glass were dipped in cold water, ground to dust and melted down again. This glass production type has been used for many centuries.
The ancient furnaces used to make glass were built from alumina and stones. Their only drawback was the high consumption of firewood. This is not surprising, because inside the furnace it was necessary to maintain a consistently high operating temperature - up to 1200 degrees, and for melting it was necessary to melt the furnace to 1450 degrees. Soda, ashes of various plants and sand were used as raw materials for the manufacture of glass. Many centuries ago, craftsmen learned how to make not only white but also colored glass. In those days, it was customary to use various metallurgical slags as dyes, compounds of manganese, copper and cobalt. The ancient furnace was a low vault, under which clay containers were placed for melting glass. The surrounding forests served as fuel for such stoves, so when they were completely cut down, the furnace had to be moved to another place. In ancient times, glass melting was a very laborious and time-consuming process, resulting in very high prices for glass products.
The heyday of glassblowing began with the Roman Empire. But after the great empire collapsed, glass production developed very slowly. Subsequently, the glassblowing business was divided into two directions: western and eastern. For a long time, the methods of glass products manufacturing remained the same, only the technique was improved. The first changes in the technique of creating glass appeared at the end of the 1st millennium. After a series of experiments, it was possible to partially change the raw materials, but maintain the high quality of glass products. European masters replaced soda with potash, which was obtained by leaching the ashes of coniferous and beech trees. After the replacement of raw materials, the Mediterranean and European products have even more differences.
The leadership in the manufacture of sheet glass belongs to German glassblowers. Back in the eleventh century, they had the idea of blowing a hollow cylinder, cutting off its bottom, and then rolling the material into a thin sheet, giving it a rectangular shape. Italian craftsmen began to use this technique only in the thirteenth century. Of course, the quality of medieval glass cannot be compared with modern glass, but the same raw materials are still used to produce glass products. Having mastered the improved technology of glass production, European masters for the first time begin to make stained-glass windows, to create which pieces of colored glass are fastened together with metal alloys.
By the end of the Middle Ages, Venice became the center of glass-blowing production. Glassmaking here has gained incredible popularity, in a few years more than eight thousand glassblowers worked in Venice. However, very soon Venetian glass was forced to give way to crystal, which was initially made only by English glassblowers. According to historical facts, the crystal was invented by George Ravenscroft, who was the first to use more advanced raw materials. Instead of potash, the inventor used lead oxide, resulting in a beautiful glass with perfect reflective properties. Moreover, the crystal was easy to detail and finely engraved, so such glass soon found itself out of competition.
Industrial production of glass began relatively recently - only in the nineteenth century. There are many glass jars or glass bottles factories all over the world. The biggest are in Germany, the United Kingdom, Russia and France.