By the 1100s, glass-making was expanding again from West Asia; there were glassworks further east at Kuva in Central Asia (modern Uzbekistan). Glass-making also moved westward: by 1000 AD, Venice was a growing center of glass manufacturing. In northern Europe, glassmakers figured out how to make glass using local wood ashes instead of imported burnt plants, which made glass much cheaper there.
The first eyeglasses
As Europe’s climate improved in the 1200s, Europeans got richer and more educated, and more people started to read, people in Italy began to use reading glasses about 1286 AD. In northern Europe, glassmakers made beautiful stained glass for cathedrals. Then, in the 1300s AD, North Africa and West Asia lost control of world trade to Europeans. In the 1500s, Indian traders also lost control.
Mirrors and beads
While West Asia and India became too poor to pay for schools and books, Europeans were rich enough to spend money on education and scientific experiments. By 1550, Venetian glass-makers were making good mirrors, which they sold for a lot of money. Venetian glass-makers also made tons of pretty glass beads, which European traders sold to Native Americans and Africans in exchange for furs and people to enslave.
Telescopes and greenhouses
But, thanks to that same slave trade and colonization, Britain and France became richer in the 1600s. British and French glassmakers had the money to experiment, and they figured out better manufacturing methods like lead crystal and pouring molten glass instead of blowing it. They also made the first telescopes. By the 1700s most glass-making moved from Venice to Britain and France. About 1800, glassmakers began to use steam engines to do a lot of the work, so big sheets of flat glass became cheaper. People started to have glass in their windows at home. Architects even built railroad station roofs out of glass! Glass greenhouses made it possible to grow vegetables in the winter.
Glass skyscrapers and computers
Soon everybody wanted glass for everything. French glassmakers began rolling glass on big iron tables in the 1830s. Then the British Henry Besemer figured out how to roll out a continuous ribbon of glass in the 1840s. British glassmaking got more and more mechanized. By the 1960s, British glassmakers invented modern float glass, where instead of iron rollers the glass is poured onto a river of melted tin. With this glass, you could build whole skyscrapers out of glass and steel. But since World War II Britain is poorer, and most glass isn’t made in Britain anymore. Today, China makes than half the world’s glass, used for everything from computer screens to car windows and solar panels.
Learn by doing: scratch the backing off an old mirror to see what happens
More about Venice
How Glass Is Made, by Alan J. Paterson (1985). Easy reading, but it’s really about modern glass technology.
Studies in Ancient Technology: Leather in Antiquity – Sugar and Its Substitutes in Antiquity – Glass, by R. J. Forbes (2nd revised edition 1997). Only part of the book is about glass, but it will tell you everything you need to know about glass in ancient Greece and Rome. By a specialist, for adults.
Early Glass of the Ancient World: 1600 B.C.-A. D. 50, by E. M. Stern (1995). Marianne Stern is the leading world expert on ancient glass.
Roman, Byzantine and Early Medieval Glass: Ernesto Wolf Collection, by E. M. Stern and others (2002). Same expert author as above.