Africa’s inventions: glass-making

We all know glass, that amorphous inorganic solid substance that is usually translucent or transparent. Although glass can occur naturally, as in the case of obsidian, it is still one of the oldest and most important man-made materials in the world. There are hundreds, probably thousands, of types of glass, with their different colours and textures used to make a gazillion things.

Today glass has become so common and infused with our daily lives that it would be difficult living in a world without it. There is no mistaking the role of glass in our life. Just one look around you right now, and you’ll be sure to find some. . . . thing that is glass.

Can you imagine a world without glass? One could make a strong case that modern advances as we know it today, might not have been attained without it. Glass affects every part of lives; science, industry, work, home, play, and art. So many things, from screens, light bulbs, eye spectacles, thermometers, bottles, solar panels, to microscopic slides are all made from glass, the list is endless!

When it comes to the application of glass, it’s obvious the uses are numerous.

Glass with different textures (Source: public Domain)

Humanity’s usage of glass dates back to ancient times in Egypt and Mesopotamia. Then, it was primarily just used as a practical and decorative object. Today, our use of glass has evolved to become an essential part of our daily lives, so much that we very often fail to even notice.

Let’s take a look at just a few examples of what we use glass for today.

Fibre optic cables, the backbone of the high-speed internet we enjoy today is a product of glass.

Zoomed in image of a glass fibre-optic cable (Source)

Glass is used in radiation shielding, for protection from radiations like X-rays or Gamma-rays. Even though sometimes, the combination of glass with other materials may be better, glasses with a high number of metal oxides have been known to provide better shielding against ultra-high radiations.

Glass is used in harnessing energy from renewable energy sources, such as solar panels and wind turbines.

Medical and engineering technology often require glass, in applications such as optical glass, for biotechnology, and as electronic components.

You can’t talk about present-day use of glass without talking about its use in construction – for parts such as balustrades, partitions and windows; in aesthetics; in the automotive and transport industry – for parts such as windscreens, backlights, mirrors – ; in household products, such as oven doors, TVs, computer screens, smartphones; and a million other products.

There won’t be enough space here if we are to mention all of the uses of glass; its usefulness to modern society cannot be overemphasized!

The Origin Of Man-Made Glass

So how did man-made glass even come about? Tracing back to the very origins of glass-making 2 names always pop up in all of the records; Egypt and Mesopotamia. Although it’s not clear exactly which of the two actually invented glass-making, it is, however, clear that not only was Egypt involved from the very beginning but unlike Mesopotamia, Egypt was also largely responsible for the spread of glass-making technique to the different civilizations of the world. This is a strong indication that Egypt might have in fact invented glass-making, or perhaps, we can assume that there was a phenomenon of convergence, and glass-making was discovered independently in both Asia and the Nile valley.

Ancient man-made glass beads (Source: Public Domain)

Man-made glass-making has been traced to around 3,500 BC. Man-made glass objects (mainly glass beads) were discovered in both Egypt and Mesopotamia dating to this time. Although it is very likely that glazing, a technique central to glass-making, might have also been familiar to Mesopotamia and also the civilizations of the Indus at that very early time, no evidence indicates that they ever spread their knowledge abroad.

By the second Millennium before our Era, around 2500 BC, glass finds had started to occur more frequently but were still primarily concentrated in Egypt and Mesopotamia. During this period, glass made products were still rare and considered precious and its use was largely restricted to the elites. Glass vessels were an uncommon product at the time.

From 1600 BC the art of glassmaking began to spread. Around this time, different glass vases of different shapes and sizes were all produced by Egypt, from the graceful stemmed chalice vases, down to vases that were made after the form of fishes. Some of the glassworks survived, and can still be seen today. Such as the glass bottle, bearing hieroglyphs of Pharaoh Thutmose III that is on display at the British Museum.

The Egyptians were also known to embellish objects from other materials with glazes of glass. The glass products were usually polychromatic but always opaque.

It wasn’t until around 1300 BC under Tutankhamun that transparent glass made its appearance.

1st AD Roman mould-blown glass bottle from Syria (Source)

By 700 BC, alabaster – a form of Egyptian polychromatic vase – was widespread all over the Mediterranean. It was around that same time that the art of glass-making was copied by the Phoenicians (present-day Lebanon), who built the glass-making art into a large industry, and from there the art spread to Cyprus, Greece, and the Italian peninsula. It was also the Phoenicians that later discovered how to blow glass with blowing iron sometime around the beginning of the Christian era. This became a very significant advancement in glass-making. Not only did it pave the way for humans to be able to mould molten glass into whatever desired shape or size, but it also made possible for the first time, new commercial applications of glass and resulted in the creation of high-quality glass products. Much of our modern glass blowing technique relies on this breakthrough.

The Pharaonic glass making techniques were later handed down to craftsmen during the Hellenistic period. It was these men that invented brown glass.

Alexandria in Egypt was renowned all over the world as the home of glass-making, and they exported their products all over the world to as far as China.

After the conquests of Alexander the Great in the 4th century, glass-making knowledge spread to the east including the Indian subcontinent. This is probably when the characteristic glass beads and bangles associated with the Hindu culture was birthed.

Also, around this time, there is a record of Roman Emperor Marcus Aurelius imposing taxes on glass products imported from Alexandria.

The Meroitic Empire also imported glassware from Alexandria, learnt the Egyptian glass-making technique and spread its knowledge up to the upper Nile valley.

Glass In The Modern World

The introduction of man-made glass to society has no doubt been of immense benefit to humans. There is no mistaking the heavy reliance on glass today by society. Glass is very durable, nonporous and doesn’t retain odours. One impressive quality of glass is that it is 100% recyclable, and can be recycled infinitely without any loss in purity nor quality.

The driving force behind the widespread use of glass can be attributed to its low production cost despite its unlimited options in terms of manufacture and use.

The art of glass-making continues to advance, new techniques are still being discovered that makes glass production faster and better. More advanced uses of glass are also being discovered, especially in computers, medical devices and communications. There are talks of smart glasses which react to outside stimuli. Photochromic glass, thermochromic glass and electrochromic glass reacts to light, heat and electricity respectively.

All of these accomplishments would not have been possible without the early glassmakers, we owe them a debt of gratitude for their early works which have led us to where we are today.

SOURCES

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