Sand + Soda + Lime + A hot, hot fire = Glass

The first indication that humans were actually making glass is a clay tablet, dated around 3300 BCE, with instructions on how to build a glassmaking furnace. By the 13th Century, Egyptian glass was more famous than its Mesopotamian predecessor. Here's a picture of King Tutankhamun's death mask. Glass is inlaid to look like lapis lazuli (although lapis is also used), and this was not an uncommon use. The Egyptians emulated gem stones, made perfumeries, and fashioned decorative bottles all out of glass.
In the 1st Century BCE, the art of glass blowing came into practice. Now glass was malleable--it's versatility now evident. The Romans, of course, jumped all over this.
From Glass Act™
...one clever Mesopotamian managed to form a glass tube and blow a bubble at the end, creating the first blowpipe and hence the art of glassblowing. The first metal blowpipe came into widespread use in the 1st or second century before Christ and glass production soared, particularly in the Roman world, where glass became available to the rich and the poor.

Windows of the Soul
Other than King Tut's eyes, the first glass windows were discovered in Pompeii. So let's head to Rome. This is from British Glass:
Around 100AD, the Romans discovered that adding manganese dioxide to their glass mixture created clear cast glass, hence the could use it for window glass . . . The glass composition used by the Romans is almost identical to that used in the modern world.


More Window Talk
The first known Anglo-Saxon stained glass (7th C.) was found in Yarrow. The Romans had used it in their villas several hundred years earlier. The Normans first started using windows in their buildings in 1180. As you can see, the technology ebbed and was re-discovered several times.
In 1266, a Franciscan monk named Roger Bacon wrote the uses of plano-convex glass to magnify. Glass became even more useful--lenses were added to the glass hit parade, although I have to wonder if anyone used them for eyeglasses at that time.
Better, bigger windows were a sign of Tudor times (Hampton Court), as well as hourglasses used aboard ship, and timepieces--the height of elegance. Elizabeth I wore a pendant timepiece.
The next century (we're in the 1600s now) brought telescopes and microscopes. In 1674, George Ravenscroft substituted lead oxide for the clear lime in the glass mixture and voila! Lead crystal.

And we still are in awe of the beauty of glass. Here's Dale Chihuly with some of his work at the Tacoma Art Museum (Washington). He does awesome work. If you ever get a chance to see one of his displays, please don't hesitate!
Jacquie

Jacquie Rogers
Faery Special Romances (May 2007)
Take a look at the book video
Royalties go to Children's Tumor Foundation,
ending Neurofibromatosis through Research