Define The Term Safety Glass.

As evident from its name, safety glass is glass that has been strengthened or secured.  There are two kinds of this protective glass, both of which were discovered by accident.
The types are namely laminated safety glass and toughened safety glass.

It was in the early 1900's that a French chemist Edouard Benedictus accidentally dropped a glass flask on the floor.  To his immense surprise, although the glass cracked and starred but it didn't break.  After a careful examination of the flask to determine the reason for its intact condition, the chemist discovered that a coating of dried celluloid, which was inside the flask had held the broken glass fragments together.

In the seventeenth century, Prince Rupert, who was the nephew of King Charles 1 of England, discovered that molten glass, if tipped into cold water turns into eminently tough pear-shaped drops.  Those drops were later referred to as Prince Rupert's drops, which can be hammered on an anvil without breaking but if the tail of the drop is broken, then those drops crumble into dust.