![man-made-glass](https://i0.wp.com/www.u3amoraira-teulada.org/wp-content/uploads/man-made-glass.jpg?resize=1024%2C438&ssl=1)
By John Hopwood.
Briefly describes the various types of naturally occurring glasses and then follows with some in-depth discussion of how glass was first discovered, how it became a wonderful art form as well as a highly technical product with some interesting illustrations throughout.