Billiard balls have a long and destructive history. At the beginning, they were made of wood, and the only thing they could damage was themselves. Let's just say that after a few games the balls didn't look much like balls and you could hardly tell the colored balls from the white ball.
Later on, billiard balls were made of ivory. It means that for every set of billiards balls you had to kill about 2-3 elephants. Not that the anyone cared about the elephants lives, the main problem was that the elephants' hunters lives were risked at the process.
Later on, a special composition called cellulose nitrate composed the billiard balls. Though its inventor, John Wesley Hyatt was induced to the Billiards Hall of Fame, the preparation of the billiards balls materials was explosive. Literally.
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