Pool Table Balls
The earliest version of pool was played outdoors. At the time pool table balls were made of stone, but once pool became an indoor game, pool balls were changed to hard rubber or wood. Wood was more common as it was easy to shape, plentiful and inexpensive.
In the 1600s brass and ivory pool table balls were introduced but they were scarce because the cost of ivory only permitted that the wealthy could afford them. Ivory balls weren't very dependable, and the process to make one could take up to two years as the tusk had to be properly seasoned. A rich and glossy finish was present on ivory pool table balls, coming from the gelatin present in the tusks. Ivory was also a source of moisture, and unless the balls were properly dried they often split or cracked due to temperature changes. Ivory pool table balls had to be broken in gently, and even then they quickly lost their shape when involved in high impact games of pool.
Even with all of their faults, ivory balls had more or less replaced wooden ones by about 1800. The demand for ivory pool table balls led to the deaths of many elephants, as one tusk only produced about four or five balls. Ivory to make pool table balls had to be cut from the middle of the tusk in order for them to roll properly. The price of ivory skyrocketed as the demand for pool table balls grew, and the elephant population dwindled. It was also becoming harder to manufacture ivory pool table balls of exact weight, size and density. Ivory balls were eventually outlawed in 1970 because of the massacre of elephants.
In 1863 a New York firm offered $10,000 to anybody who could produce a suitable replacement for ivory pool table balls. In 1869, an American chemist named John Wesley Hyatt unknowingly produced the world's first plastic pool table ball when he mixed nitrocellulose with camphor under high pressure to form celluloid. Previous to this, Hyatt had coated the balls with a substance called callodian, but they shattered on impact because the inner weight of the ball was too heavy. Celluloid was now used to coat pool table balls or to completely construct, them but reviews of the new pool table ball were mixed. In the early 1900s, artificial plastics made of bakelite and cast-phenolic resins were introduced, and these are still the main components of pool table balls today.