From the 17th century to the early 20th century what was the main material used for billiard balls?
Billiard ball Billiard ball A billiard ball is a small, hard ball used in cue sports, such as carom billiards, pool, and snooker. The number, type, diameter, color, and pattern of the balls differ depending upon the specific game being played. Various particular ball properties such as hardness, friction coefficient and resilience are important to accuracy. Early balls were made of various materials, including wood and clay (the latter remaining in use well into the 20th century). Although affordable ox-bone balls were in common use in Europe, elephant ivory was favored since at least 1627 until the early 20th century; the earliest
Immigration from China in the early 20th century these nationals to work legally. More than 80,000 Chinese immigrants were affected by this act. Having the right to work and live legally in the United States prompted many immigrants from Hong Kong and Taiwan to pursue jobs in the United States. In the late 1990s through early 2000s, there was a significant influx in employment for Chinese laborers, according to census data analysis. Immigration from China in the early 20th century Significant Chinese immigration to the United States began with the California Gold Rush, in the late 1840s. Many of these immigrants were single men who worked for a