watch ball

A witch ball is a hollow glass sphere, sometimes up to 7 inches in diameter, and often made in colors like green and blue. The term may be a variation of the older term "watch ball". While references to witch balls date back to the 18th century, their origins are likely older. They share similarities with glass balls used by fishermen for nets and have been linked to sea superstitions. It's also suggested they were hung in windows to ward off bad luck. Later versions, made from the mid-19th century, were silvered inside and used for their reflective qualities, similar to a convex mirror. Witch balls are collected as curiosities, and modern versions are still produced.1