How were stone cannon balls made?

Stone canon balls, or shot, were made by hand by an experienced stonemason. The process was, and still is (can be made for living history demos but not fired ), a time consuming job. Material would have been any hard natural stone that was available, usually sand stone but sometimes granite. The stone would be hand worked to small radius sections and then rubbed up with a stone block. A reverse section template would be used for accuracy.