Cardini-owned Multiplying Billard Balls

Cardini (Richard Valentine Pitchford). Multiplying Billiard Balls owned by Cardini. American [?], ca. 1940. Set of three turned 2” wooden balls and matching shell painted white, in a fitted cloth-lined case. Paint worn, else good. A letter of provenance accompanying the billiard balls traces their ownership, from Cardini to Larry Jones, a magician and collector, to Dr. Robert Escher, to the current owner. The balls were likely not used by Cardini, but owned by him.