With a mechanical slot machine I can understand the reel thing But

1933 Mechanical Slot Machine Restoration mechanical slot machine gambling devices , alias circus machines , Numbers 542 , 553 , and 535 mechanical slot machine was intro- duced in evidence and observed in mechanical orange slot A slot machine, fruit machine , poker machine or pokies is a gambling machine that creates a game of chance for its customers

mechanical slot The mechanical slot machine is an iconic symbol of the gambling industry and has undergone significant transformations since its inception