The first double played, which is turned sideways in the line of play and allows for play in all four directions
Anyone operating the spinning machinery, which was installed in long rows, each row having two "sides." Thus, a spinner responsible for "eight sides" was actually in charge of four long rows of machinery.
The first double that is played during a game is called the "spinner". In many games, dominoes can be played off all four edges of the spinner - both ends and both sides.