Back in 1944, LIFE Magazine ran a series of photos showing some of the hand signals used by club owner Sherman Billingsley to communicate with his staff while he schmoozed with a customer.

In a similar vein, the general manager of Eleven Madison Park demonstrates some hand signals used in his fancy restaurant.

I’m fascinated by hand signals and more generally the mechanisms by which complex processes are coordinated, particularly the subtle mechanisms that customers never notice.

For example, when I visit a casino, I like to hang out near the craps table, not because I enjoy the game itself, but because I enjoy watching how the people who manage the table keep track of dozens of bets simultaneously.

Bonus reading: The secret codes used in fancy restaurants, the mechanics of Fashion Week, and how the Queen signals her attendants at social events.