Where Did Highballs Come from?

Why do they call drinks highballs?

Etymology. The name may refer to the practice of serving drinks in tall glasses, on the dining cars of trains powered by steam locomotives, where the engine would get up to speed and the ball that showed boiler pressure was at its high level, known as "highballing".

What does Highballs mean in The Great Gatsby?

highball. a group of drinks that involve an alcoholic based spirit with a non-alcoholic mixer (e.g. gin and tonic, rum and coke) - Gatsby chooses highballs at the speakeasy, which reflect him as the soft drink represents his humble side while the spirit is his grandiose appearance)