About Town Cocktail Book by Joe Fitchett (1925, p.29) — Optional Rum

4 tablespoonfulsgrapefruit juice — Grapefruit Juicebase
rum — Add as much rum as desired.base
ginger ale — Ginger Aledilution
1 teaspoonfulGrenadine sweetener
2 tablespoonfulsSugar syrup — Sugar Syrupsweetener
  1. Pour the grapefruit juice, grenadine, and syrup on chopped ice in tall glasses.
  2. Fill with ginger ale, stir, add rum as desired, and garnish with a cherry.

Garnish: Cherry

Ice: Chopped ice

This matters because it preserves a temperance-adjacent long drink whose alcohol is optional rather than fixed.

See also: Gin Rickey, Emergency Punch