Café Royal Cocktail Book by W. J. Tarling (1937, p.89)

1 dashAngostura bitters base
0.5 partbrandy — cognac brandy or rye whiskybase
0.5 partFernet — Fernet Brancaother
2 dashessyrup — plain sugar or gum syrupsweetener
  1. Stir, strain, and squeeze lemon peel on top.

See also: Fernet Branca