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

0.11 partlemon juice acid
0.33 partgin — Booth's dry ginbase
0.11 partcuracao — blue curaçaomodifier
0.33 partdry vermouth — Noilly Pratmodifier
0.11 partGomme syrup — gommesweetener
  1. Shake.

See also: Fitzbeck