Café Royal Cocktail Book by W. J. Tarling (1937, p.44)

0.13 partlemon juice — fresh lemon juiceacid
0.5 partgin — Booth's Dry Ginbase
0.25 partcuracao — blue curacaomodifier
0.13 partliqueur — creme of the skymodifier
  1. Shake.

See also: Sky