Café Royal Cocktail Book by W. J. Tarling (1937, p.210)
| 0.3 part | Calvados — Calvados (Un Trou Normand) | base |
| 0.4 part | gin — Gin | base |
| 0.2 part | grapefruit juice — Grapefruit Juice | garnish |
| 0.1 part | van der hum — Van der Hum (Sedgwick) | modifier |
- Shake and strain.
Invented by Tony O'Connor.