Café Royal Cocktail Book by W. J. Tarling (1937, p.153)

0.25 partlemon juice acid
0.25 partgin — Booth's dry ginbase
0.25 partScotch whisky — Scotch whiskybase
1 dashsweet vermouth — Martini sweet vermouthmodifier
0.25 partCointreau other
  1. Shake.

Invented by H. G. Yarrow.