Cheerio! A Book of Punches and Cocktails by Charles (1928, p.15)

1 fruit portionorange or lemon juice — One orange or one-half lemon.acid
1 partdry gin base
1 partJamaica rum base
1 dashbitters bitter
ice — For shaking.other
  1. Place the Jamaica rum, dry gin, citrus juice, bitters, and ice in a shaker.
  2. Shake thoroughly, strain into a glass, and serve.

Ice: Ice

See also: Jamaica Glow, Havana Special Cocktail

Source allows either one orange or one-half lemon.