Shake all the ingredients with ice and strain into a chilled martini glass.
Modified from a recipe in The Artistry of Mixing Drinks by Frank Meier, 1936 (Ritz hotel, Paris). Port was a popular ingredient in punches and cocktails, sometimes as a float and sometimes shaken into the drink. (See the Port Cobbler and the Port Whiskey Punch.) Many of the drinks in the cobbler section, with the exception of the Champagne Cobbler, would be improved with a float of ruby port.