Hearn's Cocktail, as printed in The Old Waldorf-Astoria Bar Book, 1935, a collection of Pre-Prohibition, Classic Cocktails.
Hearn's
Add to iced tumbler, shake and strain into a cocktail glass:
1 dash of Manhattan Bitters
1/3 whiskey
1/3 Italian vermouth
1/3 absinthe
The Old Waldorf-Astoria Bar Book