About Town Cocktail Book by Joe Fitchett (1925, p.24) — About Town 1925

1 portionrye whiskey — Ryebase
1 portionFrench vermouth — French Vermouthmodifier
1 portionItalian vermouth — Italian Vermouthmodifier
  1. Mix with ice to taste and serve.

Ice: Ice to taste

This matters because it preserves a social-book equal-parts rye-and-vermouth branch close to the Manhattan field.

The source gives only ingredients and ice, so the service is preserved conservatively.

See also: Manhattan Cocktail, Perfect Cocktail