The Police Gazette Bartenders Guide by Richard K. Fox (1888, p.40) — 1888

1 piecelemon peel — lemon rindacid
0.5 wine-glassIrish whiskey base
0.5 wine-glassScotch whisky — Scotch whiskeybase
2 wine-glasshot water — boiling hot waterdilution
1 teaspoonfulsugar — sugarsweetener
  1. Put the Irish whiskey, Scotch whiskey, sugar, and lemon rind into an earthen mug.
  2. Add the boiling hot water and serve.

Garnish: Lemon rind

Summary
A split-whiskey hot mug that keeps mixed-whisky winter service visible in a practical regimental form.

This is useful because it records mixed Irish-and-Scotch hot service explicitly instead of assuming a single-whisky default.

The earthen mug is a meaningful vessel choice and should stay attached to the service.

Compared with the single-spirit hot whiskey punches, this is a deliberate crossover branch.

Bartenders' Guide: How to Mix Drinks by Wehman Bros. (1912, p.57)

3 dashlemon juice — Lemon juiceacid
0.5 wine-glassIrish whiskey base
0.5 wine-glassScotch whiskey base
2 wine-glasswater — Hot waterdilution
1 teaspoonsugar — Sugarsweetener
  1. Combine the whiskeys, sugar, lemon juice, and hot water and serve.

Ice: Ice

See also: Hot Irish Whiskey Punch, Hot Scotch Whiskey Punch, Half and Half