Daly's Bartenders' Encyclopedia by Tim Daly (1903, p.62)

1 pony glassbrandy base
1 bottleclub soda — Fill up the glass.dilution
1 small lumpice — Source says one or two small lumps.other
  1. Build the brandy, ice, and club soda in a medium thin bar glass.
  2. Fill up the glass and divide equally into two star champagne glasses.

Ice: 1 or 2 small lumps

Daly's morning-bracer note is useful evidence for everyday functional drinking remaining part of bar literature.

The unusual split service into two glasses is the defining structural feature.

See also: Brandy Float, High Ball