Preparation To make ice block, fill carton with water and freeze until solid, about 8 hours (see cooks' note, below). Stir together sugar and 31/2 cups water in a large bowl or pot until sugar is dissolved. Add lemon juice, rum, Cognac, and brandy and chill, covered, at least 3 hours. Put ice block in a punch bowl and pour punch over it. Cooks' notes:• For a clearer ice block, boil water first, then cool to room temperature. •Punch can be chilled up to 6 hours before adding ice.
Preparation To make ice block, fill carton with water and freeze until solid, about 8 hours (see cooks' note, below). Stir together sugar and 31/2 cups water in a large bowl or pot until sugar is dissolved. Add lemon juice, rum, Cognac, and brandy and chill, covered, at least 3 hours. Put ice block in a punch bowl and pour punch over it. Cooks' notes:• For a clearer ice block, boil water first, then cool to room temperature. •Punch can be chilled up to 6 hours before adding ice.