Raspberry and Honey

A fountain drink in three lines: a blended syrup, two ounces of it, and cold carbonated water. The whole trick is in the pouring.

• The syrup, decoded"Maple Syrup / Honey / American Raspberry Juice, equal parts" means a compound syrup mixed in advance and held in the tank. Make a cup at a time — roughly 1/3 cup each of maple syrup, honey and raspberry syrup or strained juice — and keep it refrigerated.
• Raspberry juice was not plain juiceRaspberry juice was often not plain juice -- Fountain "fruit juice" of this period was frequently a sweetened, preserved syrup rather than a fresh pressing. Unsweetened fresh raspberry juice will read thin and tart here; a raspberry syrup, or juice cooked down with sugar, is a plausible match for the intent.
• Proportions2 ounces of syrup to a 10-ounce tumbler is about a 1:4 ratio — richer than many modern Italian sodas. Scale to 1 to 1 1/2 ounces if you want it drier.
• "Drawing quietly with large stream only"This is the hinge. The fountain draught arm offered a coarse stream and a fine stream; the instruction is to use the heavy stream alone, which suggests the drink was to be filled without whipping up a foam. With a siphon or a bottle, tilt the glass and pour steadily down the inside wall.
• Stir gentlyHoney is dense and will sit at the bottom. One or two slow turns with a long spoon is enough — vigorous stirring drives off the carbonation the drink depends on.
• TemperatureNo ice is called for because fountain water ran through a cooling coil. Chill both the syrup and the soda water hard beforehand; ice added to the glass will dilute a drink already built to a fixed ratio.
• YieldOne 10-ounce glass. A cup of the compound syrup makes about four.
• The last line"Keep a tempting list of flavors in plain sight" is instruction to the dispenser, not to the cook — a note about display, aimed at the man behind the counter.