The patent. US 618,428, "Candy-Machine", granted 31 January 1899 to William J. Morrison and John C. Wharton of Nashville, Tennessee. Morrison was a dentist — and also a lawyer, an author and president of the Tennessee State Dental Association — and Wharton was a confectioner. They introduced the product as "Fairy Floss" at the 1904 St Louis World's Fair, selling around 68,000 boxes at 25 cents each, roughly half the price of admission to the fair itself.

Why sugar can be spun and most things cannot. Molten sucrose cooled quickly does not crystallise; it passes through a glass transition into an amorphous solid. A material that crystallised on cooling would form ordered grains and fracture rather than draw into a filament. This is precisely the property exploited in glass fibre and in melt-spun polymers, and it is why the patent's phrase "silk-like filaments" is more accurate than it sounds — the process is closer to fibre spinning than to confectionery.

Centrifugal extrusion, and why it must be hot at the rim. Rotating the melt drives it outward with a force proportional to ω²r, forcing it through fine perforations. Each emerging thread has an enormous surface-area-to-volume ratio, so it loses heat and solidifies within a few centimetres — which is what allows the product to be collected as a dry web rather than a syrup spray. The failure modes follow directly: a rim below the melting point blocks its own holes, and a collecting bowl too small catches threads before they have solidified.

The hygroscopy is not a flaw in the process. Amorphous sugar readily absorbs atmospheric moisture, and floss has perhaps a thousand times the exposed area of the same mass as a lump. It therefore takes up water, softens and collapses within hours in humid air. No amount of improvement to the machine changes this; it is a property of the material and its geometry, and it is the reason cotton candy is a fairground product made in front of the customer rather than a packaged one.

Candy

Blueprints (2)

Cotton Candy Machine

Honeycomb Toffee