Another use for marbles used to be in photography.Dave wrote:Decorators cribbed the idea from scientists, who came up with these many years ago. Google-search "boiling beads". They were (and are) used in laboratories, in beakers and flasks that are being heated. By providing surfaces with lots of minute irregularities that act as nucleating sites, they ensure that the liquid comes to a gentle bubbling and gradual simmer when heated. Without them, a liquid can "superheat" without boiling, and then suddenly flash over and spew boiling liquid everywhere... messy and dangerous.
When i was six or so (1954), i asked my mother why we had so many boxes of marbles around the house.
She explained that she and my dad had done a lot of photography, including their own darkroom work (as a matter of fact, i wish i had a copy of my birth announcement, which featured photos of all three of us - them with the Miniature Speed Graphic - and was designed as a studio announcement of a new production...).
Some solutions were prone to oxidation in storage, so as you used them, you would add marbles (which, being glass, were inert) to bring the level in the half-gallon or gallon bottles up to the point where its surface was in the neck, to minimise surface area for atmospheric interaction.
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Then, of course, there's Campbell's Vegetarian Vegetable and Marble Soup. Only available to studios producing commercials.
(The page's summation of the case is wrong - it was not a competitor who sued Campbell's, it was the FTC, and they got onto it because an ad agency copywriter, testifying before the Commission on an unrelated matter, let it slip that they did it.)
My 
