Spray-On Glass

[Darlica]

Both are indeed common myths...
And the glass one is still told, I have corrected guides who work professionally guiding people in and about historical buildings...

These large glass cylinders L is talking about can still be found on auctions and yard sales here (mostly in the south of Sweden), most of the time they are seen as quite mysterious items as no one usually knows their purpose. Usually the glass in these have air bubbles or some other defect that rendered them useless for windows but of some unknown reason they didn't got smashed and remelted.

IMHO glass is one of the most fascinating materials we have and I would love to try to work with it sometime.