And I found the piece I was looking for (thought I'd saved it somewhere):
What I do know, is that the German transperants, and -opaques, ( slags as some of you call them) where made in Lauscha, because that's the reassson you can find them in the museum there. These marbles were one of the first machine mades in Thüringen. About the German sparklers, I think that name is totaly wrong, should be European Sparklers. I only found a few of my collection in Germany, while I was there, the rest of it, I've found in France, every summer we have holliday in France and of course I did my homework there. For me it is 100% sure that the European Sparklers were also made in France, and I think most of them. In the south-east of France, there is an area, that's looks very much like the area around Lauscha Thüringen, also this area is famous about it's glassworks, for example the presse papiers were made there. The sparklers must have been made, in, or close to the village of Biot, in the middle of that area.
More then ones, this was told me by an antiqairian.
Cees.