Actually really heavy motors transformers etc use square most of the time and the lead from the buss may be ribbons stacked to give the flexibility a heavy bar doesn't have. All I was saying (I love your thread and don't wish to hijack it) was that the reasoning behind using ribbon in a vc and using it in a rheostat are different so while one may have come from the other, it may not have. I guess if ribbon wire was already a commodity there may not even be a patent for using it in a vc, but I'd sure like to know who's idea it was and if the original reason was the reason that they have sold all these years.