Mid century hollow grinding of a blade

Found this earlier. It’s in German but still was very interesting to me in spite of not knowing the language.

https://youtu.be/p63sYVCLVUk

It’s been around for quite a while but it’s a good one. I should sit down with my friend and get her to translate.

Thanks for the link. It has been a few years since I watched it.
It was interesting to watch the shower of sparks coming off the grinding wheel. That tells me he is using a hard pressure while grinding. I saw that while watching Howard Clark grind a straight razor. He is so practiced with grinding steel that he can use a goodly amount of pressure on the contact wheel and generate a ton of sparks. He grinds a razor very quickly ! :)