If you showed me something modern like that, I would have called bullshit. Just inversing tooth and register for the sake of it.
1902 though ...... that is serious experimenting and questioning. It is lovely. It is very lovely like you say. It's really hard to imagine the intricate work gone on there in a workshop and the tooling required to do that.
View attachment 887429
What repeatedly astounds me is since practically the birth of the bicycle the French went on a quest to shed any gram they saw possible, and with a style. It often feels like there was never a movement of whittling down to practically nothingness based empirically, but more like puny skinny and in it's last breath was a starting point. Probably more like can it get away with murder up front, and save the hassle shaving lard off. I think a combination of madness, faith in new human achievement and knowledge of metals must have been the pillars. You look at the cranks and pedals on that and it looks like it was on a weight watchers program for 50 years prior but it wasn't. It is documented that selling brakes early on was hindered by the extra associated weight - freewheels and gears changed all that.
https://encycloduvelo.fr/terrot/