Here's another
picture, where you can see that the seat appears to have springs in it. Presumably this would help you in the bouncing part. This chair also has posts that you could hold on to while you were bouncing. I can't imagine what you did with the other chairs. Just grabbed the arms maybe? Would your feet touch the floor? Really, trying to get this image of formally attired Regency men and women sitting on chair like that bouncing themselves up and down, I can't help but giggle. How they could do this and still retain their dignity I can't imagine.