I’ve seen a picture of this thing before, but never a promotional video. It’s sort of an overgrown monowheel, invented in 1932. Watch it get speed wobbles at 1:08. It’s not clear if there’s any mechanism to avoid gerbilling.
Still, an impressive engineering feat.
You mean the front/back swing? I think I could see a tad of side wobble @ 1:10.
The wheel is so fat it takes almost no balance skill 
I spotted this in my local museum (Kingswood Heritage Museum) this afternoon. I thought “that looks like a monocycle”. And sure enough, that’s what it was.
They’ve got so many (gorgeous) Douglas bikes on display in the museum, it’s such a pity they haven’t got one of the prototype Dynaspheres to go with them.
I would have been cool to see these wheels everywhere on the streets. I reckon at a forward collision, the inner seating section just slides forward and there must be a locking mechanism, so it doesn’t go upside down. Sad to see these contraptions having been abandoned. I would love to come to work in one.
