Trains on Treadmills?

One of the first ever trains was powered by a horse on a treadmill. It was called the cycloped and only two of them were ever built. This was at the same time as Stevenson's rocket, which was the train that we did end up using. And it was in the same set of trials where everyone brought their own train. Is it ready to go faster than Stevenson's rocket? Really? I think it could go five miles an hour.